The complete genome sequence of Rhodobaca barguzinensis alga05 (DSM 19920) documents its adaptation for life in soda lakes

0495205 - MBÚ 2019 RIV JP eng J - Journal Article
Kopejtka, Karel - Tomasch, J. - Bunk, B. - Sproeer, C. - Wagner-Doebler, I. - Koblížek, Michal
The complete genome sequence of Rhodobaca barguzinensis alga05 (DSM 19920) documents its adaptation for life in soda lakes.
Extremophiles. Roč. 22, č. 6 (2018), s. 839-849. ISSN 1431-0651. E-ISSN 1433-4909
R&D Projects: GA ČR GBP501/12/G055; GA MŠMT(CZ) LO1416
Institutional support: RVO:61388971
Keywords : Element cycles * Genome annotation * Haloalkaliphiles
OECD category: Biochemistry and molecular biology
Impact factor: 2.046, year: 2018

Soda lakes, with their high salinity and high pH, pose a very challenging environment for life. Microorganisms living in these harsh conditions have had to adapt their physiology and gene inventory. Therefore, we analyzed the complete genome of the haloalkaliphilic photoheterotrophic bacterium Rhodobaca barguzinensis strain alga05. It consists of a 3,899,419 bp circular chromosome with 3624 predicted coding sequences. In contrast to most of Rhodobacterales, this strain lacks any extrachromosomal elements. To identify the genes responsible for adaptation to high pH, we compared the gene inventory in the alga05 genome with genomes of 17 reference strains belonging to order Rhodobacterales. We found that all haloalkaliphilic strains contain the mrpB gene coding for the B subunit of the MRP Na+/H+ antiporter, while this gene is absent in all non-alkaliphilic strains, which indicates its importance for adaptation to high pH. Further analysis showed that alga05 requires organic carbon sources for growth, but it also contains genes encoding the ethylmalonyl-CoA pathway for CO2 fixation. Remarkable is the genetic potential to utilize organophosphorus compounds as a source of phosphorus. In summary, its genetic inventory indicates a large flexibility of the alga05 metabolism, which is advantageous in rapidly changing environmental conditions in soda lakes.
Permanent Link: http://hdl.handle.net/11104/0288222