Publications (28)111.01 Total impact
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Article: A New Tetrahymena (Ciliophora, Oligohymenophorea) from Groundwater of Cape Town, South Africa.
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ABSTRACT: The identification of species within the genus Tetrahymena is known to be difficult due to their essentially identical morphology, the occurrence of cryptic and sibling species and the phenotypic plasticity associated with the polymorphic life cycle of some species. We have combined morphology and molecular biology to describe Tetrahymena aquasubterranea n. sp. from groundwater of Cape Town, Republic of South Africa. The phylogenetic analysis compares the cox1 gene sequence of T. aquasubterranea with the cox1 gene sequences of other Tetrahymena species and uses the interior-branch test to improve the resolution of the evolutionary relationships. This showed a considerable genetic divergence of T. aquasubterranea to its next relative, T. farlyi, of 9.2% (the average cox1 divergence among bona fide species of Tetrahymena is ~ 10%). Moreover, the analysis also suggested a sister relationship between T. aquasubterranea and a big clade comprising T. farleyi, T. tropicalis, T. furgasoni and T. mobilis. The morphological data available for these species show that they share with T. aquasubterranea a pyriformis-like life style and at least two of them, T. farleyi and T. mobilis, a similar type II silverline pattern consisting of primary and secondary meridians. Tetrahymena aquasubterranea exhibits a biphasic life cycle with trophonts and theronts, is amicronucleate, and feeds on bacteria.Journal of Eukaryotic Microbiology 01/2013; · 2.66 Impact Factor -
Article: Different types of synchrony in chaotic and cyclic communities.
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ABSTRACT: Stability and persistence of populations is of great interest for management and conservation purposes. Spatial dynamics can have a crucial role in population stability via synchronization, and beneficial and detrimental effects on population persistence have been shown. Despite a theoretical understanding of synchronization, empirical data on synchrony of populations are restricted to systems that do not display the full spectrum of complex dynamics that may occur in nature (that is, chaos or quasiperiodicity). Here we show in experiments that the qualitative form of dynamic behaviour of chaotic and periodic oscillating communities did not change when unidirectionally coupled to oscillating driver communities. Driver and response populations were phase locked in cyclic communities, whereas chaotic communities showed only short periods of statistical coherencies. Our study provides the first empirical analysis of synchronization of chaotic communities and shows that the likelihood for chaos is not lowered in spatially explicit systems but that cyclic and chaotic systems differ in synchronization.Nature Communications 01/2013; 4:1359. · 7.40 Impact Factor -
Article: Quantification of individual flagellate - bacteria interactions within semi-natural biofilms.
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ABSTRACT: Here we present a new approach to quantify food-web interactions within semi-natural biofilms by combining the establishment of biofilms from natural rivers in flow cells with video microscopy. In a first application of this approach, we focused on the surface-gliding heterotrophic flagellates (HF) Neobodo designis, Rhynchomonas nasuta and Planomonas sp. It was shown that the three HF generally ingested single biofilm-associated bacteria whereas bacteria within microcolonies were attacked but not ingested. However, grazing strategies differed considerably. While the kinetoplastids N. designis and R. nasuta displayed long search and short handling times, Planomonas sp. showed the opposite grazing characteristics. The latter behaviour resulted in a high relative predation success of 80% (precent of attacked prey ingested), whereas the relative predation success of the two kinetoplastids was only 20%. However, the two contrasting strategies resulted in similar ingestion rates for Planomonas sp. and N. designis of 0.5 to 0.6 ingestions flagellates(-1) minute(-1), respectively. Our results showed distinct differences in the feeding behaviour of three flagellates having similar life forms and provide direct evidence that microcolony formation in biofilms protects bacteria from grazing by HF in situ. The new approach provides individual-based insights into the complex food web interactions within biofilms.Protist 12/2011; 163(4):632-42. · 3.14 Impact Factor -
Article: Analysis of the community structure of abyssal kinetoplastids revealed similar communities at larger spatial scales.
