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Schweikert, Michael

Michael Schweikert

Herr PD Dr.

Wissenschaftlicher Mitarbeiter
Institut für Biomaterialien und biomolekulare Systeme
Abteilung Biobasierte Materialien

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+49 711 685 65096
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Publikationen

Publikationen:

Kohl, J., Schweikert, M., Klaas, N., Lemloh, M.-L.: Intracellular bioaccumulation of the rare earth element Gadolinium in ciliate cells resulting in biogenic particle formation and excretion. Scientific Reports. 13, 5650 (2023). https://doi.org/10.1038/s41598-023-32596-3.
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@article{Kohl2023, abstract = {Ciliates are abundant unicellular organisms capable of resisting high concentrations of metal ions in the environment caused by various anthropogenic activities. Understanding the cellular pathways involved in resistance to and detoxification of elements is required to predict the impact of ciliates on environmental element cycles. Here, we investigated the so far unknown process of tolerance, cellular uptake and bioaccumulation of the emerging rare earth element gadolinium (Gd) in the common ciliate Tetrahymena pyriformis. Gd treatment results in the intracellular formation and excretion of biogenic Gd-containing particles. This cellular process effectively removes dissolved Gd from the organic growth medium by 53.37{\%} within 72 h. Based on light and electron microscopic observations, we postulate a detoxification pathway: Cells take up toxic Gd3+ ions from the medium by endocytosis, process them into stable Gd-containing particles within food vacuoles, and exocytose them. Stable biogenic particles can be isolated, which are relatively homogeneous and have a diameter of about 3 {\textmu}m. They consist of the elements Gd, C, O, P, Na, Mg, K, and Ca. These findings broaden the view of metal ion accumulation by protists and are of relevance to understand environmental elemental cycles and may inspire approaches for metal recovery or bioremediation.}, author = {Kohl, Jana and Schweikert, Michael and Klaas, Norbert and Lemloh, Marie-Louise}, day = 06, doi = {10.1038/s41598-023-32596-3}, issn = {2045-2322}, journal = {Scientific Reports}, month = {04}, number = 1, pages = 5650, title = {Intracellular bioaccumulation of the rare earth element Gadolinium in ciliate cells resulting in biogenic particle formation and excretion}, url = {https://doi.org/10.1038/s41598-023-32596-3}, volume = 13, year = 2023 }
Link
https://doi.org/10.1038/s41598-023-32596-3
Strohm, S.B., Inckemann, S.E., Gao, K., Schweikert, M., Lemloh, M.-L., Schmahl, W.W., Jordan, G.: On the nucleation of ikaite (CaCO3x6H2O) – A comparative study in the presence and absence of mineral surfaces. Chemical Geology. 611, 121089 (2022). https://doi.org/10.1016/j.chemgeo.2022.121089.
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@article{Strohm_2022, author = {Strohm, Samuel B. and Inckemann, Sebastian E. and Gao, Kun and Schweikert, Michael and Lemloh, Marie-Louise and Schmahl, Wolfgang W. and Jordan, Guntram}, doi = {10.1016/j.chemgeo.2022.121089}, journal = {Chemical Geology}, month = {11}, pages = 121089, publisher = {Elsevier {BV}}, title = {On the nucleation of ikaite ({CaCO}3x6H2O) {\textendash} A comparative study in the presence and absence of mineral surfaces}, url = {https://doi.org/10.1016%2Fj.chemgeo.2022.121089}, volume = 611, year = 2022 }
Link
https://doi.org/10.1016%2Fj.chemgeo.2022.121089
Hörning, M., Schertel, A., Schneider, R., Lemloh, M.-L., Schweikert, M.R., Weiss, I.M.: Mineralized scale patterns on the cell periphery of the chrysophyte Mallomonas determined by comparative 3D Cryo-FIB SEM data processing. Journal of Structural Biology. 209, 107403 (2020). https://doi.org/10.1016/j.jsb.2019.10.005.
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@article{H_rning_2020, author = {Hörning, Marcel and Schertel, Andreas and Schneider, Ralf and Lemloh, Marie-Louise and Schweikert, Michael R. and Weiss, Ingrid M.}, doi = {10.1016/j.jsb.2019.10.005}, journal = {Journal of Structural Biology}, month = {01}, number = 1, pages = 107403, publisher = {Elsevier {BV}}, title = {Mineralized scale patterns on the cell periphery of the chrysophyte Mallomonas determined by comparative 3D Cryo-{FIB} {SEM} data processing}, url = {https://doi.org/10.1016%2Fj.jsb.2019.10.005}, volume = 209, year = 2020 }
Link
https://doi.org/10.1016%2Fj.jsb.2019.10.005
Cavaleiro, J., Oliveira, N.B., Ribeiro, T.A., Guimarães, L.F., Fernandes, N.M., Silva-Neto, I.D., Marszaukowski, F., Wohnrath, K., Barreto, C.B., Schweikert, M., Petroni, G., Ortenzi, C., Buonanno, F., Picciani, P.H.S., Oliveira, O.N., Soares, C.A.G.: Distinguishing Activities in the Photodynamic Arsenals of the Pigmented Ciliates Blepharisma sinuosum Sawaya, 1940 and Blepharisma japonicum Suzuki, 1954 (Ciliophora: Heterotrichea). Photochemistry and Photobiology. (2020). https://doi.org/10.1111/php.13288.
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@article{Cavaleiro_2020, author = {Cavaleiro, J{\'{e}}ssica and Oliveira, Nathally B. and Ribeiro, Talita A. and Guimar{\~{a}}es, Lohaine F. and Fernandes, Noemi M. and Silva-Neto, In{\'{a}}cio D. and Marszaukowski, Fl{\'{a}}via and Wohnrath, Karen and Barreto, Cleber B. and Schweikert, Michael and Petroni, Giulio and Ortenzi, Claudio and Buonanno, Federico and Picciani, Paulo H. S. and Oliveira, Osvaldo N. and Soares, Carlos Augusto G.}, doi = {10.1111/php.13288}, journal = {Photochemistry and Photobiology}, month = {06}, publisher = {Wiley}, title = {Distinguishing Activities in the Photodynamic Arsenals of the Pigmented Ciliates Blepharisma sinuosum Sawaya, 1940 and Blepharisma japonicum Suzuki, 1954 (Ciliophora: Heterotrichea)}, url = {https://doi.org/10.1111%2Fphp.13288}, year = 2020 }
Link
https://doi.org/10.1111%2Fphp.13288
Gerbersdorf, S.U., Koca, K., deBeer, D., Chennu, A., Noss, C., Risse-Buhl, U., Weitere, M., Eiff, O., Wagner, M., Aberle, J., Schweikert, M., Terheiden, K.: Exploring flow-biofilm-sediment interactions: Assessment of current status and future challenges. Water Research. 116182 (2020). https://doi.org/10.1016/j.watres.2020.116182.
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@article{Gerbersdorf_2020, author = {Gerbersdorf, Sabine Ulrike and Koca, Kaan and deBeer, Dirk and Chennu, Arjun and Noss, Christian and Risse-Buhl, Ute and Weitere, Markus and Eiff, Olivier and Wagner, Michael and Aberle, Jochen and Schweikert, Michael and Terheiden, Kristina}, doi = {10.1016/j.watres.2020.116182}, journal = {Water Research}, month = {07}, pages = 116182, publisher = {Elsevier {BV}}, title = {Exploring flow-biofilm-sediment interactions: Assessment of current status and future challenges}, url = {https://doi.org/10.1016%2Fj.watres.2020.116182}, year = 2020 }
Link
https://doi.org/10.1016%2Fj.watres.2020.116182
Junghans, L., Teleki, A., Wijaya, A.W., Becker, M., Schweikert, M., Takors, R.: From nutritional wealth to autophagy: In vivo metabolic dynamics in the cytosol, mitochondrion and shuttles of IgG producing CHO cells. Metabolic Engineering. 54, 145--159 (2019). https://doi.org/10.1016/j.ymben.2019.02.005.
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@article{Junghans_2019, author = {Junghans, Lisa and Teleki, Attila and Wijaya, Andy Wiranata and Becker, Max and Schweikert, Michael and Takors, Ralf}, doi = {10.1016/j.ymben.2019.02.005}, journal = {Metabolic Engineering}, month = {07}, pages = {145--159}, publisher = {Elsevier {BV}}, title = {From nutritional wealth to autophagy: In vivo metabolic dynamics in the cytosol, mitochondrion and shuttles of {IgG} producing {CHO} cells}, url = {https://doi.org/10.1016%2Fj.ymben.2019.02.005}, volume = 54, year = 2019 }
Link
https://doi.org/10.1016%2Fj.ymben.2019.02.005
Schweikert, M.: Beiträge zu den Algen Baden-Württembergs, Bd. 2 e Euglenozoa Verlag Manfred Hennecke. (2018).
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@book{schweikert2018beitrge, author = {Schweikert, Michael}, title = {Beiträge zu den Algen Baden-Württembergs, Bd. 2 e Euglenozoa Verlag Manfred Hennecke}, year = 2018 }
Potekhin, A., Schweikert, M., Nekrasova, I., Vitali, V., Schwarzer, S., Anikina, A., Kaltz, O., Petroni, G., Schrallhammer, M.: Complex life cycle, broad host range and adaptation strategy of the intranuclear Paramecium symbiont Preeria caryophila comb. nov. FEMS Microbiology Ecology. 94, (2018). https://doi.org/doi.org/10.1093/femsec/fiy076.
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@article{noauthororeditor2018complex, abstract = {Holospora and related bacteria are a group of obligate Paramecium symbionts. Characteristic features are their infectivity, the presence of two distinct morphotypes, and usually a strict specialization for a single Paramecium species as host and for a nuclear compartment (either somatic or generative nucleus) for reproduction. Holospora caryophila steps out of line, naturally occurring in Paramecium biaurelia and Paramecium caudatum. This study addresses the phylogenetic relationship among H. caryophila and other Holospora species based on 16S rRNA gene sequence comparison analyzing the type strain and seven new macronuclear symbionts. Key aspects of Holospora physiology such as infectivity, symbiosis establishment and host range were determined by comprehensive infection assays. Detailed morphological investigations and sequence-based phylogeny confirmed a high similarity between the type strain of H. caryophila and the novel strains. Surprisingly, they are only distantly related to other Holospora species suggesting that they belong to a new genus within the family Holosporaceae, here described as Preeria caryophila comb. nov. Adding to this phylogenetic distance, we also observed a much broader host range, comprising at least eleven Paramecium species. As these potential host species exhibit substantial differences in frequency of sexual processes, P. caryophila demonstrates which adaptations are crucial for macronuclear symbionts facing regular destruction of their habitat.}, author = {Potekhin, Alexey and Schweikert, Michael and Nekrasova, Irina and Vitali, Valerio and Schwarzer, Sabine and Anikina, Arina and Kaltz, Oliver and Petroni, Giulio and Schrallhammer, Martina}, doi = {doi.org/10.1093/femsec/fiy076}, journal = {FEMS Microbiology Ecology}, month = {07}, number = 7, title = {Complex life cycle, broad host range and adaptation strategy of the intranuclear Paramecium symbiont Preeria caryophila comb. nov}, volume = 94, year = 2018 }
Southan, A., Lang, T., Schweikert, M., Tovar, G.E.M., Wege, C., Eiben, S.: Covalent incorporation of tobacco mosaic virus increases the stiffness of poly(ethylene glycol) diacrylate hydrogels. RSC Adv. 8, 4686–4694 (2018). https://doi.org/10.1039/C7RA10364F.
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@article{C7RA10364F, abstract = {Hydrogels are versatile materials{,} finding applications as adsorbers{,} supports for biosensors and biocatalysts or as scaffolds for tissue engineering. A frequently used building block for chemically cross-linked hydrogels is poly(ethylene glycol) diacrylate (PEG-DA). However{,} after curing{,} PEG-DA hydrogels cannot be functionalized easily. In this contribution{,} the stiff{,} rod-like tobacco mosaic virus (TMV) is investigated as a functional additive to PEG-DA hydrogels. TMV consists of more than 2000 identical coat proteins and can therefore present more than 2000 functional sites per TMV available for coupling{,} and thus has been used as a template or building block for nano-scaled hybrid materials for many years. Here{,} PEG-DA (Mn = 700 g mol−1) hydrogels are combined with a thiol-group presenting TMV mutant (TMVCys). By covalent coupling of TMVCys into the hydrogel matrix via the thiol-Michael reaction{,} the storage modulus of the hydrogels is increased compared to pure PEG-DA hydrogels and to hydrogels containing wildtype TMV (wt-TMV) which is not coupled covalently into the hydrogel matrix. In contrast{,} the swelling behaviour of the hydrogels is not altered by TMVCys or wt-TMV. Transmission electron microscopy reveals that the TMV particles are well dispersed in the hydrogels without any large aggregates. These findings give rise to the conclusion that well-defined hydrogels were obtained which offer the possibility to use the incorporated TMV as multivalent carrier templates e.g. for enzymes in future studies.}, author = {Southan, A. and Lang, T. and Schweikert, M. and Tovar, G. E. M. and Wege, C. and Eiben, S.}, doi = {10.1039/C7RA10364F}, journal = {RSC Adv.}, number = 9, pages = {4686-4694}, publisher = {The Royal Society of Chemistry}, title = {Covalent incorporation of tobacco mosaic virus increases the stiffness of poly(ethylene glycol) diacrylate hydrogels}, url = {http://dx.doi.org/10.1039/C7RA10364F}, volume = 8, year = 2018 }
Link
http://dx.doi.org/10.1039/C7RA10364F
Siegmund, L., Schweikert, M., Fischer, M.S., Wostemeyer, J.: Bacterial Surface Traits Influence Digestion by Tetrahymena pyriformis and Alter Opportunity to Escape from Food Vacuoles. Journal of Eukaryotic Microbiology. 65, (2018). https://doi.org/10.1111/jeu.12504.
