Molecular mechanism of sulfur chemolithotrophy in the betaproteobacterium Pusillimonas ginsengisoli SBSA.

Molecular mechanism of sulfur chemolithotrophy in the betaproteobacterium Pusillimonas ginsengisoli SBSA. Microbiology. 2020 Jan 30;: Authors: Mandal S, Rameez MJ, Chatterjee S, Sarkar J, Pyne P, Bhattacharya S, Shaw R, Ghosh W Abstract Chemolithotrophic sulfur oxidation represents a significant part of the biogeochemical cycling of this element. Due to its long evolutionary history, this ancient metabolism is well known for its extensive mechanistic and phylogenetic diversification across a diverse taxonomic spectrum. Here we carried out whole-genome sequencing and analysis of a new betaproteobacterial isolate, Pusillimonas ginsengisoli SBSA, which is found to oxidize thiosulfate via the formation of tetrathionate as an intermediate. The 4.7 Mb SBSA genome was found to encompass a soxCDYZAXOB operon, plus single thiosulfate dehydrogenase (tsdA) and sulfite : acceptor oxidoreductase (sorAB) genes. Recombination-based knockout of tsdA revealed that the entire thiosulfate is first converted to tetrathionate by the activity of thiosulfate dehydrogenase (TsdA) and the Sox pathway is not functional in this bacterium despite the presence of all necessary sox genes. The ∆soxYZ and ∆soxXA knockout mutants exhibited a wild-type-like phenotype for thiosulfate/tetrathionate oxidation, whereas ∆soxB, ∆soxCD and soxO::KanR mutants only oxidized thiosulfate up to tetrathionate intermediate and had complete impairment in tetrathionate...
Source: Microbiology - Category: Microbiology Authors: Tags: Microbiology Source Type: research