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A 2-Year Assessment of the Main Environmental Factors Driving the Free-Living Bacterial Community Structure in Lake Bourget (France)
| Content Provider | Semantic Scholar |
|---|---|
| Author | Berdjeb, Lyria Ghiglione, Jean François Domaizon, Isabelle Jacquet, Stéphan |
| Copyright Year | 2010 |
| Abstract | Despite the considerable attention that has been paid to bacterioplankton over recent decades, the dynamic of aquatic bacterial community structure is still poorly understood, and long-term studies are particularly lacking. Moreover, how the environment governs diversity patterns remains a key issue in aquatic microbial ecology. In this study, we used denaturing gradient gel electrophoresis of PCR-amplified partial 16S rRNA gene fragments and multivariable statistical approaches to explore the patterns of change in the free-living bacterial community in the mesotrophic and mono-meromictic Lake Bourget (France). A monthly sampling was conducted over two consecutive years (2007 and 2008) and at two different depths characterizing the epi- and hypolimnion of the lake (2 and 50 m, respectively). Temporal shifts in the bacterial community structure followed different patterns according to depth, and no seasonal reproducibility was recorded from 1 year to the next. Our results showed that the bacterial community structure displayed lower diversity at 2 m (22 bands) compared to 50 m (32 bands) and that bacterial community structure dynamics followed dissimilar trends between the two depths. At 2 m, five shifts in the bacterial community structure occurred, with the temporal scale varying between 2 and 8 months whereas, at 50 m, four shifts in the bacterial community structure took place at 50 m, with the temporal scale fluctuating between 3 and 13 months. More than 60% of the bacterial community structure variance was explained by seven variables at 2 m against eight at 50 m. Nutrients (PO4-P, NH4-N and NO3-N) and temperature were responsible for 49.6% of the variance at 2 m whereas these nutrients, with dissolved oxygen and chlorophyll a accounting for 59.6% of the variance at 50 m. Grazing by ciliates played also a critical role on the bacterial community structure at both depths. Our results suggest that the free-living bacterial community structure in the epi- and hypolimnion of Lake Bourget is mainly driven by combined, but differently weighted, top-down and bottom-up factors at 2 and 50 m. |
| Starting Page | 941 |
| Ending Page | 954 |
| Page Count | 14 |
| File Format | PDF HTM / HTML |
| DOI | 10.1007/s00248-010-9767-6 |
| PubMed reference number | 21082178 |
| Journal | Medline |
| Volume Number | 61 |
| Alternate Webpage(s) | http://jacquet.stephan.free.fr/Berdjeb_ME_2011.pdf |
| Alternate Webpage(s) | https://doi.org/10.1007/s00248-010-9767-6 |
| Journal | Microbial Ecology |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
