Biophysical Controls on Community Succession in Stream Biofilms
| Autor: | Katharina Besemer, Ann-Kathrin Chlup, Iris Hödl, Tom J. Battin, Romana Limberger, Christian Baranyi, Gerald Hochedlinger, Gabriel Singer |
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| Rok vydání: | 2007 |
| Předmět: |
DNA
Bacterial Molecular Sequence Data Ecological succession Biology Applied Microbiology and Biotechnology Ecosystem engineer Microbial Ecology Rivers Species Specificity RNA Ribosomal 16S Proteobacteria Water Movements Ecosystem Phylogeny Bacteria Ecology Biofilm Eukaryota Laminar flow Sequence Analysis DNA biochemical phenomena metabolism and nutrition Flow conditions Biofilms Electrophoresis Polyacrylamide Gel Microcosm Temperature gradient gel electrophoresis Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 73:4966-4974 |
| ISSN: | 1098-5336 0099-2240 |
| DOI: | 10.1128/aem.00588-07 |
| Popis: | Biofilm formation is controlled by an array of coupled physical, chemical, and biotic processes. Despite the ecological relevance of microbial biofilms, their community formation and succession remain poorly understood. We investigated the effect of flow velocity, as the major physical force in stream ecosystems, on biofilm community succession (as continuous shifts in community composition) in microcosms under laminar, intermediate, and turbulent flow. Flow clearly shaped the development of biofilm architecture and community composition, as revealed by microscopic investigation, denaturing gradient gel electrophoresis (DGGE) analysis, and sequencing. While biofilm growth patterns were undirected under laminar flow, they were clearly directed into ridges and conspicuous streamers under turbulent flow. A total of 51 biofilm DGGE bands were detected; the average number ranged from 13 to 16. Successional trajectories diverged from an initial community that was common in all flow treatments and increasingly converged as biofilms matured. We suggest that this developmental pattern was primarily driven by algae, which, as “ecosystem engineers,” modulate their microenvironment to create similar architectures and flow conditions in all treatments and thereby reduce the physical effect of flow on biofilms. Our results thus suggest a shift from a predominantly physical control to coupled biophysical controls on bacterial community succession in stream biofilms. |
| Databáze: | OpenAIRE |
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