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ABSTRACT: Knowledge of the spatial scales of diversity is necessary to evaluate the mechanisms driving biodiversity and biogeography in the vast but poorly understood deep sea. The community structure of kinetoplastids, an important group of microbial eukaryotes belonging to the Euglenozoa, from all abyssal plains of the South Atlantic and two areas of the eastern Mediterranean was studied using partial small subunit ribosomal DNA gene clone libraries. A total of 1364 clones from 10 different regions were retrieved. The analysis revealed statistically not distinguishable communities from both the South-East Atlantic (Angola and Guinea Basin) and the South-West Atlantic (Angola and Brazil Basin) at spatial scales of 1000-3000 km, whereas all other communities were significantly differentiated from one another. It seems likely that multiple processes operate at the same time to shape communities of deep-sea kinetoplastids. Nevertheless, constant and homogenous environmental conditions over large spatial scales at abyssal depths, together with high dispersal capabilities of microbial eukaryotes, maintain best the results of statistically indistinguishable communities at larger spatial scales.The ISME Journal 11/2011; 6(4):713-23. · 7.38 Impact Factor -
Article: Higher level taxonomy and molecular phylogenetics of the Choanoflagellatea.
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ABSTRACT: The choanoflagellates (Choanoflagellatea) comprise a major group of nanoflagellates, which are ubiquitous in the aquatic environment. Recent molecular phylogenies have shown them to be the sister group to the Metazoa. However, the phylogeny of the choanoflagellates is still far from understood. We present here a 29 taxon, multigene phylogeny that robustly places the root of the choanoflagellates. One of the original nonloricate families, Codonosigidae is shown to be a polyphyletic assemblage nested within the Salpingoecidae. We elaborate on a revised taxonomy that divides Choanoflagellatea into two orders: Craspedida and Acanthoecida. Craspedida is composed of species that possess an organic cell coating and contains the single family Salpingoecidae. Members of the predominantly marine Acanthoecida produce a siliceous lorica in addition to an organic coat and are contained in two families--the Acanthoecidae and Stephanoecidae fam. n. Previous studies of choanoflagellates have been hindered by cases of taxon misidentification as well as the limited resolution of 18S small subunit (SSU) rDNA phylogenies. Unfortunately, cases of misidentification have been heavily repeated in the literature. In an attempt to avoid further confusion, we highlight known instances of misnamed taxa. We also examine the suitability of SSU rDNA sequences alone for choanoflagellate phylogenetics and recommend the use of protein-coding genes, such as hsp90 and tubA, whenever possible.Journal of Eukaryotic Microbiology 09/2011; 58(5):452-62. · 2.66 Impact Factor -
Article: WITHDRAWN: Wide distribution ranges of several microbial eukaryotes of nanofaunal size at abyssal depths of the South-East Atlantic and the Mediterranean.
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ABSTRACT: This article has been withdrawn.Applied and environmental microbiology 02/2011; · 3.69 Impact Factor -
Article: Molecular characterization and revised systematics of Microdiaphanosoma arcuatum (Ciliophora, Colpodea).
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ABSTRACT: Microdiaphanosoma arcuatum Wenzel, 1953 is a world-wide distributed ciliate, recorded mainly in soil samples, which we have also identified in ground water samples from South Africa. This ciliate has been frequently overlooked or not determined due to its small size, ∼12 μm. The genus Microdiaphanosoma is nowadays included in the class Colpodea, order Bryometopida, family Kreyellidae. The first complete small subunit (SSU) rDNA gene sequence of this ciliate was obtained from a South African isolate. Phylogenetic analysis including available SSU rDNA sequences from another Colpodea species in the GenBank strongly supported the position of M. arcuatum within the order Cyrtolophosidida instead of the order Bryometopida. The analysis also suggested a sister relationship between this species and species from the family Cyrtolophosididae.Journal of Eukaryotic Microbiology 01/2011; 58(2):114-9. · 2.66 Impact Factor -
Article: An evaluation of the use of the LSU rRNA D1-D5 domain for DNA-based taxonomy of eukaryotic protists.
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ABSTRACT: Diagnostic signature DNA sequences are important tools for the identification of species. There is an active debate in the literature on the choice of the best markers applicable for a broad range of organisms. Protists have seldom been included in these evaluations. Mitochondrial gene sequences are inappropriate for protists since several groups do not possess mitochondria. Here we studied the application of the large subunit (LSU) rRNA gene fragments (D1-D5) regarding their usefulness to discriminate between a wide range of heterotrophic nanoflagellates. Phylogenetic analyses based on the LSU rRNA fragments showed similar results compared to phylogenetic trees based on the small subunit (SSU) rRNA. The data set indicates the power of the use of the D1-D5 region as a marker for a DNA-based taxonomy. Our results, together with the available sequences in Genbank, form a comprehensive database for unicellular eukaryotes, especially heterotrophic flagellates. It is now possible to assign new sequences to the different groups of heterotrophic flagellates which we have tested for different closely related Cercomonas and Paracercomonas strains from groundwater.Protist 02/2010; 161(3):342-52. · 3.14 Impact Factor -
Article: Large-scale patterns in biodiversity of microbial eukaryotes from the abyssal sea floor.
