Аннотация:Chemotrophic sulfur-oxidizing bacteria (SOB) represent an important functional group of microorganisms responsible for the dark oxidation of reduced sulfur compounds generated by sulfidogens. Until recently, only a single genus of halophilic SOB (Halothiobacillus) has been described, and nothing was known about the ability of this group to grow at high pH.
Investigation of soda lakes, unique extremely alkaline and saline habitats, led to the discovery of a novel ecotype of natronophilic SOB. In contrast to the previously known neutrophilic ecotype, this group cannot grow at neutral pH, but grows optimally in soda brines at pH values around 10. They were the first chemolithoautotrophs among the described alkaliphiles.
Overall, the investigation of hypersaline and (halo)alkaline habitats uncovered a novel and diverse world of extremophilic SOB with properties previously unknown for chemolithoautotrophic bacteria.