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@article{siegmund2018bacterial, abstract = {Endosymbiotic interactions are frequently found in nature, especially in the group of protists. Even though many endosymbioses have been studied in detail, little is known about the mechanistic origins and physiological prerequisites of endosymbiont establishment. A logical step towards the development of endocytobiotic associations is evading digestion and escaping from the host's food vacuoles. Surface properties of bacteria are probably involved in these processes. Therefore, we chemically modified the surface of a transformant strain of Escherichia coli prior to feeding to Tetrahymena pyriformis . N‐(3‐dimethylaminopropyl)‐N’‐ethylcarbodiimide allows any substance carrying amino‐ or carboxyl groups to be bound covalently to the bacterial surface by forming a peptide bond, thus, altering its properties biochemically and biophysically in a predictable manner. The effect of different traits on digestion of T. pyriformis was examined by fluorescence and transmission electron microscopy. The efficiency of digestion differs considerably depending on the coupled substances. Alkaline substances inhibit digestion partially, resulting in incomplete digestion and slightly enhanced escape rates. Increasing hydrophobicity leads to much higher escape frequencies. Both results point to possible mechanisms employed by pathogenic bacteria or potential endosymbionts in evading digestion and transmission to the host's cytoplasm.}, author = {Siegmund, Lisa and Schweikert, Michael and Fischer, Martin S. and Wostemeyer, Johannes}, doi = {10.1111/jeu.12504}, journal = {Journal of Eukaryotic Microbiology}, month = {01}, number = 5, title = {Bacterial Surface Traits Influence Digestion by Tetrahymena pyriformis and Alter Opportunity to Escape from Food Vacuoles}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/jeu.12504}, volume = 65, year = 2018 }
Link
https://onlinelibrary.wiley.com/doi/abs/10.1111/jeu.12504
Sabaneyeva, E., Castelli, M., Szokoli, F., Benken, K., Lebedeva, N., Salvetti, A., Schweikert, M., Fokin, S., Petroni, G.: Host and Symbiont Intraspecific Variability: The Case of Paramecium Calkinsi and ``Candidatus Trichorickettsia Mobilis’’. European Journal of Protistology. 62, 79–94 (2018). https://doi.org/10.1016/j.ejop.2017.12.002.
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@article{Sabaneyeva_EJoP_2018, abstract = {Newly isolated strains of the ciliate Paramecium calkinsi and their cytoplasmic bacterial endosymbionts were characterized by a multidisciplinary approach, including live observation, ultrastructural investigation, and molecular analysis. Despite morphological resemblance, the characterized P. calkinsi strains showed a significant molecular divergence compared to conspecifics, possibly hinting for a cryptic speciation. The endosymbionts were clearly found to be affiliated to the species ``Candidatus Trichorickettsia mobilis'' (Rickettsiales, Rickettsiaceae), currently encompassing only bacteria retrieved in an obligate intracellular association with other ciliates. However, a relatively high degree of intraspecific divergence was observed as well, thus it was possible to split ``Candidatus Trichorickettsia'' into three subspecies, one of which represented so far only by the newly characterized endosymbionts of P. calkinsi. Other features distinguished the members of each different subspecies. In particular, the endosymbionts of P. calkinsi resided in the cytoplasm and possessed numerous peritrichous flagella, although no motility was evidenced, whereas their conspecifics in other hosts were either cytoplasmic and devoid of flagella, or macronuclear, displaying flagellar-driven motility. Moreover, contrarily to previously analyzed ``Candidatus Trichorickettsia'' hosts, infected P. calkinsi cells frequently became amicronucleate and demonstrated abnormal cell division, eventually leading to decline of the laboratory culture.}, author = {Sabaneyeva, E. and Castelli, M. and Szokoli, F. and Benken, K. and Lebedeva, N. and Salvetti, A. and Schweikert, M. and Fokin, S. and Petroni, G.}, doi = {10.1016/j.ejop.2017.12.002}, file = {/home/mike/Zotero/storage/4HSACUQS/Sabaneyeva et al. - 2018 - Host and symbiont intraspecific variability The c.pdf;/home/mike/Zotero/storage/WWEDWUQB/S0932473917301372.html}, issn = {0932-4739}, journal = {European Journal of Protistology}, month = {02}, pages = {79-94}, shorttitle = {Host and Symbiont Intraspecific Variability}, title = {Host and Symbiont Intraspecific Variability: {{The}} Case of {{Paramecium}} Calkinsi and ``{{Candidatus Trichorickettsia}} Mobilis''}, volume = 62, year = 2018 }
da Silva Paiva, T., Küppers, G.C., Lahr, D.J.G., Schweikert, M., da Silva-Neto, I.D.: Discomorphella pedroeneasi Sp. Nov. (Ciliophora, Odontostomatida): An Anaerobic Ciliate Hosting Multiple Cytoplasmic and Macronuclear Endocytobionts. European Journal of Protistology. 58, 103–134 (2017). https://doi.org/10.1016/j.ejop.2017.01.002.
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@article{daSilvaPaiva_EJoP_2017, abstract = {Odontostomatids are among the less studied representatives of the Ciliophora. They are anaerobic microeukaryotes usually occurring as rare species in sapropelic environments. Here we describe a novel species of Discomorphella, named Discomorphella pedroeneasi sp. nov., using light and electron microscopy observations. Discomorphella pedroeneasi displays many complex morphological features, for which new terms are introduced, such as the auricules, epistomial fringe spacer, frontal awning, odontostomatid ciliary sockets, oral lips and ventral flap. Remarkably, D. pedroeneasi has at least six types of endocytobionts, including intramacronuclear ones, and organelles ultrastructurally similar to the M/H bodies of the odontostomatid Saprodinium dentatum. Based on the new data and revision of the literature, we propose two new diagnostic characters for species separation within Discomorphella: the fringe spacer ratio and the posterior fringe ratio. The taxonomy of Discomorphella is revised and an identification key is provided.}, author = {{da Silva Paiva}, Thiago and K\"uppers, Gabriela Cristina and Lahr, Daniel Jos\'e Galafasse and Schweikert, Michael and {da Silva-Neto}, In\'acio Domingos}, doi = {10.1016/j.ejop.2017.01.002}, file = {/home/mike/Zotero/storage/FMJJH6VC/da Silva Paiva et al. - 2017 - Discomorphella pedroeneasi sp. nov. (Ciliophora, O.pdf;/home/mike/Zotero/storage/HRGETWQE/S0932473917300068.html}, issn = {0932-4739}, journal = {European Journal of Protistology}, month = {04}, pages = {103-134}, shorttitle = {Discomorphella Pedroeneasi Sp. Nov. ({{Ciliophora}}, {{Odontostomatida}})}, title = {Discomorphella pedroeneasi Sp. Nov. ({{Ciliophora}}, {{Odontostomatida}}): {{An}} Anaerobic Ciliate Hosting Multiple Cytoplasmic and Macronuclear Endocytobionts}, volume = 58, year = 2017 }
Sabaneyeva, E., Castelli, M., Szokoli, F., Benken, K., Lebedeva, N., Salvetti, A., Schweikert, M., Fokin, S., Petroni, G.: Host and Symbiont Intraspecific Variability: The Case of Paramecium Calkinsi and “Candidatus Trichorickettsia Mobilis.” (2017). https://doi.org/10.1016/j.ejop.2017.12.002.
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@book{Sabaneyeva__2017, abstract = {Newly isolated strains of the ciliate Paramecium calkinsiandtheircytoplasmicbacterialendosymbiontswerecharacterizedbyamultidisciplinaryapproach,includingliveobservation,ultrastructuralinvestigation,andmolecularanalysis.Despitemorpho-logicalresemblance,thecharacterizedP.calkinsistrainsshowedasignificantmoleculardivergencecomparedtoconspecifics,possiblyhintingforacrypticspeciation.Theendosymbiontswereclearlyfoundtobeaffiliatedtothespecies``CandidatusTrichorickettsiamobilis''(Rickettsiales,Rickettsiaceae),currentlyencompassingonlybacteriaretrievedinanobligateintracel-lularassociationwithotherciliates.However,arelativelyhighdegreeofintraspecificdivergencewasobservedaswell,thusitwaspossibletosplit``CandidatusTrichorickettsia''intothreesubspecies,oneofwhichrepresentedsofaronlybythenewlycharacterizedendosymbiontsofP.calkinsi.Otherfeaturesdistinguishedthemembersofeachdifferentsubspecies.Inparticular,theendosymbiontsofP.calkinsiresidedinthecytoplasmandpossessednumerousperitrichousflagella,althoughnomotilitywasevidenced,whereastheirconspecificsinotherhostswereeithercytoplasmicanddevoidofflagella,ormacronuclear,displayingflagellar-drivenmotility.Moreover,contrarilytopreviouslyanalyzed``CandidatusTrichorickettsia''hosts,infectedP.calkinsicellsfrequentlybecameamicronucleateanddemonstratedabnormalcelldivision,eventuallyleadingtodeclineofthelaboratoryculture.}, author = {Sabaneyeva, Elena and Castelli, Michele and Szokoli, Franziska and Benken, Konstantin and Lebedeva, Natalia and Salvetti, A and Schweikert, Michael and Fokin, Sergei and Petroni, Giulio}, doi = {10.1016/j.ejop.2017.12.002}, month = {12}, shorttitle = {Host and Symbiont Intraspecific Variability}, title = {Host and Symbiont Intraspecific Variability: {{The}} Case of {{Paramecium}} Calkinsi and "{{Candidatus Trichorickettsia}} Mobilis"}, volume = 62, year = 2017 }
Grossmann, L., Bock, C., Schweikert, M., Boenigk, J.: Small but Manifold – Hidden Diversity in ``Spumella-like Flagellates’’. The Journal of Eukaryotic Microbiology. 63, 419–439 (2016). https://doi.org/10.1111/jeu.12287.
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@article{Grossmann_JEM_2016, abstract = {Colourless, nonscaled chrysophytes comprise morphologically similar or even indistinguishable flagellates which are important bacterivors in water and soil crucial for ecosystem functioning. However, phylogenetic analyses indicate a multiple origin of such colourless, nonscaled flagellate lineages. These flagellates are often referred to as ``Spumella-like flagellates'' in ecological and biogeographic studies. Although this denomination reflects an assumed polyphyly, it obscures the phylogenetic and taxonomic diversity of this important flagellate group and, thus, hinders progress in lineage- and taxon-specific ecological surveys. The smallest representatives of colourless chrysophytes have been addressed in very few taxonomic studies although they are among the dominant flagellates in field communities. To overcome the blurred picture and set the field for further investigation in biogeography and ecology of the organisms in question, we studied a set of strains of specifically small, colourless, nonscaled chrysomonad flagellates by means of electron microscopy and molecular analyses. They were isolated by a filtration-acclimatisation approach focusing on flagellates of around 5~$\mu$m. We present the phylogenetic position of eight different lineages on both the ordinal and the generic level. Accordingly, we describe the new genera Apoikiospumella, Chromulinospumella, Segregatospumella, Cornospumella and Acrispumella Boenigk et Grossmann n. g. and different species within them.}, author = {Grossmann, Lars and Bock, Christina and Schweikert, Michael and Boenigk, Jens}, doi = {10.1111/jeu.12287}, file = {/home/mike/Zotero/storage/HUJWSQIS/Grossmann et al. - 2016 - Small but Manifold – Hidden Diversity in “Spumella.pdf}, issn = {1066-5234}, journal = {The Journal of Eukaryotic Microbiology}, number = 4, pages = {419-439}, pmcid = {PMC5066751}, pmid = {26662881}, title = {Small but {{Manifold}} \textendash{} {{Hidden Diversity}} in ``{{Spumella}}-like {{Flagellates}}''}, volume = 63, year = 2016 }
Schweikert, M.: Biology of parasitic heterotrophic nanoflagellates : parasitoids of diatoms. Springer Japan, Tokyo (2015). https://doi.org/10.1007/978-4-431-55130-0_21.