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ABSTRACT: Eukaryotic microbial life at abyssal depths remains "uncharted territory" in eukaryotic microbiology. No phylogenetic surveys have focused on the largest benthic environment on this planet, the abyssal plains. Moreover, knowledge of the spatial patterns of deep-sea community structure is scanty, and what little is known originates primarily from morphology-based studies of foraminiferans. Here we report on the great phylogenetic diversity of microbial eukaryotic communities of all 3 abyssal plains of the southeastern Atlantic Ocean--the Angola, Cape, and Guinea Abyssal Plains--from depths of 5,000 m. A high percentage of retrieved clones had no close representatives in genetic databases. Many clones were affiliated with parasitic species. Furthermore, differences between the communities of the Cape Abyssal Plain and the other 2 abyssal plains point to environmental gradients apparently shaping community structure at the landscape level. On a regional scale, local species diversity showed much less variation. Our study provides insight into the community composition of microbial eukaryotes on larger scales from the wide abyssal sea floor realm and marks a direction for more detailed future studies aimed at improving our understanding of deep-sea microbes at the community and ecosystem levels, as well as the ecological principles at play.Proceedings of the National Academy of Sciences 12/2009; 107(1):115-20. · 9.68 Impact Factor -
Article: Effects of resource supplements on mature ciliate biofilms: an empirical test using a new type of flow cell.
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ABSTRACT: Biofilm-dwelling consumer communities play an important role in the matter flux of many aquatic ecosystems. Due to their poor accessibility, little is as yet known about the regulation of natural biofilms. Here, a new type of flow cell is presented which facilitates both experimental manipulation and live observation of natural, pre-grown biofilms. These flow cells were used to study the dynamics of mature ciliate biofilms in response to supplementation of planktonic bacteria. The results suggest that enhanced ciliate productivity could be quickly transferred to micrometazoans (ciliate grazers), making the effects on the standing stock of the ciliates detectable only for a short time. Likewise, no effect on ciliates appeared when micrometazoan consumers were ab initio abundant. This indicates the importance of 'top-down' control of natural ciliate biofilms. The flow cells used here offer great potential for experimentally testing such control mechanisms within naturally cultivated biofilms.Biofouling 11/2009; 25(8):769-78. · 4.43 Impact Factor -
Article: Composition of groundwater nanoprotist communities in different aquifers based on aliquot cultivation and genotype assessment of cercomonads
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ABSTRACT: Investigations into the protistan fauna of groundwater habitats are still underrepresented. We investigated 14 aquifers comprising studies in lowlands around Cologne, the Eifel Mountains and the Alps (depths ranging from 6 to 400 metres) with different abiotic conditions. 21 heterotrophic flagellate taxa, five ciliate, four amoeba taxa and one centrohelid heliozoan were recorded. There was no clear relationship between protozoan communities and abiotic parameters at the different sampling sites with the exception of bicosoecids and euglenids that were more abundant at higher nitrate/chloride concentrations. The abundance of cultivable protists in free aquifer water ranged between 0.1 and 3 ind/ml. At one sampling site, abundances in free and sediment-associated water were compared revealing a ten-times higher abundance in the latter. The diversity of genotypes was investigated for cercomonads. Studies of Cercomonas and Paracercomonas D3-D5 LSU rRNA sequences indicated that groundwater may be a habitat with a relatively large diversity of species. A high number of species is probably not yet discovered.Fundamental and Applied Limnology / Archiv für Hydrobiologie 03/2009; 174(3):261-269. · 1.14 Impact Factor -
Article: Responses of biofilm-dwelling ciliate communities to planktonic and benthic resource enrichment.
