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.

• Klíčová slova
• Element cycles, Genome annotation, Haloalkaliphiles, Rhodobacterales, Soda lake,
• MeSH
• anotace sekvence MeSH
• fyziologická adaptace MeSH
• genom bakteriální * MeSH
• jezera mikrobiologie   MeSH
• Rhodobacteraceae genetika   fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH

A psychrophilic fungal strain of Geomyces pannorum P15 was screened for its ability to utilize a range of synthetic and natural organophosphonate compounds as the sole source of phosphorus, nitrogen, or carbon. Only phosphonoacetic acid served as a phosphorus source for microbial growth in phosphate-independent manner. Substrate metabolism did not lead to extracellular release of inorganic phosphate. No phosphonate metabolizing enzyme activity was detectable in cell-free extracts prepared from Geomyces biomass pregrown on 2 mmol/L phosphonoacetic acid.

• MeSH
• Ascomycota růst a vývoj   metabolismus   MeSH
• dusík metabolismus   MeSH
• fosfáty metabolismus   MeSH
• fosfor metabolismus   MeSH
• kyselina fosfonoctová metabolismus   MeSH
• uhlík metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• dusík MeSH
• fosfáty MeSH
• fosfor MeSH
• kyselina fosfonoctová MeSH
• uhlík MeSH