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@book{schweikert2015biology, abstract = {Heterotrophic nanoflagellates are important consumers of bacteria in all environments. Nowadays, some few exceptions are known, termed parasitic nanoflagellates (PNF ), feeding on much larger prey in marine waters. They are feeding on planktonic and benthic diatoms. Since these flagellates inevitably kill their host they are parasitoids rather than parasites despite the use of the term PNF. The name parasitic nanoflagellate refers to an ecological function rather than to taxonomic entities, since these organisms correspond to different taxonomic groups. It can be expected that the diversity of PNF is much greater than known so far, since reports of undescribed species can be found in the literature. Examples of different parasitoidic nanoflagellates are given here. Morphological features and taxonomic positions of these species, as well as their sophisticated modes of infection and food acquisition, will be described.}, address = {Tokyo}, author = {Schweikert, Michael}, doi = {10.1007/978-4-431-55130-0_21}, editor = {Ohtsuka, Sususmu and Suzaki, Toshinobu and Horiguchi, Takeo and Suzuki, Noritoshi and Not, Fabrice}, month = {01}, number = {Chapter 22}, publisher = {Springer Japan}, series = {Marine Protists, Diversity and Dynamics}, title = {Biology of parasitic heterotrophic nanoflagellates : parasitoids of diatoms}, volume = {Part II}, year = 2015 }
Vannini, C., Boscaro, V., Ferrantini, F., Benken, K.A., Mironov, T.I., Schweikert, M., Görtz, H.-D., Fokin, S.I., Sabaneyeva, E.V., Petroni, G.: Flagellar Movement in Two Bacteria of the Family Rickettsiaceae: A Re-Evaluation of Motility in an Evolutionary Perspective. PLOS ONE. 9, e87718 (2014). https://doi.org/10.1371/journal.pone.0087718.
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@article{Vannini_PO_2014, abstract = {Bacteria of the family Rickettsiaceae have always been largely studied not only for their importance in the medical field, but also as model systems in evolutionary biology. In fact, they share a recent common ancestor with mitochondria. The most studied species, belonging to genera Rickettsia and Orientia, are hosted by terrestrial arthropods and include many human pathogens. Nevertheless, recent findings show that a large part of Rickettsiaceae biodiversity actually resides outside the group of well-known pathogenic bacteria. Collecting data on these recently described non-conventional members of the family is crucial in order to gain information on ancestral features of the whole group. Although bacteria of the family Rickettsiaceae, and of the whole order Rickettsiales, are formally described as non-flagellated prokaryotes, some recent findings renewed the debate about this feature. In this paper we report the first finding of members of the family displaying numerous flagella and active movement inside their host cells. These two new taxa are hosted in aquatic environments by protist ciliates and are described here by means of ultrastructural and molecular characterization. Data here reported suggest that the ancestor of Rickettsiales displayed flagellar movement and re-evaluate the hypothesis that motility played a key-role in the origin of mitochondria. Moreover, our study highlights that the aquatic environment represents a well exploited habitat for bacteria of the family Rickettsiaceae. Our results encourage a deep re-consideration of ecological and morphological traits of the family and of the whole order.}, author = {Vannini, Claudia and Boscaro, Vittorio and Ferrantini, Filippo and Benken, Konstantin A. and Mironov, Timofei I. and Schweikert, Michael and G\"ortz, Hans-Dieter and Fokin, Sergei I. and Sabaneyeva, Elena V. and Petroni, Giulio}, doi = {10.1371/journal.pone.0087718}, file = {/home/mike/Zotero/storage/28X8EET2/Vannini et al. - 2014 - Flagellar Movement in Two Bacteria of the Family R.pdf}, issn = {1932-6203}, journal = {PLOS ONE}, month = {02}, number = 2, pages = {e87718}, shorttitle = {Flagellar {{Movement}} in {{Two Bacteria}} of the {{Family Rickettsiaceae}}}, title = {Flagellar {{Movement}} in {{Two Bacteria}} of the {{Family Rickettsiaceae}}: {{A Re}}-{{Evaluation}} of {{Motility}} in an {{Evolutionary Perspective}}}, volume = 9, year = 2014 }
de Castro, L.A.M., Küppers, G.C., Schweikert, M., Harada, M.L., Paiva, T. da S.: Ciliates from Eutrophized Water in the Northern Brazil and Morphology of Cristigera Hammeri Wilbert, 1986 (Ciliophora, Scuticociliatia). European Journal of Protistology. 50, 122–133 (2014). https://doi.org/10.1016/j.ejop.2014.01.005.
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@article{deCastro_EJoP_2014, abstract = {Ciliates occur in all major aquatic and soil environments worldwide and are important links in the microbial food webs, which, along with other free-living protists, are generally overlooked in biodiversity conservation programs. In Brazil, the northern region comprises the Brazilian Amazonia, an area widely known for its huge biodiversity. However, the diversity of ciliates in that region is still almost unknown. As result of the present study, a total of 21 species of ciliates, distributed among 15 genera, were inventoried from samples of eutrophized water collected in the city of Bel\'em, capital of the state of Par\'a, one of the states which comprise the Brazilian Amazonia. In addition, a local population of the rare scuticociliate Cristigera hammeri is described from optical and electron microscopy observations, and its synonymy with C. pleuronemoides is rejected based on new evidence.}, author = {{de Castro}, Larissa Araguaia Monteiro and K\"uppers, Gabriela Cristina and Schweikert, Michael and Harada, Maria L\'ucia and Paiva, Thiago da Silva}, doi = {10.1016/j.ejop.2014.01.005}, file = {/home/mike/Zotero/storage/UG8AQNF7/de Castro et al. - 2014 - Ciliates from eutrophized water in the northern Br.pdf;/home/mike/Zotero/storage/TUHM79NV/S0932473914000157.html}, issn = {0932-4739}, journal = {European Journal of Protistology}, month = {04}, number = 2, pages = {122-133}, title = {Ciliates from Eutrophized Water in the Northern {{Brazil}} and Morphology of {{Cristigera}} Hammeri {{Wilbert}}, 1986 ({{Ciliophora}}, {{Scuticociliatia}})}, volume = 50, year = 2014 }
Urban, C., Sohn, K., Lottspeich, F., Brunner, H., Rupp, S.: Identification of Cell Surface Determinants in Candida Albicans Reveals Tsa1p, a Protein Differentially Localized in the Cell. FEBS Letters. 544, 228–235 (2013). https://doi.org/10.1016/S0014-5793(03)00455-1.
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@article{Urban_FL_2013, abstract = {To identify cell surface proteins of Candida albicans, the predominant fungal pathogen in humans, we have established an approach using a membrane impermeable biotin derivative in combination with affinity purification. We were able to identify 29 different proteins under two distinct conditions. Among mannoproteins, heat shock proteins and glycolytic enzymes we found thiol-specific antioxidant-like protein 1 (Tsa1p) to be differentially localized depending on the conditions applied. Only in hyphally grown cells Tsa1p was localized to the cell surface whereas in blastospores no surface but mainly nuclear localization was found. This indicates that cell surface expression of at least some proteins is mediated by differential translocation.}, author = {Urban, C and Sohn, K and Lottspeich, F and Brunner, H and Rupp, S}, copyright = {All rights reserved}, doi = {10.1016/S0014-5793(03)00455-1}, file = {/home/mike/Zotero/storage/DHAZDMF9/Urban et al. - 2003 - Identification of cell surface determinants in Can.pdf;/home/mike/Zotero/storage/ZGY92I5F/S0014579303004551.html}, issn = {0014-5793}, journal = {FEBS Letters}, month = {06}, number = 1, pages = {228-235}, title = {Identification of Cell Surface Determinants in {{Candida}} Albicans Reveals {{Tsa1p}}, a Protein Differentially Localized in the Cell}, volume = 544, year = 2013 }
Hoppenrath, M., Chomérat, N., Horiguchi, T., Schweikert, M., Nagahama, Y., Murray, S.: Taxonomy and Phylogeny of the Benthic Prorocentrum Species (Dinophyceae)A Proposal and Review. Harmful Algae. 27, 1–28 (2013). https://doi.org/10.1016/j.hal.2013.03.006.
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@article{Hoppenrath_HA_2013, abstract = {Based on a literature review and new morphological and molecular phylogenetic data, a summary of all described benthic Prorocentrum species is presented. Short descriptions of the 29 species are provided including information and illustrations of platelet pattern. Increasing morphological data of the same taxon from different sites has revealed unexpected morphological variability. The variability of characters used for taxonomy is discussed. Many of these may be more variable than previously thought or phenotypically plastic. We conclude that the following features are constant within a species: (1) asymmetry or symmetry of the theca in combination with (2) the shape of the periflagellar area visible on the right thecal plate, (a) arc-shaped, (b) wide or simply V-shaped, (c) narrow and deep V-shaped, and (d) linear. At the same time, we are now beginning to understand that the cell shape of some species is more variable than thought and not in others. The stability of pore patterns is not known to date nor is it known whether the presence of a starch sheath is a reliable taxonomic character. The morphology of the periflagellar area might be a very useful character. The unstable terminology to describe similar or identical structures has made it difficult to interpret the literature on these features. Therefore a unified revised terminology for morphological features, cell orientation, and platelet numbering are proposed. This review highlights uncertainty in species boundaries of several potentially toxin producing species. This includes the species Prorocentrum hoffmannianum, Prorocentrum belizeanum, Prorocentrum maculosum, and Prorocentrum faustiae. Some species are reported to have variable toxicity, e.g. P. belizeanum and Prorocentrum rhathymum. It is clear that several species complexes, containing genetically related cryptic species, are present. The species complexes proposed in the past and in this paper reflect the difficulties in distinguishing these species, which may be highly morphologically similar to one another, sometimes despite genetic differences. Additionally, the growing molecular data set has allowed us to evaluate current species concepts based on novel molecular genetic information. As some Prorocentrum species are potentially toxic and are included in monitoring programs, it is important to evaluate species boundaries as currently understood, and to determine our current knowledge gaps regarding the relationship between species and strain identification and toxin production.}, author = {Hoppenrath, Mona and Chom\'erat, Nicolas and Horiguchi, Takeo and Schweikert, Michael and Nagahama, Yukio and Murray, Shauna}, doi = {10.1016/j.hal.2013.03.006}, file = {/home/mike/Zotero/storage/5KZPEYZ7/Hoppenrath et al. - 2013 - Taxonomy and phylogeny of the benthic Prorocentrum.pdf;/home/mike/Zotero/storage/JVA2YI5U/S1568988313000498.html}, issn = {1568-9883}, journal = {Harmful Algae}, month = {07}, pages = {1-28}, title = {Taxonomy and Phylogeny of the Benthic {{Prorocentrum}} Species ({{Dinophyceae}})\textemdash{{A}} Proposal and Review}, volume = 27, year = 2013 }
Schrallhammer, M., Ferrantini, F., Vannini, C., Galati, S., Schweikert, M., Görtz, H.-D., Verni, F., Petroni, G.: `Candidatus Megaira Polyxenophila’ Gen. Nov., Sp. Nov.: Considerations on Evolutionary History, Host Range and Shift of Early Divergent Rickettsiae. PLOS ONE. 8, e72581 (2013). https://doi.org/10.1371/journal.pone.0072581.
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@article{Schrallhammer_PO_2013, abstract = {``Neglected Rickettsiaceae'' (i.e. those harboured by non-hematophagous eukaryotic hosts) display greater phylogenetic variability and more widespread dispersal than pathogenic ones; yet, the knowledge about their actual host range and host shift mechanism is scarce. The present work reports the characterization following the full-cycle rRNA approach (SSU rRNA sequence, specific in situ hybridization, and ultrastructure) of a novel rickettsial bacterium, herewith proposed as 'Candidatus Megaira polyxenophila' gen. nov., sp. nov. We found it in association with four different free-living ciliates (Diophrys oligothrix, Euplotes octocarinatus, Paramecium caudatum, and Spirostomum sp., all belonging to Alveolata, Ciliophora); furthermore it was recently observed as intracellular occurring in Carteria cerasiformis and Pleodorina japonica (Chlorophyceae, Chlorophyta). Phylogenetic analyses demonstrated the belonging of the candidate new genus to the family Rickettsiaceae (Alphaproteobacteria, Rickettsiales) as a sister group of the genus Rickettsia. In situ observations revealed the ability of the candidate new species to colonize either nuclear or cytoplasmic compartments, depending on the host organism. The presence of the same bacterial species within different, evolutionary distant, hosts indicates that 'Candidatus Megaira polyxenophila' recently underwent several distinct host shifts, thus suggesting the existence of horizontal transmission pathways. We consider these findings as indicative of an unexpected spread of rickettsial infections in aquatic communities, possibly by means of trophic interactions, and hence propose a new interpretation of the origin and phylogenetic diversification of rickettsial bacteria.}, author = {Schrallhammer, Martina and Ferrantini, Filippo and Vannini, Claudia and Galati, Stefano and Schweikert, Michael and G\"ortz, Hans-Dieter and Verni, Franco and Petroni, Giulio}, doi = {10.1371/journal.pone.0072581}, file = {/home/mike/Zotero/storage/5RUT44MT/Schrallhammer et al. - 2013 - ‘Candidatus Megaira polyxenophila’ gen. nov., sp. .pdf;/home/mike/Zotero/storage/FL9FHAB4/article.html}, issn = {1932-6203}, journal = {PLOS ONE}, month = {08}, number = 8, pages = {e72581}, shorttitle = {`{{Candidatus Megaira}} Polyxenophila' Gen. Nov., Sp. Nov.}, title = {`{{Candidatus Megaira}} Polyxenophila' Gen. Nov., Sp. Nov.: {{Considerations}} on {{Evolutionary History}}, {{Host Range}} and {{Shift}} of {{Early Divergent Rickettsiae}}}, volume = 8, year = 2013 }
Boscaro, V., Schrallhammer, M., Benken, K.A., Krenek, S., Szokoli, F., Berendonk, T.U., Schweikert, M., Verni, F., Sabaneyeva, E.V., Petroni, G.: Rediscovering the Genus Lyticum, Multiflagellated Symbionts of the Order Rickettsiales. Scientific Reports. 3, (2013). https://doi.org/10.1038/srep03305.