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ABSTRACT: Four experiments covering different seasons were performed to test the impact of increased benthic and planktonic resource availability on the structure of biofilm-dwelling ciliate communities which were cultivated in river bypass systems. The growth of benthic bacteria was stimulated by the addition of dissolved organic carbon. The enrichment of the planktonic resource was achieved by supplementation with suspended bacteria. It was shown that both resource enrichments can differentially influence abundance and taxonomic structure of ciliate communities. Furthermore, both resources can influence different stages during biofilm colonization. Increased benthic bacterial growth mainly resulted in both an accumulation of primarily grazing-resistant bacterial filaments and in an increase in the number of vagile heterotrophic flagellates. This can stimulate nanophagous ciliates (feeding on flagellates) in addition to the direct stimulation of bacteriovorous ciliates. The effects of the planktonic bacteria enrichments were twofold: They could have been utilized either directly by suspension-feeding ciliates or indirectly through an enhanced growth of suspension-feeding attached heterotrophic flagellates, which were then in turn grazed upon by ciliates. The magnitude of responses of the total ciliate abundance to the two resource enrichments further depended on the background conditions, thereby showing temporarily variable limitations of these resources. Furthermore, the particular taxonomic groups stimulated by one resource type sometimes differed between the experiments, an observation which demonstrates that the response depends on different environmental factors and is not easily predictable based simply on resource type. Taken together, our results emphasize the need of a differentiated view on the effects of resources on complex biofilm-dwelling consumer communities with respect to both the origin of carbon source as well as the particular environmental conditions.Microbial Ecology 01/2009; 57(4):687-700. · 2.91 Impact Factor -
Article: A new choanoflagellate species from Taiwan: morphological and molecular biological studies of Diplotheca elongata nov. spec. and D. costata.
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ABSTRACT: A new species of acanthoecid choanoflagellate isolated from brackish waters of the Danshui estuary in North Taiwan has a mineralized lorica that consists of two chambers with a total length of 19-36microm. It shares with Diplotheca costata the features of a posterior lorica chamber formed from broad and flattened costal strips and an anterior chamber with spatula-shaped costal strips. The new species has therefore been placed in the same genus and named Diplotheca elongata. A phylogenetic analysis of partial SSU rDNA sequences from Diplotheca costata and D. elongata supports this taxonomic affiliation. This is a large and distinctive choanoflagellate which has not been reported in any previous study, suggesting that it may be an endemic species of restricted distribution.European Journal of Protistology 09/2008; 44(3):220-6. · 1.97 Impact Factor -
Article: Impact of local temperature increase on the early development of biofilm-associated ciliate communities.
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ABSTRACT: Indications of global climate change and associated unusual temperature fluctuations have become increasingly obvious over the past few decades. Consequently, the relevance of temperature increases for ecological communities and for whole ecosystems is one of the major challenges of current ecological research. One approach to investigating the effects of increasing temperatures on communities is the use of fast-growing microbial communities. Here we introduce a river bypass system in which we tested the effect of temperature increases (0, 2, 4, 6 degrees C above the long-term average) on both the colonization speed and the carrying capacity of biofilm-associated ciliate communities under different seasonal scenarios. We further investigated interactions of temperature and resource availability by cross-manipulations in order to test the hypothesis that temperature-mediated effects will be strongest in environments that are not resource-limited. Strong seasonal differences in both tested parameters occurred under natural conditions (no resource addition), and the effects of temperature increase at a given time were relatively low. However, increasing temperature can significantly accelerate the colonization speed and reduce the carrying capacity in particular seasons. These effects were strongest in winter. Simultaneous manipulation of temperature and of resource availability amplified the response to temperature increase, adumbrating strong interactive control of populations by temperature and resource availability. Our results show that the response of communities to local temperature increases strongly depends on the seasonal setting, the resource availability and the stage of succession (early colonization speed vs. carrying capacity).Oecologia 04/2007; 151(2):341-50. · 3.41 Impact Factor -
Article: Control of microbial communities by the macrofauna: a sensitive interaction in the context of extreme summer temperatures?
