Responses of Biofilm-Dwelling Ciliate Communities to Planktonic and Benthic Resource Enrichment

Norf, Helge; Arndt, Hartmut; Weitere, Markus

doi:10.1007/s00248-008-9470-z

Cited by 73 publications

(57 citation statements)

References 41 publications

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“…The three less impacted sites in this study also receive significant amounts of allochthonous debris from surrounding vegetation, while site 4 does not, suggesting a difference in the relative importance of detritus-derived nutrients in these streams. Elevated nutrient availability can increase benthic ciliate abundance in rivers and streams (19,50,58) and may affect ciliate abundance, biomass, and community composition in lentic habitats (2,33,51,76). It seems possible that the abundant biofilms in the more impacted streams in this study may provide more resources and a wider variety of feeding niches for heterotrophic protozoan organisms.…”

Section: Vol 75 2009 Diversity Of Ciliates In Stream Biofilms 5267mentioning

confidence: 90%

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Dopheide

Lear

Stott

et al. 2009

Appl Environ Microbiol

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Ciliates are an important component of aquatic ecosystems, acting as predators of bacteria and protozoa and providing nutrition for organisms at higher trophic levels. Understanding of the diversity and ecological role of ciliates in stream biofilms is limited, however. Ciliate diversity in biofilm samples from four streams subject to different impacts by human activity was assessed using microscopy and terminal restriction fragment length polymorphism (T-RFLP) analysis of 18S rRNA sequences. Analysis of 3 and 5 terminal fragments yielded very similar estimates of ciliate diversity. The diversity detected using microscopy was consistently lower than that suggested by T-RFLP analysis, indicating the existence of genetic diversity not apparent by morphological examination. Microscopy and T-RFLP analyses revealed similar relative trends in diversity between different streams, with the lowest level of biofilm-associated ciliate diversity found in samples from the least-impacted stream and the highest diversity in samples from moderately to highly impacted streams. Multivariate analysis provided evidence of significantly different ciliate communities in biofilm samples from different streams and seasons, particularly between a highly degraded urban stream and less impacted streams. Microscopy and T-RFLP data both suggested the existence of widely distributed, resilient biofilm-associated ciliates as well as ciliate taxa restricted to sites with particular environmental conditions, with cosmopolitan taxa being more abundant than those with restricted distributions. Differences between ciliate assemblages were associated with water quality characteristics typical of urban stream degradation and may be related to factors such as nutrient availability and macroinvertebrate communities. Microscopic and molecular techniques were considered to be useful complementary approaches for investigation of biofilm ciliate communities.Heterotrophic microeukaryotes such as ciliates are thought to be of considerable importance in aquatic ecosystems, as they are major predators of bacteria and constitute a nutritional resource for other protozoa, invertebrates, and probably fish larvae (9,22,36,52,62,63,71). In addition, protozoan bacterivory contributes to enhanced decomposition of leaf detritus-a vital nutrient resource in streams-by increasing turnover of bacterial populations through predation (57). It is not well understood, however, how ciliate diversity and community structure in streams are affected by changing environmental conditions, or how ciliate communities affect other stream biota and processes. The effects of various physical, chemical, and biological factors on freshwater protozoan communities have been considered by a number of studies, but most of these have focused upon planktonic organisms in lentic habitats (for example, see references 2, 11, and 44). However, the complex microbial communities in biofilms have been recognized as important contributors to critical ecological processes, such as auxotrophic primary ...

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Section: Vol 75 2009 Diversity Of Ciliates In Stream Biofilms 5267mentioning

confidence: 90%

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Dopheide

Lear

Stott

et al. 2009

Appl Environ Microbiol

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“…Biofilm colonization of rubber stoppers was allowed for 56 days (20th September-15th November 2012), a period deemed long enough for the establishment of mature biofilm communities in temperate rivers (e.g. Norf et al, 2009). The ambient N-NO 3 -concentration at the study site-measured on water river samples collected for non-nutrient-enriched microcosms (see below)-ranged between 0.48 and 0.55 mg l -1 during the biofilm incubation.…”

