Effect of salinity on diazotrophic activity and microbial composition of phototrophic communities from Bitter-1 soda lake (Kulunda Steppe, Russia)
| Autor: | Gennadii V Borisenko, Tatiana P. Tourova, O. S. Samylina, Zorigto Namsaraev, M. V. Sukhacheva, Dimitry Y. Sorokin |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
0301 basic medicine
Cyanobacteria Salinity Soda lakes 030106 microbiology Microbiology 03 medical and health sciences Nitrogen fixation Purple sulfur bacteria Botany Nodularia Phototroph biology Sulfates Chemistry Microbiota Phototrophic bacteria Sulfate-reducing bacteria General Medicine biology.organism_classification Anoxygenic photosynthesis Siberia Lakes Fermentation Hypersaline Molecular Medicine Diazotroph |
| Zdroj: | Extremophiles: life under extreme conditions |
| ISSN: | 1431-0651 |
| Popis: | Bitter-1 is a shallow hypersaline soda lake in Kulunda Steppe (Altai region, Russia). During a study period between 2005 and 2016, the salinity in the littoral area of the lake fluctuated within the range from 85 to 400 g/L (in July of each year). Light-dependent nitrogen fixation occurred in this lake up to the salt-saturating conditions. The rates increased with a decrease in salinity, both under environmental conditions and in laboratory simulations. The salinities below 100 g/L were favorable for light-dependent nitrogen fixation, while the process was dramatically inhibited above 200 g/L salts. The analysis of nifH genes in environmental samples and in enrichment cultures of diazotrophic phototrophs suggested that anaerobic fermenting and sulfate-reducing bacteria could participate in the dark nitrogen fixation process up to soda-saturating conditions. However, we cannot exclude the possibility that haloalkaliphilic nonheterocystous cyanobacteria (Euhalothece sp. and Geitlerinema sp.) and anoxygenic purple sulfur bacteria (Ectothiorhodospira sp.) might also play a role in the process at light conditions. The heterocystous cyanobacterium Nodularia sp. develops at low salinity (below 80 g/L) that is not characteristic for Bitter-1 Lake and thus does not make a significant contribution to the nitrogen fixation in this lake. |
| Databáze: | OpenAIRE |
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