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ABSTRACT: Climate models predict an increasing frequency of extremely hot summer events in the northern hemisphere for the near future. We hypothesised that microbial grazing by the metazoan macrofauna is an interaction that becomes unbalanced at high temperatures due to the different development of the grazing rates of the metazoans and the growth rates of the microbial community with increasing temperature. In order to test this hypothesis, we performed grazing experiments in which we measured the impact of increasing temperatures on the development of the grazing rates of riverine mussels in relation to the growth rates of a unicellular prey community (a natural heterotrophic flagellate community from a large river). In a first experimental series using Corbicula fluminea as a grazer and under the addition of a carbon source (yeast extract), the increase of the prey's growth rates was considerably stronger than that of the predator's grazing rates when temperatures were increased from 19 to over 25 degrees C. This was also the outcome when the mussels had been acclimatized to warm temperatures. Hereafter, specific experiments with natural river water at temperatures of 25 and 30 degrees C were performed. Again, a strong decrease of the mussels' grazing rates in relation to the flagellate growth rates with increasing temperature occurred for two mussel species (C. fluminea and Dreissena polymorpha). When performing the same experiment using a benthic microbial predator community (biofilms dominated by ciliates) instead of the benthic mussels, an increase of the grazing rates relative to the growth rates with temperature could be observed. Our data suggest that predator-prey interactions (between metazoans and microbes) that are balanced at moderate temperatures could become unbalanced at high temperatures. This could have significant effects on the structure and function of microbial communities in light of the predicted increasing frequency of summer heat waves.Oecologia 03/2007; 151(1):115-24. · 3.41 Impact Factor -
Article: Deep Sea Records of Choanoflagellates with a Description of Two New Species
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ABSTRACT: Despite their high abundance and their high importance for the oceanic matter flux, heterotrophic nanoflagellates are only poorly studied in the deep-sea regions. Studies on the choanoflagellate distribution during two deep-sea expeditions, to the South Atlantic (5038 m) and Antarctica (Weddell Sea, 2551 m), revealed the deepest records of choanoflagellates so far. A new species, (Lagenoeca antarctica) with a conspicuous spike structure on the theca is described from deep Antarctic waters. Lagenoeca antarctica sp. n. is a solitary unstalked free living salpingoecid-like choanoflagellate. The protoplast is surrounded by a typical theca with unique spikes only visible in SEM micrographs. The ovoid cell nearly fills the whole theca and ranges in size from 4 to 6 pm. The collar measures 2-3 μm and the flagellum 3-5 μm. A second species, Salpingoeca abyssalis sp. n., was isolated from the abyssal plain of the South Atlantic (5038 m depth). Floating and attached forms were observed. The protoplast ranges from to 2 to 4 μm in length and 1 to 2 μm in width. The collar is about the same length as the protoplast and the flagellum has 2 to 2.5 x the length of the protoplast. Phylogenetic analyses based on a fragment of SSU rDNA revealed Salpingoeca abyssalis to cluster together with a marine isolate of Salpingoeca infusionum while Lagenoeca antarctica clusters separately from the other codonosigid and salpingoecid taxa. Salpingoeca abyssalis and an undetermined Monosiga species seems to be the first choanoflagellate species recorded from the abyssal plain.Acta Protozoologica. 01/2007; 46:99-106. -
Article: Molecular comparisons of freshwater and marine isolates of the same morphospecies of heterotrophic flagellates.
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ABSTRACT: Heterotrophic flagellates are key components of all ecosystems. Understanding the patterns of biodiversity of these organisms is thus particularly important. Here we analyzed the intraspecific diversity of 10 morphospecies of heterotrophic flagellates comprising representatives of the Apusozoa (2 morphospecies) and Kinetoplastea (8 morphospecies), all belonging to the most common flagellates with worldwide distribution. Most morphospecies showed a mixing of lineages isolated from diverse habitats, indicating that some lineages of these morphospecies had been able to colonize different habitats several times. Furthermore, our results revealed remarkable levels of genetic divergence within most of the morphospecies studied, underlining the difficulty of correctly determining species by means of morphology alone. Many cryptic or pseudocryptic species seem to occur. Our results revealed clear divergence between marine and freshwater lineages of the morphospecies Ancyromonas sigmoides, showing that freshwater lineages have not been able to colonize marine environments and marine lineages have not been able to colonize freshwater environments for a long time.Applied and Environmental Microbiology 11/2006; 72(10):6638-43. · 3.83 Impact Factor -
Article: Cryptic species in a morphospecies complex of heterotrophic flagellates : the case study of Caecitellus spp
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ABSTRACT: Recent molecular studies have revealed quite different genotypes within morphospecies of heterotrophic nanoflagellates (HNF) as identified by light microscopy, e.g. for Caecitellus parvulus, known as one of the 20 most common heterotrophic flagellates worldwide. We combined molecular and morphological analyses to clarify if the morphospecies Caecitellus parvulus includes genetically as well as ultrastructurally and behaviourally distinguishable species with or without a different geographical distribution. Therefore we compared the ultrastructure, the small subunit of the ribosomal DNA (SSU rDNA), the growth rates as well as the locomotion patterns of two strains of C. cf. parvulus isolated from deep sea sediments and from the surface water of the oligotrophic Angola Basin, South Atlantic. The reconstruction of the kinetid architecture of two strains of C. cf. parvulus revealed differences in the number of microtubules in flagellar root 3, which surrounds the oral region and forms the cytoskeleton of the feeding basket. The number of microtubules in this region is also different from the description given earlier in the literature for Caecitellus parvulus. Additionally, there are significant differences between the two studied strains in the length of their posterior flagellum, their locomotion velocity and their moving pattern as well as in their growth rates. These observations, together with the results of the molecular comparison of the SSU rDNA of 11 different strains of Caecitellus, suggest the existence of at least three distinguishable species. Our results indicate cryptic speciation within the morphospecies Caecitellus parvulus. We describe two new Caecitellus species, i.e. Caecitellus paraparvulus and Caecitellus pseudoparvulus, which have been newly established within a Caecitellus-complex.Acta Protozoologica. 01/2006; 45:415-431. -
Article: Experimental demonstration of chaos in a microbial food web.