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@article{Boscaro_SR_2013, abstract = {Among the bacterial symbionts harbored by the model organism Paramecium, many still lack a recent investigation that includes a molecular characterization. The genus Lyticum consists of two species of large-sized bacteria displaying numerous flagella, despite their inability to move inside their hosts' cytoplasm. We present a multidisciplinary redescription of both species, using the deposited type strains as well as newly collected material. On the basis of 16S rRNA gene sequences, we assigned Lyticum to the order Rickettsiales, that is intensely studied because of its pathogenic representatives and its position as the extant group most closely related to the mitochondrial ancestor. We provide conclusive proofs that at least some Rickettsiales possess actual flagella, a feature that has been recently predicted from genomic data but never confirmed. We give support to the hypothesis that the mitochondrial ancestor could have been flagellated, and provide the basis for further studies on these ciliate endosymbionts.}, author = {Boscaro, Vittorio and Schrallhammer, Martina and Benken, Konstantin A. and Krenek, Sascha and Szokoli, Franziska and Berendonk, Thomas U. and Schweikert, Michael and Verni, Franco and Sabaneyeva, Elena V. and Petroni, Giulio}, doi = {10.1038/srep03305}, file = {/home/mike/Zotero/storage/G7GUK49V/Boscaro et al. - 2013 - Rediscovering the genus Lyticum, multiflagellated .pdf}, issn = {2045-2322}, journal = {Scientific Reports}, month = {11}, pmcid = {PMC3837311}, pmid = {24264310}, title = {Rediscovering the Genus {{Lyticum}}, Multiflagellated Symbionts of the Order {{Rickettsiales}}}, volume = 3, year = 2013 }
Lemloh, M.-L., Marin, F., Herbst, F., Plasseraud, L., Schweikert, M., Baier, J., Bill, J., Brümmer, F.: Genesis of Amorphous Calcium Carbonate Containing Alveolar Plates in the Ciliate Coleps Hirtus (Ciliophora, Prostomatea). Journal of Structural Biology. 181, 155–161 (2013). https://doi.org/10.1016/j.jsb.2012.12.001.
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@article{Lemloh_JoSB_2013, abstract = {In the protist world, the ciliate Coleps hirtus (phylum Ciliophora, class Prostomatea) synthesizes a peculiar biomineralized test made of alveolar plates, structures located within alveolar vesicles at the cell cortex. Alveolar plates are arranged by overlapping like an armor and they are thought to protect and/or stiffen the cell. Although their morphology is species-specific and of complex architecture, so far almost nothing is known about their genesis, their structure and their elemental and mineral composition. We investigated the genesis of new alveolar plates after cell division and examined cells and isolated alveolar plates by electron microscopy, energy-dispersive X-ray spectroscopy, FTIR and X-ray diffraction. Our investigations revealed an organic mesh-like structure that guides the formation of new alveolar plates like a template and the role of vesicles transporting inorganic material. We further demonstrated that the inorganic part of the alveolar plates is composed out of amorphous calcium carbonate. For stabilization of the amorphous phase, the alveolar vesicles, the organic fraction and the element phosphorus may play a role.}, author = {Lemloh, Marie-Louise and Marin, Fr\'ed\'eric and Herbst, Fr\'ed\'eric and Plasseraud, Laurent and Schweikert, Michael and Baier, Johannes and Bill, Joachim and Br\"ummer, Franz}, doi = {10.1016/j.jsb.2012.12.001}, file = {/home/mike/Zotero/storage/MAKR7UVK/Lemloh et al. - 2013 - Genesis of amorphous calcium carbonate containing .pdf;/home/mike/Zotero/storage/7FVRKWEE/S104784771200319X.html}, issn = {1047-8477}, journal = {Journal of Structural Biology}, month = {02}, number = 2, pages = {155-161}, title = {Genesis of Amorphous Calcium Carbonate Containing Alveolar Plates in the Ciliate {{Coleps}} Hirtus ({{Ciliophora}}, {{Prostomatea}})}, volume = 181, year = 2013 }
Schweikert, M., Fujishima, M., Görtz, H.-D.: Symbiotic Associations Between Ciliates and Prokaryotes. In: The Prokaryotes. pp. 427–463. Springer, Berlin, Heidelberg (2013). https://doi.org/10.1007/978-3-642-30194-0_18.
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@incollection{Schweikert_TP_2013, abstract = {According to the huge diversity of protists, symbioses with eukaryotes and prokaryotes were established frequently during evolution. Ciliates were in focus of researchers since the beginning of research on unicellular organisms, after invention of the light microscope. Nowadays, in ciliates the known endosymbiotic diversity seems to be extraordinary but may be represented by only a small number of the existing diversity of endosymbiotic prokaryotes in ciliates worldwide. In this chapter, we provide information about the history, diversity, and cytology of prokaryotic symbionts within the ciliates, as well as we describe some methods for the isolation, cultivation, and identification of these symbionts. Future research may broaden the knowledge presented here, to enhance our knowledge how these associations evolved, how they were established into permanent associations, and how they interact. and their interactions.Electronic supplementary material. Supplementary material is available in the online version of this article at (link) and is accessible for authorized users.}, author = {Schweikert, Michael and Fujishima, Masahiro and G\"ortz, Hans-Dieter}, booktitle = {The {{Prokaryotes}}}, doi = {10.1007/978-3-642-30194-0_18}, file = {/home/mike/Zotero/storage/MAIJQEBT/Schweikert et al. - 2013 - Symbiotic Associations Between Ciliates and Prokar.pdf;/home/mike/Zotero/storage/MHDQFXM8/10.html}, isbn = {978-3-642-30193-3 978-3-642-30194-0}, language = {en}, pages = {427-463}, publisher = {{Springer, Berlin, Heidelberg}}, title = {Symbiotic {{Associations Between Ciliates}} and {{Prokaryotes}}}, year = 2013 }
Schrallhammer, M., Galati, S., Altenbuchner, J., Schweikert, M., Görtz, H.-D., Petroni, G.: Tracing the Role of R-Bodies in the Killer Trait: Absence of Toxicity of R-Body Producing Recombinant E. Coli on Paramecia. European Journal of Protistology. 48, 290–296 (2012). https://doi.org/10.1016/j.ejop.2012.01.008.
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@article{Schrallhammer_EJoP_2012, abstract = {R-bodies are coiled proteinaceous ribbons produced by Paramecium endosymbionts belonging to the genus Caedibacter. These intracellular bacteria confer upon their hosts a phenomenon called the killer trait. It is the ability to kill symbiont-free competitors called sensitives. The R-body is the crucial element of this process, but despite many efforts, the actual role of R-bodies in killing sensitive paramecia is still not satisfactory clarified. The open question is whether the R-body acts as transmitter for a yet unidentified toxin or whether it directly kills sensitive paramecia having intrinsic cytotoxic effects. In the present study, this problem is addressed by heterologous expression of Caedibacter taeniospiralis R-body in Escherichia coli followed by a detailed analysis of its potential intrinsic toxic effect on feeding sensitive Paramecium tetraurelia. Using this approach, we can exclude any eventual effects of additional, unidentified factors produced by C. taeniospiralis and thus observe the impact of the recombinant R-body itself. No cytotoxic effects of recombinant R-bodies were detected following this approach, strengthening the hypothesis that R-bodies act as releasing system for an unidentified C. taeniospiralis toxin.}, author = {Schrallhammer, Martina and Galati, Stefano and Altenbuchner, Josef and Schweikert, Michael and G\"ortz, Hans-Dieter and Petroni, Giulio}, doi = {10.1016/j.ejop.2012.01.008}, file = {/home/mike/Zotero/storage/V6V8BQ35/Schrallhammer et al. - 2012 - Tracing the role of R-bodies in the killer trait .pdf;/home/mike/Zotero/storage/N2NYJ34I/S0932473912000193.html}, issn = {0932-4739}, journal = {European Journal of Protistology}, month = {11}, number = 4, pages = {290-296}, shorttitle = {Tracing the Role of {{R}}-Bodies in the Killer Trait}, title = {Tracing the Role of {{R}}-Bodies in the Killer Trait: {{Absence}} of Toxicity of {{R}}-Body Producing Recombinant {{E}}. Coli on Paramecia}, volume = 48, year = 2012 }
Godrijan, J., Marić, D., Imesek, M., Janeković, I., Schweikert, M., Pfannkuchen, M.: Diversity, Occurrence, and Habitats of the Diatom Genus Bacteriastrum (Bacillariophyta) in the Northern Adriatic Sea, with the Description of B. Jadranum Sp. Nov. Botanica Marina. 55, 415--426 (2012). https://doi.org/10.1515/bot-2011-0021.
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@article{Godrijan_BM_2012, abstract = {Ongoing phytoplankton monitoring programs over the last 12 years in the northern Adriatic Sea showed that the diatom genus Bacteriastrum is an important component of the pelagic diatom assemblage. The main goals of this study were to identify which Bacteriastrum species occur in the northern Adriatic Sea and describe their distributions. Bacteriastrum comosum and B. hyalinum f. princeps were rare, while B. delicatulum, B. hyalinum, and B. mediterraneum were frequently present, together with the newly proposed species B. jadranum, described herein. This new species is weakly silicified and is mainly characterized by a large aperture between each cell of the filament. Cells are connected to each other by 8\textendash{}12 setae, which cross at a distance equivalent to the diameters of 2\textendash{}3 cells. There is no difference in the orientation of the setae on the two terminal cells, hence the species is placed in the section Isomorpha. The new species was recorded throughout the study area, in both coastal and offshore waters, with higher cell abundances in the vicinity of the Po River during the September\textendash{}October period. The maximum cell abundance of B. jadranum was 244.2\texttimes{}103cells l-1in the surface waters at 44.75666667\textordmasculine{}N, 12.75\textordmasculine{}E in September 2006, sometimes representing up to 46\% of the entire phytoplankton assemblage, as recorded in the surface waters at 45.06833333\textordmasculine{}N, 13.515\textordmasculine{}E in October 2008.}, author = {Godrijan, Jelena and Mari\'c, Daniela and Ime{\v s}ek, Mirna and Janekovi\'c, Ivica and Schweikert, Michael and Pfannkuchen, Martin}, doi = {10.1515/bot-2011-0021}, file = {/home/mike/Zotero/storage/2DI9GVT4/Godrijan et al. - 2012 - Diversity, occurrence, and habitats of the diatom .pdf}, issn = {1437-4323}, journal = {Botanica Marina}, number = 4, pages = {415--426}, title = {Diversity, Occurrence, and Habitats of the Diatom Genus {{Bacteriastrum}} ({{Bacillariophyta}}) in the Northern {{Adriatic Sea}}, with the Description of {{B}}. Jadranum Sp. Nov.}, volume = 55, year = 2012 }
Gottschling, M., Soehner, S., Zinssmeister, C., John, U., Plötner, J., Schweikert, M., Aligizaki, K., Elbrächter, M.: Delimitation of the Thoracosphaeraceae (Dinophyceae), Including the Calcareous Dinoflagellates, Based on Large Amounts of Ribosomal RNA Sequence Data. Protist. 163, 15–24 (2012). https://doi.org/10.1016/j.protis.2011.06.003.
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@article{Gottschling_P_2012, abstract = {The phylogenetic relationships of the Dinophyceae (Alveolata) are not sufficiently resolved at present. The Thoracosphaeraceae (Peridiniales) are the only group of the Alveolata that include members with calcareous coccoid stages; this trait is considered apomorphic. Although the coccoid stage apparently is not calcareous, Bysmatrum has been assigned to the Thoracosphaeraceae based on thecal morphology. We tested the monophyly of the Thoracosphaeraceae using large sets of ribosomal RNA sequence data of the Alveolata including the Dinophyceae. Phylogenetic analyses were performed using Maximum Likelihood and Bayesian approaches. The Thoracosphaeraceae were monophyletic, but included also a number of non-calcareous dinophytes (such as Pentapharsodinium and Pfiesteria) and even parasites (such as Duboscquodinium and Tintinnophagus). Bysmatrum had an isolated and uncertain phylogenetic position outside the Thoracosphaeraceae. The phylogenetic relationships among calcareous dinophytes appear complex, and the assumption of the single origin of the potential to produce calcareous structures is challenged. The application of concatenated ribosomal RNA sequence data may prove promising for phylogenetic reconstructions of the Dinophyceae in future.}, author = {Gottschling, Marc and Soehner, Sylvia and Zinssmeister, Carmen and John, Uwe and Pl\"otner, J\"org and Schweikert, Michael and Aligizaki, Katerina and Elbr\"achter, Malte}, doi = {10.1016/j.protis.2011.06.003}, file = {/home/mike/Zotero/storage/JS2GUFLH/Gottschling et al. - 2012 - Delimitation of the Thoracosphaeraceae (Dinophycea.pdf;/home/mike/Zotero/storage/IVVI5ZAC/S1434461011000502.html}, issn = {1434-4610}, journal = {Protist}, month = {01}, number = 1, pages = {15-24}, title = {Delimitation of the {{Thoracosphaeraceae}} ({{Dinophyceae}}), {{Including}} the {{Calcareous Dinoflagellates}}, {{Based}} on {{Large Amounts}} of {{Ribosomal RNA Sequence Data}}}, volume = 163, year = 2012 }
Schrallhammer, M., Schweikert, M., Vallesi, A., Verni, F., Petroni, G.: Detection of a Novel Subspecies of Francisella Noatunensis as Endosymbiont of the Ciliate Euplotes Raikovi. Microbial Ecology. 61, 455–464 (2011). https://doi.org/10.1007/s00248-010-9772-9.
