Effect of salinity on diazotrophic activity and microbial composition of phototrophic communities from Bitter-1 soda lake (Kulunda Steppe, Russia)

Namsaraev, Zorigto; Samylina, Olga; Sukhacheva, Marina; Borisenko, Gennadii; Sorokin, Dimitry Y.; Tourova, Tatiana

doi:10.1007/s00792-018-1026-7

Effect of salinity on diazotrophic activity and microbial composition of phototrophic communities from Bitter-1 soda lake (Kulunda Steppe, Russia)

Title

Effect of salinity on diazotrophic activity and microbial composition of phototrophic communities from Bitter-1 soda lake (Kulunda Steppe, Russia)

Author

Namsaraev, Zorigto (NRC “Kurchatov Institute”)
Samylina, Olga (Russian Academy of Sciences)
Sukhacheva, Marina (Russian Academy of Sciences)
Borisenko, Gennadii (Moscow State University)
Sorokin, Dimitry Y. (TU Delft BT/Environmental Biotechnology; Russian Academy of Sciences)
Tourova, Tatiana (Russian Academy of Sciences)

Date

2018-04-16

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.

Subject

Hypersaline
Nitrogen fixation
Phototrophic bacteria
Soda lakes
Sulfate-reducing bacteria

To reference this document use:

http://resolver.tudelft.nl/uuid:b3419eaf-792b-47d1-8a48-6c87ce920af8

DOI

https://doi.org/10.1007/s00792-018-1026-7

Embargo date

2019-02-26

ISSN

1431-0651

Source

Extremophiles: life under extreme conditions, 1-13