Title |
Effect of salinity on diazotrophic activity and microbial composition of phototrophic communities from Bitter-1 soda lake (Kulunda Steppe, Russia)
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Published in |
Extremophiles, April 2018
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DOI | 10.1007/s00792-018-1026-7 |
Pubmed ID | |
Authors |
Zorigto Namsaraev, Olga Samylina, Marina Sukhacheva, Gennadii Borisenko, Dimitry Y. Sorokin, Tatiana Tourova |
Abstract |
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. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
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Unknown | 19 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
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Researcher | 4 | 21% |
Other | 2 | 11% |
Student > Bachelor | 2 | 11% |
Student > Master | 2 | 11% |
Student > Ph. D. Student | 1 | 5% |
Other | 2 | 11% |
Unknown | 6 | 32% |
Readers by discipline | Count | As % |
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Biochemistry, Genetics and Molecular Biology | 3 | 16% |
Immunology and Microbiology | 3 | 16% |
Environmental Science | 2 | 11% |
Engineering | 2 | 11% |
Other | 0 | 0% |
Unknown | 6 | 32% |