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@article{Schrallhammer_ME_2011, abstract = {Francisella are facultative intracellular bacteria causing severe disease in a broad range of animals. Two species are notable: Francisella tularensis, the causative organism of tularemia and a putative warfare agent, and Francisella noatunensis, an emerging fish pathogen causing significant losses in wild and farmed fish. Although various aspects of Francisella biology have been intensively studied, their natural reservoir in periods between massive outbreaks remains mysterious. Protists have been suspected to serve as a disguised vector of Francisella and co-culturing attempts demonstrate that some species are able to survive and multiply within protozoan cells. Here, we report the first finding of a natural occurrence of Francisella sp. as a protist endosymbiont. By molecular and morphological approaches, we identified intracellular bacteria localized in a strain of the marine ciliate Euplotes raikovi, isolated from the coast of Adriatic Sea. Phylogenetic analysis placed these endosymbionts within the genus Francisella, in close but distinct association with F. noatunensis. We suggest the establishment of a novel subspecies within F. noatunensis and propose the cytoplasmatic endosymbiont of E. raikovi as ``Candidatus F. noatunensis subsp. endociliophora'' subsp. nov.}, author = {Schrallhammer, Martina and Schweikert, Michael and Vallesi, Adriana and Verni, Franco and Petroni, Giulio}, doi = {10.1007/s00248-010-9772-9}, file = {/home/mike/Zotero/storage/Y4MNA8V6/Schrallhammer et al. - 2011 - Detection of a Novel Subspecies of Emphasis Type=.pdf;/home/mike/Zotero/storage/7IU7B2T5/s00248-010-9772-9.html}, issn = {0095-3628, 1432-184X}, journal = {Microbial Ecology}, language = {en}, month = {02}, number = 2, pages = {455-464}, title = {Detection of a {{Novel Subspecies}} of {{Francisella}} Noatunensis as {{Endosymbiont}} of the {{Ciliate}} {{Euplotes}} Raikovi}, volume = 61, year = 2011 }
Dunthorn, M., Eppinger, M., Schwarz, M.V.J., Schweikert, M., Boenigk, J., Katz, L.A., Stoeck, T.: Phylogenetic Placement of the Cyrtolophosididae Stokes, 1888 (Ciliophora; Colpodea) and Neotypification of Aristerostoma Marinum Kahl, 1931. International Journal of Systematic and Evolutionary Microbiology. 59, 167–180 (2009). https://doi.org/10.1099/ijs.0.000935-0.
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@article{Dunthorn_IJSEM_2009, abstract = {The ciliate family Cyrtolophosididae Stokes, 1888 contains species that are poorly known from both the morphological and molecular perspectives. To further our understanding of this family, one species, Aristerostoma marinum Kahl, 1931 , was redescribed. Cells in our population had a mean in vivo size of 15\texttimes{}8\hspace{0.25em}$\mu$m. There were six rows of somatic kineties, as well as six dorsal kinetids belonging to sparsely ciliated somatic kineties. The oral apparatus comprised a bipartite paroral membrane and four adoral organelles. The optimal ecological tolerances for pH and O2 matched those of the environment in which the specimens were collected, but were different for salinity and temperature. To further test the phylogenetic placement of the family Cyrtolophosididae with increased taxon sampling, the small subunit rDNA of three morphospecies was characterized: A. marinum, Aristerostoma sp. ATCC 50986 and Pseudocyrtolophopsis alpestris. Unconstrained and constrained molecular analyses supported the non-monophyly of the order Cyrtolophosidida. The family Cyrtolophosididae fell out separately from the rest of its order. Haplotypes from previous environmental studies were also placed in a phylogenetic context within the class Colpodea.}, author = {Dunthorn, Micah and Eppinger, Marion and Schwarz, M. V. Julian and Schweikert, Michael and Boenigk, Jens and Katz, Laura A. and Stoeck, Thorsten}, doi = {10.1099/ijs.0.000935-0}, file = {/home/mike/Zotero/storage/9Z9LHDVN/ijs.0.html}, journal = {International Journal of Systematic and Evolutionary Microbiology}, number = 1, pages = {167-180}, title = {Phylogenetic Placement of the {{Cyrtolophosididae Stokes}}, 1888 ({{Ciliophora}}; {{Colpodea}}) and Neotypification of {{Aristerostoma}} Marinum {{Kahl}}, 1931}, volume = 59, year = 2009 }
Schrallhammer, M., Schweikert, M.: The Killer Effect of Paramecium and Its Causative Agents. In: Endosymbionts in Paramecium. pp. 227–246. Springer, Berlin, Heidelberg (2009). https://doi.org/10.1007/978-3-540-92677-1_9.
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@incollection{Schrallhammer_EiP_2009, abstract = {Frequently, nonrelated organisms form endocytobioses resulting in organisms with different characters compared with those of the individual partners alone. Endocytic bacteria of the genus Caedibacter in host ciliates of the genus Paramecium enable their host to kill sensitive paramecia. These paramecia therefore are called ``killers'' and the phenomenon was named ``killer trait'' (Sonneborn in Proc. Am. Philos. Soc. 79:411\textendash{}434, 1938). In their natural environment these endocytic bacteria enable their hosts to outcompete uninfected forms (Kusch et al. in Protist 153:47\textendash{}58, 2002). Endocytobioses become more complex when the intracellular bacteria are infected with phages, such as in the three partner association Paramecium-Caedibacter-bacteriophage. Interaction of the different partners results in the formation of a proteinaceous intracellular structure called a ``refractile body'' (R-body) within the bacteria. Physiological tests demonstrated that R-bodies are a prerequisite for Caedibacter to confer the killer trait to their host, but they are not the toxin that kills sensitive paramecia (Preer et al. in Proc. Natl. Acad. Sci. USA 39:1228\textendash{}1233, 1953). In this chapter we focus on the Caedibacter species, with additional brief remarks on other endocytic killer bacteria and on R-bodies produced by free-living bacteria.}, author = {Schrallhammer, Martina and Schweikert, Michael}, booktitle = {Endosymbionts in {{Paramecium}}}, doi = {10.1007/978-3-540-92677-1_9}, file = {/home/mike/Zotero/storage/CR3CFYGS/978-3-540-92677-1_9.html}, isbn = {978-3-540-92676-4 978-3-540-92677-1}, language = {en}, pages = {227-246}, publisher = {{Springer, Berlin, Heidelberg}}, series = {Microbiology {{Monographs}}}, title = {The {{Killer Effect}} of {{Paramecium}} and {{Its Causative Agents}}}, year = 2009 }
Eschbach, E., Pfannkuchen, M., Schweikert, M., Drutschmann, D., Brümmer, F., Fokin, S., Ludwig, W., Görtz, H.-D.: ``Candidatus Paraholospora Nucleivisitans’’, an Intracellular Bacterium in Paramecium Sexaurelia Shuttles between the Cytoplasm and the Nucleus of Its Host. Systematic and Applied Microbiology. 32, 490–500 (2009). https://doi.org/10.1016/j.syapm.2009.07.004.
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@article{Eschbach_SaAM_2009, abstract = {An intracellular bacterium was discovered in two isolates of Paramecium sexaurelia from an aquarium with tropical fish in M\"unster (Germany) and from a pond in the Wilhelma zoological\textendash{}botanical garden, Stuttgart (Germany). The bacteria were regularly observed in the cytoplasm of the host, but on some occasions they were found in the macronucleus of the host cell. In these cases, only a few, if any, bacteria were observed remaining in the cytoplasm. The bacterium was not infectious to P. sexaurelia or other species of Paramecium and appeared to be an obligate intracellular bacterium, while bacteria-free host cells were completely viable. The fluorescence in situ hybridisation (FISH) and comparative 16SrDNA sequence analyses showed that the bacterium belonged to a new genus, and was most closely, yet quite distantly, related to Holospora obtusa. In spite of this relationship, the new bacteria differed from Holospora by at least two biological features. Whereas all Holospora species reside exclusively in the nuclei of various species of Paramecium and show a life cycle with a morphologically distinct infectious form, for the new bacterium no infectious form and no life cycle have been observed. For the new bacterium, the name Candidatus Paraholospora nucleivisitans is suggested. The host P. sexaurelia is usually known from tropical and subtropical areas and is not a species typically found in Germany and central Europe. Possibly, it had been taken to Germany with fish or plants from tropical or subtropical waters. Candidatus Paraholospora nucleivisitans may therefore be regarded as an intracellular neobacterium for Germany.}, author = {Eschbach, Erik and Pfannkuchen, Martin and Schweikert, Michael and Drutschmann, Denja and Br\"ummer, Franz and Fokin, Sergei and Ludwig, Wolfgang and G\"ortz, Hans-Dieter}, doi = {10.1016/j.syapm.2009.07.004}, file = {/home/mike/Zotero/storage/NBZJQXTU/Eschbach et al. - 2009 - “Candidatus Paraholospora nucleivisitans”, an intr.pdf;/home/mike/Zotero/storage/CZV4FB5B/S0723202009000897.html}, issn = {0723-2020}, journal = {Systematic and Applied Microbiology}, month = {10}, number = 7, pages = {490-500}, title = {``{{Candidatus Paraholospora}} Nucleivisitans'', an Intracellular Bacterium in {{Paramecium}} Sexaurelia Shuttles between the Cytoplasm and the Nucleus of Its Host}, volume = 32, year = 2009 }
Görtz, H.-D., Rosati, G., Schweikert, M., Schrallhammer, M., Omura, G., Suzaki, T.: Microbial Symbionts for Defense and Competition among Ciliate Hosts in: Defensive Mutualism in Microbial Symbiosis. (2009).
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@book{gortz2009microbial, author = {Görtz, Hans-Dieter and Rosati, Giovanna and Schweikert, Michael and Schrallhammer, Martina and Omura, Gen and Suzaki, Toshinobu}, editor = {White, James F. and Torres, Monica S.}, title = {Microbial Symbionts for Defense and Competition among Ciliate Hosts in: Defensive Mutualism in Microbial Symbiosis}, year = 2009 }
Sohn, K., Schwenk, J., Urban, C., Lechner, J., Schweikert, M., Rupp, S.: Getting in Touch with Candida Albicans: The Cell Wall of a Fungal Pathogen. Current Drug Targets. 7, 505–512 (2006). https://doi.org/10.2174/138945006776359395.
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@article{Sohn_CDT_2006, abstract = {The cell wall of fungi is a highly complex structure consisting of a network of polysaccharides in which a plethora of different proteins are embedded. It is one of the major organelles of the cell surrounding it like an armor which protects from environmental stresses like osmotic pressure and defines the shape and physical strength of the fungal cell. It is crucial for colonization and infection since it defines the interface between host and pathogen. No similar structure is present in the host, therefore it defines a prime target for drug development. In this context, it has been shown that cell surface proteins are required for adhesion to host cells. The fact, that both pathogenic fungi, like Candida albicans as well as non-pathogenic fungi, like Saccharomyces cerevisiae, in general, have a very similar polysaccharide structure but differ significantly in their protein composition which underscores the importance of cell wall proteins for pathogenesis. However, cell wall proteomics of fungi is a highly challenging task due to the complex biochemistry of these proteins. The extensive post-translational modifications and covalent attachment to the polysaccharide backbone of a large proportion of cell wall proteins makes it a demanding task to isolate and identify them. In this article, we describe the recent approaches that have been developed to describe cell wall dynamics and to isolate and identify cell wall proteins in the pathogenic yeast C. albicans.}, author = {Sohn, Kai and Schwenk, Jochen and Urban, Constantin and Lechner, Johannes and Schweikert, Michael and Rupp, Steffen}, doi = {10.2174/138945006776359395}, journal = {Current Drug Targets}, month = {04}, number = 4, pages = {505-512}, shorttitle = {Getting in {{Touch}} with {{Candida}} Albicans}, title = {Getting in {{Touch}} with {{Candida}} Albicans: {{The Cell Wall}} of a {{Fungal Pathogen}}}, volume = 7, year = 2006 }
Nickel, M., Donath, T., Schweikert, M., Beckmann, F.: Functional Morphology of Tethya Species (Porifera): 1. Quantitative 3D-Analysis of Tethya Wilhelma by Synchrotron Radiation Based X-Ray Microtomography. Zoomorphology. 125, 209–223 (2006). https://doi.org/10.1007/s00435-006-0021-1.
