Metabolic Potential of Sulfobacillus thermotolerans: Pathways for Assimilation of Nitrogen Compounds and the Possibility of Lithotrophic Growth in the Presence of Molecular Hydrogen

Abstract

Sulfobacillus thermotolerans predominates in communities of acidophilic chemolithotrophic microorganisms and is of practical importance to biotechnologies for sulfide minerals processing. This is the first report on the presence of the genes encoding a quinone-binding [Fe-Ni] hydrogenase in S. thermotole-rans genome; this microorganism is therefore potentially capable of lithotrophic growth in the presence of molecular hydrogen. Components of the pathways for nitrogen compounds assimilation by S. thermotolerans probably include two assimilatory nitrate reductases, while NO dioxygenase and nitronate monooxygenases are probably involved in detoxication of nitric oxide and nitrocompounds. Research on the pathways of assimilation and detoxication of nitrogen compounds, as well as on alternative electron donors and acceptors in sulfobacilli will improve our understanding of the interactions within acidophilic chemolithotrophic communities in nature and industry.