Physiological and Genomic Characterization of a Novel Obligately Chemolithoautotrophic, Sulfur-Oxidizing Bacterium of Genus Isolated from a Coastal Sediment.

species, belonging to the family in the phylum are usually detected in various sulfur-rich marine environments. However, only a few bacteria of have been isolated, and their ecological roles and environmental adaptations still require further understanding. Here, we report a novel strain, XGS-01, isolated from a coastal sediment, which belongs to genus and is most closely related to MAS2, with a sequence similarity of 97.8%. Phenotypic characterization showed that XGS-01 is a mesophilic, sulfur-oxidizing, obligate chemolithoautotrophy, with carbon dioxide as its sole carbon source and oxygen as its sole electron acceptor. During thiosulfate oxidation, strain XGS-01 can produce extracellular sulfur of elemental α-S, as confirmed via scanning electron microscopy and Raman spectromicroscopy. Polyphasic taxonomy results indicate that strain XGS-01 represents a novel species of the genus , named sp. nov. Genomic analysis confirmed that XGS-01 performed thiosulfate oxidation through a multienzyme complex, and harbored and genes for sulfide oxidation. Comparative genomics analysis among five available genomes from species revealed that carbon fixation via the oxidation of reduced-sulfur compounds coupled with oxygen reduction is conserved metabolic pathways among members of genus .