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@article{Nickel_Z_2006, abstract = {Rhythmic body contraction is a phenomenon in the Porifera, which is only partly understood. As a foundation for the understanding of the functional morphology of the highly contractile Tethya wilhelma, we performed a qualitative and quantitative volumetric 3D-analysis of the morphology of a complete non-contracted specimen at resolutions of 5.2 and 6.9 $\mu$m, using synchrotron radiation based X-ray computed microtomography (SR-$\mu$CT). For the first time, we were able to visualize all three major body structures of a complete poriferan without dissection of the shock-frozen, fixed and contrasted specimen in a near-to-life confirmation: poriferan tissue, mineral skeleton and aquiferous system. Applying a `virtual cast' technique allowed us to analyze the structural details of the complete canal structure. Our results imply an extensive re-circulation of water inside the poriferan due to well-developed by-pass-canals, connecting excurrent and incurrent system. Nevertheless, the oscule region is strictly separated from the incurrent system. Based on our data, we developed a hypothetical flow regime for T. wilhelma, which explains the necessity of by-pass canals to minimize pressure boosts in the canal system during contraction. Additionally, re-circulation optimizes nutrient uptake, within small-sized poriferans, like T. wilhelma. Quantitative analysis allowed us to measure volumes and surfaces, displaying remarkable organizational differences between choanosome and cortex, by means of distribution of morphological elements. The surface-to-volume ratio proved to be very high, underlining the importance of the poriferan pinacoderm. We support a pinacoderm-contraction hypothesis.}, author = {Nickel, Michael and Donath, Tilman and Schweikert, Michael and Beckmann, Felix}, doi = {10.1007/s00435-006-0021-1}, file = {/home/mike/Zotero/storage/5JSYIZMB/Nickel et al. - 2006 - Functional morphology of Tethya species (Porifera).pdf;/home/mike/Zotero/storage/R7ZIAJ7I/s00435-006-0021-1.html}, issn = {0720-213X, 1432-234X}, journal = {Zoomorphology}, language = {en}, month = {11}, number = 4, pages = {209-223}, shorttitle = {Functional Morphology of {{Tethya}} Species ({{Porifera}})}, title = {Functional Morphology of {{Tethya}} Species ({{Porifera}}): 1. {{Quantitative 3D}}-Analysis of {{Tethya}} Wilhelma by Synchrotron Radiation Based {{X}}-Ray Microtomography}, volume = 125, year = 2006 }
Collingro, A., Poppert, S., Heinz, E., Schmitz-Esser, S., Essig, A., Schweikert, M., Wagner, M., Horn, M.: Recovery of an Environmental Chlamydia Strain from Activated Sludge by Co-Cultivation with Acanthamoeba Sp. Microbiology (Reading, England). 151, 301–309 (2005). https://doi.org/10.1099/mic.0.27406-0.
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@article{Collingro_M(E_2005, abstract = {Chlamydiae are a unique group of obligate intracellular bacteria comprising important pathogens of vertebrates as well as symbionts of free-living amoebae. Although there is ample molecular evidence for a huge diversity and wide distribution of chlamydiae in nature, environmental chlamydiae are currently represented by only few isolates. This paper reports the recovery of a novel environmental chlamydia strain from activated sludge by co-cultivation with Acanthamoeba sp. The recovered environmental chlamydia strain UV-7 showed the characteristic morphology of chlamydial developmental stages as revealed by electron microscopy and was identified as a new member of the family Parachlamydiaceae (98.7 \% 16S rRNA sequence similarity to Parachlamydia acanthamoebae). Infection studies suggested that Parachlamydia sp. UV-7 is not confined to amoeba hosts but is also able to invade mammalian cells. These findings outline a new straightforward approach to retrieving environmental chlamydiae from nature without prior, tedious isolation and cultivation of their natural host cells, and lend further support to suggested implications of environmental chlamydiae for public health.}, author = {Collingro, Astrid and Poppert, Sven and Heinz, Eva and {Schmitz-Esser}, Stephan and Essig, Andreas and Schweikert, Michael and Wagner, Michael and Horn, Matthias}, doi = {10.1099/mic.0.27406-0}, issn = {1350-0872}, journal = {Microbiology (Reading, England)}, language = {eng}, month = {01}, number = {Pt 1}, pages = {301-309}, pmid = {15632447}, title = {Recovery of an Environmental {{Chlamydia}} Strain from Activated Sludge by Co-Cultivation with {{Acanthamoeba}} Sp}, volume = 151, year = 2005 }
Fokin, S., Schweikert, M., Brümmer, F., Görtz, H.-D.: Spirostomum Spp. (Ciliophora, Protista), a Suitable System for Endocytobiosis Research. Protoplasm. 225, 93–102 (2005). https://doi.org/10.1007/s00709-004-0078-y.
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@article{S__2005, abstract = {Abstract: Among ciliate genera, only Paramecium and Euplotes species have been studied extensively as host organisms of bacterial endocytobionts. In this article, we show that members of the genus Spirostomum may also serve as a suitable system for endocytobiosis research. Two strains of Spirostomum minus (Heterotrichea, Ciliophora) collected in Germany and Italy, respectively, were found to harbor different types of bacterial infections. Bacteria of various sizes and shapes were observed in the cytoplasm or in the nuclei of the ciliates. The bacteria in the cytoplasm were either surrounded by a peribacterial membrane or lay naked. One of the bacterial species was found in the vicinity of the contractile fibrillar system (myonemes) of the ciliates. In rare cases, another type of bacteria was observed associated with mitochondria. The macronuclei of both the Italian and the German strains were crowded with endocytobionts. The endonuclear bacteria in the two S. minus strains differed ..}, author = {Fokin, Sergei and Schweikert, Michael and Brümmer, Franz and Görtz, Hans-Dieter}, doi = {10.1007/s00709-004-0078-y}, file = {/home/mike/Zotero/storage/U5EBKNC8/54897472.html}, journal = {Protoplasm}, language = {en-gb}, month = {03}, number = {1-2}, pages = {93-102}, title = {Spirostomum Spp. (Ciliophora, Protista), a Suitable System for Endocytobiosis Research}, volume = 225, year = 2005 }
Kremp, A., Elbrächter, M., Schweikert, M., Wolny, J.L., Gottschling, M.: Woloszynskia Halophila (Biecheler) Comb. Nov.: A Bloom-Forming Cold-Water Dinoflagellate Co-Occurring with Scrippsiella Hangoei (Dinophyceae) in the Baltic Sea1. Journal of Phycology. 41, 629–642 (2005). https://doi.org/10.1111/j.1529-8817.2005.00070.x.
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@article{Kremp_JP_2005, abstract = {Molecular analyses and subsequent morphological reinvestigation of clonal isolates germinated from cysts previously assigned to Scrippsiella hangoei (Schiller) Larsen revealed considerable differences to vegetative cell isolates of this cold-water dinoflagellate from the northern Baltic Sea. The presence of hexagonal platelets on the cell surface and a characteristic acrobase on the episome agree with the description of Gymnodinium halophilum Biecheler. However, the arrangement of amphiesmal vesicles in more than nine latitudinal series indicates allocation of this dinoflagellate to Woloszynskia Thompson. We therefore reassign G. halophilum to Woloszynskia halophila. This species exhibits ultrastructural characteristics similar to Polarella glacialis Montresor et al. and symbiontic Gymnodinium Stein, such as stalked pyrenoids and a central eyespot consisting of multiple layers of crystal-filled vacuoles. A close relationship between these dinoflagellates is also supported by 28s rRNA sequence data. The preference for high salinities identifies W. halophila as a marine species. The spiny resting cysts of W. halophila are identical to the cysts formed during the massive encystment events previously attributed to S. hangoei in the Baltic Sea. This suggests that W. halophila is a significant contributor to the dinoflagellate spring blooms in the Baltic Sea. Scrippsiella hangoei clones, in turn, produce noncalcareous and smooth-walled cysts when crossed with a complementary mating type.}, author = {Kremp, Anke and Elbr\"achter, Malte and Schweikert, Michael and Wolny, Jennifer L. and Gottschling, Marc}, doi = {10.1111/j.1529-8817.2005.00070.x}, file = {/home/mike/Zotero/storage/ZICDNAXR/Kremp et al. - 2005 - Woloszynskia Halophila (biecheler) Comb. Nov. A B.pdf;/home/mike/Zotero/storage/VPPESQQF/abstract.html}, issn = {1529-8817}, journal = {Journal of Phycology}, language = {en}, month = {06}, number = 3, pages = {629-642}, shorttitle = {Woloszynskia {{Halophila}} (Biecheler) {{Comb}}. {{Nov}}.}, title = {Woloszynskia {{Halophila}} (Biecheler) {{Comb}}. {{Nov}}.: {{A Bloom}}-{{Forming Cold}}-{{Water Dinoflagellate Co}}-{{Occurring}} with {{Scrippsiella Hangoei}} (Dinophyceae) in the {{Baltic Sea1}}}, volume = 41, year = 2005 }
Stoeck, T., Schwarz, M.V.J., Boenigk, J., Schweikert, M., von der Heyden, S., Behnke, A.: Cellular Identity of an 18S rRNA Gene Sequence Clade within the Class Kinetoplastea: The Novel Genus Actuariola Gen. Nov. (Neobodonida) with Description of the Type Species Actuariola Framvarensis Sp. Nov. International Journal of Systematic and Evolutionary Microbiology. 55, 2623–2635 (2005). https://doi.org/10.1099/ijs.0.63769-0.
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@article{Stoeck_IJSEM_2005, abstract = {Environmental molecular surveys of microbial diversity have uncovered a vast number of novel taxonomic units in the eukaryotic tree of life that are exclusively known by their small-subunit (SSU) rRNA gene signatures. In this study, we reveal the cellular and taxonomic identity of a novel eukaryote SSU rRNA gene sequence clade within the Kinetoplastea. Kinetoplastea are ubiquitously distributed flagellated protists of high ecological and medical importance. We isolated an organism from the oxic\textendash{}anoxic interface of the anoxic Framvaren Fjord (Norway), which branches within an unidentified kinetoplastean sequence clade. Ultrastructural studies revealed a typical cellular organization that characterized the flagellated isolate as a member of the order Neobodonida Vickerman 2004, which contains five genera. The isolate differed in several distinctive characters from Dimastigella, Cruzella, Rhynchobodo and Rhynchomonas. The arrangement of the microtubular rod that supports the apical cytostome and the cytopharynx differed from the diagnosis of the fifth described genus (Neobodo Vickerman 2004) within the order Neobodonida. On the basis of both molecular and microscopical data, a novel genus within the order Neobodonida, Actuariola gen. nov., is proposed. Here, we characterize its type species, Actuariola framvarensis sp. nov., and provide an in situ tool to access the organism in nature and study its ecology.}, author = {Stoeck, Thorsten and Schwarz, M. V. Julian and Boenigk, Jens and Schweikert, Michael and {von der Heyden}, Sophie and Behnke, Anke}, doi = {10.1099/ijs.0.63769-0}, file = {/home/mike/Zotero/storage/T7AD6CWG/ijs.0.html}, journal = {International Journal of Systematic and Evolutionary Microbiology}, number = 6, pages = {2623-2635}, shorttitle = {Cellular Identity of an {{18S rRNA}} Gene Sequence Clade within the Class {{Kinetoplastea}}}, title = {Cellular Identity of an {{18S rRNA}} Gene Sequence Clade within the Class {{Kinetoplastea}}: The Novel Genus {{Actuariola}} Gen. Nov. ({{Neobodonida}}) with Description of the Type Species {{Actuariola}} Framvarensis Sp. Nov.}, volume = 55, year = 2005 }
Hoppenrath, M., Saldarriaga, J.F., Schweikert, M., Elbrächter, M., Taylor, F.J.R.: Description of Thecadinium Mucosum Sp. Nov. (Dinophyceae), a New Sand-Dwelling Marine Dinoflagellate, and an Emended Description of Thecadinium Inclinatum Balech1. Journal of Phycology. 40, 946–961 (2004). https://doi.org/10.1111/j.1529-8817.2004.03045.x.
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@article{Hoppenrath_JP_2004, abstract = {A new thecate, phototrophic, marine, sand-dwelling dinoflagellate, Thecadinium mucosum Hoppenrath et Taylor sp. nov., is described from a culture isolated from Boundary Bay, British Columbia, Canada. It was illustrated with LM as well as SEM and TEM, and its position in the phylogenetic tree of dinoflagellates was investigated using molecular methods. Cells are asymmetrical, oval, laterally flattened, and strongly pigmented, with the plate formula P 3${'}$ 1a 6${'}{'}$ 7/8c 5~s 6${'}{'}{'}$ 2${'}{'}{'}{'}$. Thecal plates are smooth with scattered pores, and there is a distinctive anterior intercalary plate that could be involved in mucus secretion. Thecadinium inclinatum Balech (=Sabulodinium inclinatum (Balech) Saunders et Dodge), a thecate, marine, sand-dwelling species that has been previously confused with what we now call T. mucosum, was also examined and illustrated through LM and SEM. New information on T. inclinatum is provided, including its plate formula P 3${'}$ 6${'}{'}$ 7c ?s 5${'}{'}{'}$ 1p 1${'}{'}{'}{'}$; we consider T. inclinatum to be related to most other Thecadinium species and not to Sabulodinium. Molecular phylogenetic analyses based on the small subunit ribosomal gene of T. mucosum, T. kofoidii (the type species of the genus), and T. dragescoi weakly support earlier suspicions based on morphology that T. dragescoi is not a member of Thecadinium. Tabulational patterns of the species suggest a relationship to the genus Amphidiniopsis.}, author = {Hoppenrath, Mona and Saldarriaga, Juan F. and Schweikert, Michael and Elbr\"achter, Malte and Taylor, F. J. R.}, doi = {10.1111/j.1529-8817.2004.03045.x}, file = {/home/mike/Zotero/storage/4I8MLZI6/Hoppenrath et al. - 2004 - Description of Thecadinium Mucosum Sp. Nov. (dinop.pdf;/home/mike/Zotero/storage/3GYMSQRH/abstract.html}, issn = {1529-8817}, journal = {Journal of Phycology}, language = {en}, month = {10}, number = 5, pages = {946-961}, title = {Description of {{Thecadinium Mucosum Sp}}. {{Nov}}. (Dinophyceae), a {{New Sand}}-{{Dwelling Marine Dinoflagellate}}, and an {{Emended Description}} of {{Thecadinium Inclinatum Balech1}}}, volume = 40, year = 2004 }
Schweikert, M., Elbrächter, M.: First Ultrastructural Investigations of the Consortium between a Phototrophic Eukaryotic Endocytobiont and Podolampas Bipes (Dinophyceae). Phycologia. 43, 614–623 (2004). https://doi.org/10.2216/i0031-8884-43-5-614.1.
