Isolation and characterization of Bacillus thioparus sp. nov., chemolithoautotrophic, thiosulfate-oxidizing bacterium

Abstract

A novel bacterium, strain BMP-1T, was isolated from a continuous wastewater treatment culture system operating with a bacterial consortium. Cells of the isolate were Gram-variable, aerobic, moderately halotolerant, motile and endospore-forming rods. Strain BMP-1T grew chemolithoautotrophically by oxidation of thiosulfate to sulfate with a growth yield of 1.07 g protein mol-1 of thiosulfate consumed. DNA G+C content was 43.8 mol%. Its cell wall had peptidoglycan based on m-diaminopimelic acid, and the major component of fatty acid was C15 : 0. The 16S rRNA gene analysis showed that strain belongs to the genus Bacillus, sharing a 99.5% of sequence similarity with Bacillus jeotgali CCM 7133T. DNA-DNA hybridization between the isolate of this study and this strain was 44%. Thus, the inclusion of strain BMP-1T in the genus Bacillus is suggested as a novel species and the name Bacillus thioparus sp. nov. (Type strain BMP-1T=BM-B-436T=CECT 7196T) is proposed. The sequence of the 16S rRNA gene has been deposited in GenBank with accession number DQ371431. © 2007 Federation of European Microbiological Societies.