The heterotrophic bacterium Cupriavidus pinatubonensis JMP134 oxidizes sulfide to sulfate with thiosulfate as a key intermediate.

The heterotrophic bacterium Cupriavidus pinatubonensis JMP134 oxidizes sulfide to sulfate with thiosulfate as a key intermediate. Appl Environ Microbiol. 2020 Sep 11;: Authors: Xin Y, Gao R, Cui F, Lü C, Liu H, Liu H, Xia Y, Xun L Abstract Heterotrophic bacteria actively participate in the biogeochemical cycle of sulfur on Earth. The heterotrophic bacterium Cupriavidus pinatubonensis JMP134 contains several enzymes involved in sulfur oxidation, but how these enzymes work together to oxidize sulfide in the bacterium has not been studied. Using gene-deletion and whole cell assays, we determined that the bacterium uses sulfide:quinone oxidoreductase to oxidize sulfide to polysulfide, which is further oxidized to sulfite by persulfide dioxygenase. Sulfite spontaneously reacts with polysulfide to produce thiosulfate. The Sox system oxidizes thiosulfate to sulfate. Flavocytochrome c sulfide dehydrogenase enhances thiosulfate oxidation by the Sox system, but couples with the Sox system for sulfide oxidation to sulfate in the absence of sulfide:quinone oxidoreductase. Thus, C. pinatubonensis JMP134 contains a main pathway and a contingent pathway for sulfide oxidation.Importance We establish a new pathway of sulfide oxidation with thiosulfate as a key intermediate in Cupriavidus pinatubonensis JMP134. The bacterium mainly oxidizes sulfide by using sulfide:quinone oxidoreductase, persulfide dioxygenase, and the Sox system with thiosulfate as...
Source: Applied and Environmental Microbiology - Category: Microbiology Authors: Tags: Appl Environ Microbiol Source Type: research