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@article{Schweikert_P_2004, abstract = {Several species of the genus Podolampas (Dinophyceae), P. antarctica, P. bipes, P. elegans, P. palmipes, P. reliculata, P. spinifera and a new undescribed species, were recurrently found in plankton samples of the Atlantic Ocean, Pacific Ocean and the Mediterranean Sea during several oceanographic expeditions. Only P. bipes and P. reticulata always contained autofluorescent endocytobionts, which were interpreted as dinoflagellate chloroplasts by former investigations based on light microscopy. Our investigations of P. bipes showed a consortium of the dinoflagellate and multiple, endocytic cells, each containing chloroplasts, mitochondria, ribosomes, a dictyosome and a eukaryotic nucleus. In culture, these endocytobionts were persistent in the host cells and were distributed into both daughter cells during mitotic cell division. Although endo-symbionts are known from various dinoflagellates, endocytobiosis of several photosynthetic eukaryotic cells per dinoflagellate is new. Ultrastructural details of the endocytobionts show that they belong to the class Dictyochophyceae (Heterokontophyta), most probably to the order Pedinellales. Additionally, further ultrastructural details of P. bipes, such as the presence of three types of extrusomes, intracellular bacteria, rod-like structures composed of tubules and a presumably motile thecal plate, are described.}, author = {Schweikert, Michael and Elbr\"achter, Malte}, doi = {10.2216/i0031-8884-43-5-614.1}, file = {/home/mike/Zotero/storage/ZJ5V3EZI/i0031-8884-43-5-614.html}, issn = {0031-8884}, journal = {Phycologia}, month = {09}, number = 5, pages = {614-623}, title = {First Ultrastructural Investigations of the Consortium between a Phototrophic Eukaryotic Endocytobiont and {{Podolampas}} Bipes ({{Dinophyceae}})}, volume = 43, year = 2004 }
Fokin, S.O., Skovorodkin, I.N., Schweikert, M., Görtz, H.-D.: Co-Infection of the Macronucleus of Paramecium Caudatum by Free-Living Bacteria Together with the Infectious Holospora Obtusa. Journal of Eukaryotic Microbiology. 51, 417–424 (2004). https://doi.org/10.1111/j.1550-7408.2004.tb00388.x.
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@article{Fokin_JEM_2004, abstract = {Infection experiments were performed incubating Paramecium caudatum with non-infectious free-living bacteria or weakly infectious intracellular bacteria together with the infectious Holospora obtusa. Two of four non-infectious free-living bacteria (Enterobacter aerogenes and Klebsiella pneumoniae) were found to get into the nuclei when added to Paramecium together with H. obtusa. The endonuclear bacterium Nonospora macronucleata that is weakly infectious by itself increases its infectivity when presented together with the infectious holosporas. The results provide evidence that H. obtusa may facilitate entry of other, non-infectious bacteria into the nuclei of Paramecium.}, author = {Fokin, Sergei O. and Skovorodkin, Ilya N. and Schweikert, Michael and G\"ortz, Hans-D.}, doi = {10.1111/j.1550-7408.2004.tb00388.x}, file = {/home/mike/Zotero/storage/X4NVTX3M/Fokin et al. - 2004 - Co-infection of the Macronucleus of Paramecium cau.pdf;/home/mike/Zotero/storage/GP7G5N8D/abstract.html}, issn = {1550-7408}, journal = {Journal of Eukaryotic Microbiology}, language = {en}, month = {07}, number = 4, pages = {417-424}, title = {Co-Infection of the {{Macronucleus}} of {{Paramecium}} Caudatum by {{Free}}-{{Living Bacteria Together}} with the {{Infectious Holospora}} Obtusa}, volume = 51, year = 2004 }
Hoppenrath, M., Schweikert, M., Elbrächter, M.: Morphological Reinvestigation and Characterization of the Marine, Sand-Dwelling Dinoflagellate Adenoides Eludens (Dinophyceae). European Journal of Phycology. 38, 385–394 (2003). https://doi.org/10.1080/09670260310001613717.
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@article{Hoppenrath_EJP_2003, abstract = {The phototrophic, marine, sand-dwelling dinoflagellate Adenoides eludens (Herdman) Balech was isolated from intertidal sand of the North German Wadden Sea and subsequently cultured. For taxonomic purposes it was examined using light, scanning and transmission electron microscopy. Cells are slightly asymmetrical, oval to round, laterally flattened, 30.0 \textendash{} 35.0 $\mu$m long and 23.0 \textendash{} 28.0 $\mu$m deep. The theca is composed of 26 plates. According to our interpretation the plate formula is Po 4${'}$ 6c 4s 5${'}{'}{'}$ 5p 1${'}{'}{'}{'}$ or alternatively it can be interpreted as Po 4${'}$ 6c 5s 5${'}{'}{'}$ 3p 2${'}{'}{'}{'}$. All thecal plates are smooth with scattered pores. Dinoflagellate chloroplasts surrounded by three membranes display thylakoids grouped in stacks of three. Two stalked pyrenoids with a starch sheath are present. Spindle trichocysts were present and extruded through trichocyst pores. Additionally, intracellular gram-negative bacteria were found in the cytoplasm. Asexual reproduction is by desmoschisis. The position of Adenoides among the dinoflagellates is discussed, and we tentatively regard it as belonging to the gonyaulacoid lineage.}, author = {Hoppenrath, Mona and Schweikert, MichaeL and Elbr\"achter, Malte}, doi = {10.1080/09670260310001613717}, file = {/home/mike/Zotero/storage/ZBBDK6PT/Hoppenrath et al. - 2003 - Morphological reinvestigation and characterization.pdf;/home/mike/Zotero/storage/IP8NGNYW/09670260310001613717.html}, issn = {0967-0262}, journal = {European Journal of Phycology}, month = {11}, number = 4, pages = {385-394}, title = {Morphological Reinvestigation and Characterization of the Marine, Sand-Dwelling Dinoflagellate {{Adenoides}} Eludens ({{Dinophyceae}})}, volume = 38, year = 2003 }
Reinhard, C., Schweikert, M., Wieland, F.T., Nickel, W.: Functional Reconstitution of COPI Coat Assembly and Disassembly Using Chemically Defined Components. Proceedings of the National Academy of Sciences of the United States of America. 100, 8253–8257 (2003). https://doi.org/doi: 10.1073/pnas.1432391100.
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@article{Reinhard_P_2003, abstract = {Coat protein I (COPI)-coated transport vesicles mediate protein and lipid transport in the early secretory pathway. The basic machinery required for the formation of these transport intermediates has been elucidated based on the reconstitution of COPI-coated vesicle formation from chemically defined liposomes. In this experimental system, the coat components coatomer and GTP-bound ADP-ribosylation factor (ARF), as well as p23 as a membrane-bound receptor for COPI coat proteins, were shown to be both necessary and sufficient to promote COPI-coated vesicle formation. Based on biochemical and ultrastructural analyses, we now demonstrate that the catalytic domain of ARF-GTPase-activating protein (GAP) alone is sufficient to initiate uncoating of liposome-derived COPI-coated vesicles. By contrast, ARF-GAP activity is not required for COPI coat assembly and, therefore, does not seem to represent an essential coat component of COPI vesicles as suggested recently [Yang, J. S., Lee, S. Y., Gao, M., Bourgoin, S., Randazzo, P. A., et al. (2002) J. Cell Biol. 159, 69\textendash{}78]. Thus, a complete round of COPI coat assembly and disassembly has been reconstituted with purified components defining the core machinery of COPI vesicle biogenesis.}, author = {Reinhard, Constanze and Schweikert, Michael and Wieland, Felix T. and Nickel, Walter}, doi = {doi: 10.1073/pnas.1432391100}, file = {/home/mike/Zotero/storage/PYPW9MSG/8253.html}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, month = {07}, number = 14, pages = {8253-8257}, title = {Functional Reconstitution of {{COPI}} Coat Assembly and Disassembly Using Chemically Defined Components}, volume = 100, year = 2003 }
Fokin, S.I., Schweikert, M., Görtz, H.-D., Fujishima, M.: Bacterial Endocytobionts of Ciliophora. Diversity and Some Interactions with the Host. European Journal of Protistology. 39, 475–480 (2003). https://doi.org/10.1078/0932-4739-00023.
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@article{Fokin_EJoP_2003, abstract = {Some new cytoplasmic and mitochondrial (Spirostomum minus) as well as macronuclear bacteria (S. ambiguum) are recorded. The ciliate-bacteria system has high potential for investigations of endocytobiosis. New data are shown concerning antibacterial resistance of stocks of Paramecium caudatum. The results support a suggestion about food selection in this ciliate. Some possible ways of experimentally increasing the diversity of endonuclear bacteria in P. multimicronucleatum were demonstrated.}, author = {Fokin, Sergei I. and Schweikert, Michael and G\"ortz, Hans-Dieter and Fujishima, Masahiro}, doi = {10.1078/0932-4739-00023}, file = {/home/mike/Zotero/storage/HAZV7ASA/Fokin et al. - 2003 - Bacterial endocytobionts of Ciliophora. Diversity .pdf;/home/mike/Zotero/storage/URYYZJQ5/S0932473904701297.html}, issn = {0932-4739}, journal = {European Journal of Protistology}, month = {01}, number = 4, pages = {475-480}, title = {Bacterial Endocytobionts of {{Ciliophora}}. {{Diversity}} and Some Interactions with the Host}, volume = 39, year = 2003 }
Schweikert, M.: Cell Wall Ultrastructure and Intracytoplasmic Bacteria in Hypnocysts of Toxic Alexandrium Tamarense (Dinophyceae). (2003).
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@book{Schweikert__2003, abstract = {Summary Hypnocysts of toxic Alexandrium tamarense (Lebour) Balech collected during a bloom in the North Sea near Scotland (UK) have been investigated ultrastructurally. Details of cell wall morphology and a cell wall covering, not mentioned previously in the literature, are given. The presence of intracellular bacteria has been shown by means of transmission electron microscopy. These bacteria were present in early and mature hypnocysts, but absent in flagellated vegetative cells found in the same region. The evidence for the transmission of toxic bacteria via hypnocysts and their inoculation into the environment by excysted dinoflagellates is discussed.}, author = {Schweikert, Michael}, month = {01}, title = {Cell Wall Ultrastructure and Intracytoplasmic Bacteria in Hypnocysts of Toxic {{Alexandrium}} Tamarense ({{Dinophyceae}})}, volume = 3, year = 2003 }
Beier, C.L., Horn, M., Michel, R., Schweikert, M., Görtz, H.-D., Wagner, M.: The Genus Caedibacter Comprises Endosymbionts of Paramecium Spp. Related to the Rickettsiales (Alphaproteobacteria) and to Francisella Tularensis (Gammaproteobacteria). Applied and Environmental Microbiology. 68, 6043–6050 (2002). https://doi.org/10.1128/AEM.68.12.6043-6050.2002.