Section: In Situ Biofilm Growthmentioning

confidence: 99%

Short-term effects of nutrient enrichment on river biofilm: N–NO3 − uptake rate and response of meiofauna

et al. 2014

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Biofilms play a key role in self-depuration processes in rivers. Whilst meiofauna is known to be abundant within river phototrophic biofilms and to perform both grazing and bioturbation within these matrixes, it is still unknown whether the activity of biofilm-associated meiofauna can influence the ability of biofilms to improve river water quality. In this study, we explored the effects of nutrient enrichment on river biofilm N-NO 3 -uptake rates and associated meiofauna in microcosms for 5 days under nutrientenriched/non-enriched conditions. Short-time nutrient enrichment stimulated biofilm-associated bacterial and rotifer density, as well as the biofilm uptake rates of N-NO 3 -, but not algal biomass. Under nonenriched conditions, N-NO 3 -uptake rate tended to reach a plateau around 104.2 lg g -1 AFDM h -1 . At higher N-NO 3 -concentrations, realised under enrichment, N-NO 3 -uptake rate seemed to increase linearly, reaching up to 439.2 lg g -1 AFDM h -1 . Our results showed a rapid response of rotifers to nitrate enrichment and suggest a possible link between bacteria-meiofauna interactions and the short-term N uptake capacity of biofilms.

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“…Protozoans in biofilms can have strong impacts on bacterial abundances and spatial heterogeneity, bacterial and microalgal species assemblages, biofilm architecture, and sloughing dynamics (Jackson & Jones 1991, McCormick 1991, Arndt et al 2003, Parry 2004, Parry et al 2007). The diverse protozoans in biofilms have complex trophic interactions, seasonal variations, successional dynamics, and constraints from the flow regime and other environmental factors (Franco et al 1998, Sekar et al 2002, Arndt et al 2003, Gong et al 2005, Wey et al 2008, Norf et al 2009, Risse-Buhl & Küsel 2009. Although the literature on biofilm protozoa is considerable in size, it deals almost entirely with freshwater systems, and relatively little is known about the dynamics of protozoans in marine biofilms.…”

Section: Introductionmentioning

confidence: 99%

Influences of biofilm-associated ciliates on the settlement of marine invertebrate larvae

Shimeta¹,

Cutajar²,

Watson³

et al. 2012

Mar. Ecol. Prog. Ser.

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Settlement of benthic marine invertebrate larvae often limits recruitment, influencing the structure and dynamics of natural populations as well as biofouling of marine infrastructure, ship hulls, and aquaculture operations. Certain microbial components of substratum biofilms influence settlement (e.g. bacteria, diatoms), but the importance of biofilm protozoa has been unknown. We tested for effects of ciliates by comparing settlement and survival of common fouling invertebrates among 3 biofilm conditions: no biofilm, a purely bac terial biofilm, and a biofilm of bacteria and ciliates. With an assemblage of 7 ciliates (from Hypotrichia, Haptoria, and Scuticociliatia), the serpulid polychaete Galeolaria caespitosa showed a 44 to 49% average reduction in settlement rate compared to the purely bacterial biofilm, and post-settlement mortality increased 7-fold to 34%. In contrast, settlement and survival of the bryozoan Bugula neritina were unaffected. With a partially different assemblage of 11 ciliates (from Hypotrichia, Sticho trichia, Haptoria, Colpodida, and Scuticociliatia), settle ment of the serpulid Pomatoceros taeniata more than doubled, whereas that of the blue mussel Mytilus galloprovincialis was reduced by 54% compared to the purely bacterial biofilm. The results could not be explained by ciliates changing the total abundance of biofilm bacteria. We hypothesize that mechanisms could include direct interactions between larvae and ciliates (physical interactions, interference from ciliates' feeding currents, or responses to chemicals from ciliates), or indirect effects from ciliates altering the bacterial assemblage or its settlement cues. Such large and species-specific effects of ciliates on larval settlement and postsettlement mortality might impact invertebrate recruitment rates and species assemblages, especially because biofilm ciliates are highly variable over time and space.Aggregation of the tubeworm Galeolaria caespitosa. Larval settlement of these and other invertebrates is influenced by ciliates on the substratum.

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Responses of Biofilm-Dwelling Ciliate Communities to Planktonic and Benthic Resource Enrichment

Cited by 73 publications

References 41 publications

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Relative Diversity and Community Structure of Ciliates in Stream Biofilms According to Molecular and Microscopy Methods

Short-term effects of nutrient enrichment on river biofilm: N–NO3 − uptake rate and response of meiofauna

Influences of biofilm-associated ciliates on the settlement of marine invertebrate larvae

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