Comamonas terrae sp. nov., an arsenite-oxidizing bacterium isolated from agricultural soil in Thailand

Abstract

The genus Comamonas belonging to the family Comamonadaceae of the class Beta-Proteobacteria was proposed by De Vos et al. (1985) after a polyphasic study. In the genus Comamonas, 13 species have been described at the time of writing, C. aquatica, C. badia, C. denitrifi cans, C. kerstersii, C. koreensis, C. nitrativorans, C. odontotermitis, C. terrigena (type species), C. testosteroni, C. composti, C. zonglianii, C. thiooxidans, and C. granuli (Chang et al., 2002; Chou et al., 2007; De Vos et al.,1985; Etchebehere et al., 2001; Gumaelius et al., 2001; Kim et al., 2008; Narayan et al., 2010; Tago and Yokota, 2004; Tamaoka et al., 1987; Wauters et al., 2003; Young et al., 2008; Yu et al., 2011). Comamonas strains have been isolated from a phenol-activated-sludge process and soils contaminated with heavy metals (Kanazawa and Mori, 1996; Watanabe et al., 1999). During the course of screening of a high arsenic resistant bacteria from arsenic contaminated soils in Thailand, Comamonas strain A3-3T was isolated and reported (Chitpirom et al., 2009). This paper, we propose Comamonas terrae sp. nov. to strain A3-3T. Strain A3-3T, an arsenite oxidizing bacterium was isolated from the arsenic contaminated soil samples (< 5 mg/kg) in central of Thailand by an enrichment culture method using 0.1 g/L sodium arsenite (Chitpirom et al., 2009). The MICs for arsenite and arsenate of the A3-3T isolate were 40 and 400 mM, respectively (Chitpirom et al., 2009). The capability to oxidize arsenite (+III) to arsenate (+V) of A3-3T was tested in situ by X-ray absorption near edge structure (XANES) analysis. The strain was phenotypically characterized J. Gen. Appl. Microbiol., 58, 245‒251 (2012)