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@article{Beier_AEM_2002, abstract = {Obligate bacterial endosymbionts of paramecia able to form refractile inclusion bodies (R bodies), thereby conferring a killer trait upon their ciliate hosts, have traditionally been grouped into the genus Caedibacter. Of the six species described to date, only the Paramecium caudatum symbiont Caedibacter caryophilus has been phylogenetically characterized by its 16S rRNA gene sequence, and it was found to be a member of the Alphaproteobacteria related to the Rickettsiales. In this study, the Caedibacter taeniospiralis type strain, an R-body-producing cytoplasmatic symbiont of Paramecium tetraurelia strain 51k, was investigated by comparative 16S rRNA sequence analysis and fluorescence in situ hybridization with specific oligonucleotide probes. C. taeniospiralis is not closely related to C. caryophilus (80\% 16S rRNA sequence similarity) but forms a novel evolutionary lineage within the Gammaproteobacteria with the family Francisellaceae as a sister group (87\% 16S rRNA sequence similarity). These findings demonstrate that the genus Caedibacter is polyphyletic and comprises at least two phylogenetically different bacterial species belonging to two different classes of the Proteobacteria. Comparative phylogenetic analysis of C. caryophilus, five closely related Acanthamoeba endosymbionts (including one previously uncharacterized amoebal symbiont identified in this study), and their hosts suggests that the progenitor of the alphaproteobacterial C. caryophilus lived within acanthamoebae prior to the infection of paramecia.}, author = {Beier, Cora L. and Horn, Matthias and Michel, Rolf and Schweikert, Michael and G\"ortz, Hans-Dieter and Wagner, Michael}, doi = {10.1128/AEM.68.12.6043-6050.2002}, file = {/home/mike/Zotero/storage/JI27CX52/Beier et al. - 2002 - The Genus Caedibacter Comprises Endosymbionts of P.pdf;/home/mike/Zotero/storage/3CE2S99W/6043.html}, issn = {0099-2240, 1098-5336}, journal = {Applied and Environmental Microbiology}, language = {en}, month = {01}, number = 12, pages = {6043-6050}, pmid = {12450827}, title = {The {{Genus Caedibacter Comprises Endosymbionts}} of {{Paramecium}} Spp. {{Related}} to the {{Rickettsiales}} ({{Alphaproteobacteria}}) and to {{Francisella}} Tularensis ({{Gammaproteobacteria}})}, volume = 68, year = 2002 }
Fokin, S.I., Sabaneyeva, E.V., Borkhsenious, O.N., Schweikert, M., Görtz, H.-D.: Paramecium Calkinsi AndP. Putrinum (Ciliophora, Protista) Harboring Alpha-Subgroup Bacteria in the Cytoplasm. Protoplasma. 213, 176–183 (2000). https://doi.org/10.1007/BF01282155.
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@article{Fokin_P_2000, abstract = {SummaryNew intracellular bacteria were detected in the cytoplasm ofParamecium calkinsi andP. putrinum. Some of the bacteria were not evenly distributed in the cytoplasm of the host but were found in the center of the cell, eventually near the nuclei, but not in the cortex area, whereas another species was found in the cortex area. These peculiarities of intracellular bacteria localization in the host suggest that the conditions in various parts of the cytoplasm favor bacterial maintenance to different extent. Due to the results obtained by transmission electron microscopy and in situ hybridization using appropriate oligonucleotide probes, the bacteria, three or possibly four species, are Gram-negative and belong to the alpha-subgroup of proteobacteria. Bacteria from one stock ofP. calkinsi were found to be infectious for bacteria-free cells ofP. calkinsi andP. nephridiatum.}, author = {Fokin, S. I. and Sabaneyeva, E. V. and Borkhsenious, O. N. and Schweikert, M. and G\"ortz, H.-D.}, doi = {10.1007/BF01282155}, file = {/home/mike/Zotero/storage/H3TUYXTY/Fokin et al. - 2000 - Emphasis Type=ItalicParamecium calkinsiEmpha.pdf;/home/mike/Zotero/storage/MLIB5YF8/paramecium-calkinsi-and-p-putrinum-ciliophora-protista-harboring-alpha-0i44zkq9Zi.html;/home/mike/Zotero/storage/ZA2H3XHY/BF01282155.html}, issn = {0033-183X, 1615-6102}, journal = {Protoplasma}, language = {en}, month = {09}, number = {3-4}, pages = {176-183}, title = {Paramecium Calkinsi And{{P}}. Putrinum ({{Ciliophora}}, {{Protista}}) Harboring Alpha-Subgroup Bacteria in the Cytoplasm}, volume = 213, year = 2000 }
Bremser, M., Nickel, W., Schweikert, M., Ravazzola, M., Amherdt, M., Hughes, C.A., Söllner, T.H., Rothman, J.E., Wieland, F.T.: Coupling of Coat Assembly and Vesicle Budding to Packaging of Putative Cargo Receptors. Cell. 96, 495–506 (1999). https://doi.org/10.1016/S0092-8674(00)80654-6.
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@article{Bremser_C_1999, author = {Bremser, Martina and Nickel, Walter and Schweikert, Michael and Ravazzola, Mariella and Amherdt, Myl\`ene and Hughes, Christine A. and S\"ollner, Thomas H. and Rothman, James E. and Wieland, Felix T.}, doi = {10.1016/S0092-8674(00)80654-6}, file = {/home/mike/Zotero/storage/N97LEEF8/Bremser et al. - 1999 - Coupling of Coat Assembly and Vesicle Budding to P.pdf;/home/mike/Zotero/storage/ADCE8XKH/S0092-8674(00)80654-6.html}, issn = {0092-8674, 1097-4172}, journal = {Cell}, language = {English}, month = {02}, number = 4, pages = {495-506}, pmid = {10052452}, title = {Coupling of {{Coat Assembly}} and {{Vesicle Budding}} to {{Packaging}} of {{Putative Cargo Receptors}}}, volume = 96, year = 1999 }
Schweikert, M., Schnepf, E.: Pseudaphelidium drebesii, gen. et spec. nov. (incerta sedis), a parasite ofthe centric diatom Thalassiosira punctigera. Archiv für Protistenkunde. 147, 11–17 (1997).
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@article{schweikert1997pseudaphelidium, author = {Schweikert, Michael and Schnepf, Eberhard}, journal = {Archiv für Protistenkunde}, pages = {11-17}, title = {Pseudaphelidium drebesii, gen. et spec. nov. (incerta sedis), a parasite ofthe centric diatom Thalassiosira punctigera.}, volume = 147, year = 1997 }
Schweikert, M., Schnepf, E.: Electron Microscopical Observations on Pseudaphelidium drebesii Schweikert and Schnepf, a Parasite of the Centric DiatomThalassiosira Punctigera. Protoplasma. 199, 113–123 (1997). https://doi.org/10.1007/BF01294500.
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@article{Schweikert_P_1997, abstract = {SummaryUltrastructural observations revealed details of the infection process and the fine structure ofPseudaphelidium drebesii Schweikert and Schnepf, a parasite of the marine centric diatomThalassiosira punctigera (Castracane) Hasle. After attachment and encystment of the zoospore an intracellular infection tube is generated. This structure is everted between the overlap of the girdle bands or the gap between the valve and the girdle band of the host diatom. The bulk of thePseudaphelidium protoplast enters the silica shell of the diatom via the infection tube but does not pierce the host plasma membrane. Parts of the host cytoplasm are phagocytized with microfilament involvement.Pseudaphelidium drebesii is characterized by unusual microbodies containing tubular inclusions and by closed mitosis with a perinuclear spindle. The taxonomic position ofP. drebesii is discussed.}, author = {Schweikert, M. and Schnepf, E.}, doi = {10.1007/BF01294500}, file = {/home/mike/Zotero/storage/2VS33QWU/Schweikert and Schnepf - 1997 - Electron microscopical observations onEmphasis Ty.pdf;/home/mike/Zotero/storage/R9SD8DLF/BF01294500.html}, issn = {0033-183X, 1615-6102}, journal = {Protoplasma}, language = {en}, month = {09}, number = {3-4}, pages = {113-123}, title = {Electron Microscopical Observations on {{Pseudaphelidium}} drebesii {{Schweikert}} and {{Schnepf}}, a Parasite of the Centric Diatom{{Thalassiosira}} Punctigera}, volume = 199, year = 1997 }
Schnepf, E., Schweikert, M.: Pirsonia, Phagotrophic Nanoflagellates Incertae Sedis, Feeding on Marine Diatoms: Attachment, Fine Structure and Taxonomy. Archiv für Protistenkunde. 147, 361–371 (1997). https://doi.org/10.1016/S0003-9365(97)80060-7.
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@article{Schnepf_AfP_1997, abstract = {Summary After being chemotactically attracted by its host, marine diatoms of the genus Coscinodiscus, the Pirsonia flagellates are guided by the topography of the host cell surface to the rimoportulae through which the trophosome, a basally formed pseudopodium, penetrates into the diatom. Cytochalasin D does not disturb the chemotaxis of the flagellates but inhibits their attachment. Pirsonia diadema and P. guinardiae, feeding on Coscinodiscus and on Guinardia flaccida, respectively, are very similar in their fine structure. The anterior flagellum has tubular hairs which seem to belong to the tripartite, stramenopile type. They are synthesized within the ER and exocytosed by the Golgi apparatus. In certain developmental stages the posterior flagellum and the cell body bear ,,knotted hairs`` which differ in length. The mode of their formation is unknown. The mitochondria have unique non-contorted tubular cristae which are parallel to each other. The few dictyosomes have a parabasal position. The flagellar root apparatus consists of fibrillar bands which connect the basal body of the anterior flagellum with the nucleus and with the basal body of the posterior flagellum. Other fibrillar bands and a few microtubules run from the basal bodies to the cell surface. The organization of the flagellar root apparatus thus differs from that of typical stramenopiles. The taxonomic position of Pirsonia is discussed.}, author = {Schnepf, Eberhard and Schweikert, Michael}, doi = {10.1016/S0003-9365(97)80060-7}, file = {/home/mike/Zotero/storage/A89YDWN2/Schnepf and Schweikert - 1997 - Pirsonia, phagotrophic nanoflagellates incertae se.pdf;/home/mike/Zotero/storage/PFIZ568X/S0003936597800607.html}, issn = {0003-9365}, journal = {Archiv f\"ur Protistenkunde}, month = {04}, number = 3, pages = {361-371}, shorttitle = {Pirsonia, Phagotrophic Nanoflagellates Incertae Sedis, Feeding on Marine Diatoms}, title = {Pirsonia, Phagotrophic Nanoflagellates Incertae Sedis, Feeding on Marine Diatoms: Attachment, Fine Structure and Taxonomy}, volume = 147, year = 1997 }
Schweikert, M., Schnepf, E.: Pseudaphelidium Drebesii, Genet Specnov(Incerta Sedis), a Parasite of the Marine Centric Diatom Thalassiosira Punctigera. Archiv für Protistenkunde. 147, 11–17 (1996). https://doi.org/10.1016/S0003-9365(96)80004-2.
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@article{Schweikert_AfP_1996, abstract = {Summary: Pseudaphelidium drebesii genet specnovis a parasite of the centric marine diatom Thalassiosira punctigeraThe motile stage consists of a zoospore with a single opisthokont flagellumIt attaches to a host cell, encysts, penetrates the frustule and develops into a plasmodiumThe plasmodium phagocytizes portions of host cytoplasm which are included in a single big digestion vacuoleAt the end of the trophic phase the plasmodium is a hollow sphere filling the frustule completelyIt cleaves to form ameboid cells which are slowly motile and finally encystThe cysts release 4, sometimes less, zoosporesDiagnoses of genus and species are given, and the uncertain taxonomic position of Pseudaphelidium is discussed.}, author = {Schweikert, Michael and Schnepf, Eberhard}, doi = {10.1016/S0003-9365(96)80004-2}, file = {/home/mike/Zotero/storage/6FMBU6UV/Schweikert and Schnepf - 1996 - Pseudaphelidium drebesii, genet specnov(incerta se.pdf;/home/mike/Zotero/storage/SPRRMWEZ/S0003936596800042.html}, issn = {0003-9365}, journal = {Archiv f\"ur Protistenkunde}, month = {05}, number = 1, pages = {11-17}, title = {Pseudaphelidium Drebesii, Genet Specnov(Incerta Sedis), a {{Parasite}} of the {{Marine Centric Diatom Thalassiosira}} Punctigera}, volume = 147, year = 1996 }

Lebenslauf

Wissenschaftlicher Werdegang:
seit 2023	Akademischer Direktor an der Universität Stuttgart, IBBS, Abteilung Biobasierte Materialien
2007-2023	Akademischer Oberrat an der Universität Stuttgart, Biologisches Institut, Abteilung Zoologie
2006	Habilitation im Fach Zoologie an der Universität Stuttgart
2005-2007	Akademischer Rat an der Universität Stuttgart, Biologisches Institut, Abteilung Zoologie
2001	Wissenschaftlicher Assistent an der Universität Stuttgart, Biologisches Institut, Abteilung Zoologie
1998	Wissenschaftlicher Angestellter an der Universität Stuttgart im Projekt TEPS (Toxische Eukaryonten-Prokaryonten Systeme), Teilprojekt PABS
1998	Freier wissenschaftlicher Mitarbeiter am Biochemie Zentrum Heidelberg der Ruprecht-Karls-Universität Heidelberg
1995-1997	Promotion in der Zellenlehre der Ruprecht Karls-Universität Heidelberg
1989-1995	Studium im Fach Biologie mit Abschluss Diplom an der Ruprecht Karls-Universität Heidelberg

Expeditionen:
2000	Expedition mit dem Forschungsschiff "METEOR" vor Namibia (Westafrika)
2000	Expedition mit dem Forschungsschiff "HEINKE" im Rahmen des TEPS, Orkneys (Schottland)
1998	Expedition mit dem Forschungsschiff "HEINKE" im Rahmen des TEPS, Orkneys (Schottland)
1996	Expedition mit dem Forschunsschiff "SONNE" im Rahmen des TROPAC in Mikronesien (Südsee)
1993	Wissenschafliche Leitung des Entwicklungshilfeprojekts: Projet d´intensification Agro - Silvo - Pastorale (PIASP) in Rwanda (Ostafrika)

Michael Schweikert

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