Bacillus ferrooxidans sp. nov., an iron(II)-oxidizing bacterium isolated from paddy soil.

An endospore-forming bacterium, designated YT-3T, was isolated from a paddy soil in Yingtan, Jiangxi, China. Cells of strain YT-3T were Gram-positive, rod-shaped, facultative anaerobic, catalase, and oxidase positive. The optimum growth temperature and pH were 30°C (ranged from 15 to 50°C) and 6.5-7.0 (ranged from 3 to 11), respectively. Analysis of the 16S rRNA gene sequence showed that strain YT-3T was affiliated to the genus Bacillus and displayed the highest similarity to that of Bacillus drentensis JCM 21707T (98.3%), followed by B. ginsengisoli JCM 17335T (97.8%) and B. fumarioli JCM 21708T (97.0%). The similarity of rpoB gene sequence between strain YT-3T and B. drentensis JCM 21707T, B. ginsengisoli JCM 17335T and B. fumarioli JCM 21708T was 80.4%, 81.5%, and 82.1%, respectively. The genomic DNA G + C content was 44.9 mol%. The predominant respiratory quinone was Menaquinone-7, and meso-diaminopimelic acid was present in the peptidoglycan layer of cell wall. The major fatty acids were C15:0 anteiso (36.2%), C14:0 iso (19.6%), C15:0 iso (17.4%), and C16:0 iso (9.8%). The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phospholipids, and ammoniac phospholipids. The DNA-DNA hybridization values between isolate YT-3T and B. drentensis (JCM 21707T), B. ginsengisoli (JCM 17335T), and B. fumarioli (JCM 21708T) were 36.3%, 30.3%, and 25.3%, respectively. On the basis of physiological, genetic and biochemical data, strain YT-3T represented a novel species of the genus Bacillus, for which the name Bacillus ferrooxidans sp. nov was proposed. The type strain is YT-3T (= KCTC 33875T = CCTCC AB 2017049T).