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ABSTRACT: Discovering why natural population densities change over time and vary with location is a central goal of ecological and evolutional disciplines. The recognition that even simple ecological systems can undergo chaotic behaviour has made chaos a topic of considerable interest among theoretical ecologists. However, there is still a lack of experimental evidence that chaotic behaviour occurs in the real world of coexisting populations in multi-species systems. Here we study the dynamics of a defined predator-prey system consisting of a bacterivorous ciliate and two bacterial prey species. The bacterial species preferred by the ciliate was the superior competitor. Experimental conditions were kept constant with continuous cultivation in a one-stage chemostat. We show that the dynamic behaviour of such a two-prey, one-predator system includes chaotic behaviour, as well as stable limit cycles and coexistence at equilibrium. Changes in the population dynamics were triggered by changes in the dilution rates of the chemostat. The observed dynamics were verified by estimating the corresponding Lyapunov exponents. Such a defined microbial food web offers a new possibility for the experimental study of deterministic chaos in real biological systems.Nature 07/2005; 435(7046):1226-9. · 36.28 Impact Factor -
Article: Molecular identity of strains of heterotrophic flagellates from surface waters and deep-sea sediments of the South Atlantic based on SSU rDNA
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ABSTRACT: Whereas much is known about the biodiversity of prokaryotes and macroorganisms in the deep sea, knowledge on the biodiversity of protists remains very limited. Molecular studies have changed our view of marine environments and have revealed an astonishing number of previously unknown eukaryotic organisms. Morphological findings have shown that at least some widely distributed nanoflagellates can also be found in the deep sea. Whether these flagellates have contact with populations from other habitats is still uncertain. We performed a molecular comparison of strains isolated from deep-sea sediments (>5000 m depth) and surface waters on the basis of their small subunit ribosomal DNA (SSU rDNA). Sequences of Rhynchomonas nasuta, Amastigomonas debruynei, Ancyromonas sigmoides, Cafeteria roenbergensis and Caecitellus parvulus were analysed, and 2 contrasting results obtained. Firstly, we found nearly identical genotypes within 1 morphospecies (C. roenbergensis), and secondly, quite different genotypes within certain morphospecies (R. nasuta, A. sigmoides and C. parvulus). In addition, high genetic distances between the different strains of A. sigmoides and C. parvulus indicate that these morphospecies should be divided into different at least genetically distinguishable species. In contrast, some heterotrophic nanoflagellates must indeed be regarded as being cosmopolitan. According to the low genetic distances between isolates of R. nasuta, A. debruynei and C. roenbergensis as well as between our isolates of A. sigmoides from deep-sea and surface waters, exchanges between these habitats and also on a global scale might be possible. In summary, our results show that 3 morphospecies obviously contain several cryptic species, while some of the investigated genotypes occur in both deep-sea as well as in surface waters.Aquatic Microbial Ecology. 01/2005; 38:239-247.
Top co-authors
Top Journals
Institutions
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2011
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Helmholtz-Zentrum für Umweltforschung
- Department Fließgewässerökologie
Leipzig, Saxony, Germany
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2000–2011
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Universität Köln
- Zoological Institute
Köln, North Rhine-Westphalia, Germany
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2002
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Austrian Academy of Sciences
- Institut für Limnologie
Vienna, Vienna, Austria
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