title: Arsenite oxidation by a facultative chemolithotrophic bacterium SDB1 isolated from mine tailing.
abstract: An arsenite (As[III])-oxidizing bacterium, SDB1, was isolated from mine tailing collected from the Sangdong mine area in Korea and showed chemolithotrophic growth on As[III] and CO(2) as the respective electron and carbon sources. SDB1 is Gram-negative, rod-shaped, and belongs to the Sinorhizobium-Ensifer branch of alpha-Proteobacteria. Growth and As[III] oxidation was enhanced significantly by the presence of yeast extract (0.005%) in minimal salt medium containing 5 mM As[III]; decreasing the doubling time from 9.8 to 2.1 h and increasing the As [III] oxidation rate from 0.014 to 0.349 pmol As [III] oxidized cell(-1) h(-1). As[III] oxidation nearly stopped at pH around 4 and should be performed at pH 7 approximately 8 to be most effective. SDB1 was immobilized in calcium-alginate beads and the oxidation capacity was investigated. Specific As[III] oxidation rates obtained with SDB1 (10.1-33.7 mM As[III] oxidized g(-1) dry cell h(-1)) were 10 approximately 16-times higher than those reported previously with a heterotrophic bacterial strain (Simeonova et al., 2005). The stability and reusability of immobilized SDB1 strongly suggested that the immobilized SDB1 cell System can make the As[III] oxidation process technically and economically feasible in practical applications.
authors.affiliation: Department of Environmental Engineering and Biotechnology, Myongji University, Yongin 449-728, Republic of Korea.
authors.forename: Rovimar T
authors.initials: RT
authors.lastname: Lugtu
authors.forename: Sung-Chan
authors.initials: SC
authors.lastname: Choi
authors.forename: Young-Sook
authors.initials: YS
authors.lastname: Oh
mesh_terms: D018053:Arsenites / Q000378:metabolism*; D019149:Bioreactors; D002245:Carbon Dioxide / Q000378:metabolism; D018914:Cells, Immobilized; D003470:Culture Media / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010461:Peptones / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D056910:Republic of Korea; D017422:Sequence Analysis, DNA; D020579:Sinorhizobium / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D018053:Arsenites; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D010461:Peptones; D012336:RNA, Ribosomal, 16S; D002245:Carbon Dioxide; C015001:arsenite