title: Characterization of Roseomonas and Nocardioides spp. for arsenic transformation.
abstract: The metalloid arsenic predominantly exists in the arsenite [As(III)] and arsenate [As(V)]. These two forms are respectively oxidized and reduced by microbial redox processes. This study was designed to bioprospect arsenic tolerating bacteria from Lonar lake and to characterize their arsenic redoxing ability. Screening of sixty-nine bacterial species isolated from Lonar lake led to identification of three arsenic-oxidizing and seven arsenic-reducing species. Arsenite oxidizing isolate Roseomonas sp. L-159a being closely related to Roseomonas cervicalis ATCC 49957 oxidized 2mM As(III) in 60h. Gene expression of large and small subunits of arsenite oxidase respectively showed 15- and 17-fold higher expression. Another isolate Nocardioides sp. L-37a formed a clade with Nocardioides ghangwensis JC2055, exhibited normal growth with different carbon sources and pH ranges. It reduced 2mM As(V) in 36h and showed constitutive expression of arsenate reductase which increased over 4-fold upon As(V) exposure. Genetic markers related to arsenic transformation were identified and characterized from the two isolates. Moderate resistance against the arsenicals was exhibited by the two isolates in the range of 1-5mM for As(III) and 1-200mM for As(V). Altogether we provide multiple evidences to indicate that Roseomonas sp. and Nocardioides sp. exhibited arsenic transformation ability.
authors: Department of Chemistry, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, Maharashtra, India.
authors: Aditi V
authors: AV
authors: Bagade
authors: Department of Chemistry, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, Maharashtra, India.
authors: Sachin P
authors: SP
authors: Bachate
authors: Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India.
authors: Bhushan B
authors: BB
authors: Dholakia
authors: Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, Maharashtra, India.
authors: Ashok P
authors: AP
authors: Giri
authors: Department of Chemistry, Savitribai Phule Pune University, Ganeshkhind, Pune 411007, Maharashtra, India. Electronic address: kodam@chem.unipune.ac.in.
authors: Kisan M
authors: KM
authors: Kodam
mesh_terms: D000192:Actinomycetales / Q000235:genetics / Q000378:metabolism*; D053502:Arsenate Reductases / Q000235:genetics / Q000378:metabolism; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D018053:Arsenites / Q000378:metabolism; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D060106:Lakes; D042082:Methylobacteriaceae / Q000235:genetics / Q000378:metabolism*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D012989:Soil Pollutants / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism
chemical_list: D018053:Arsenites; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D010088:Oxidoreductases; C078179:arsenite oxidase; D053502:Arsenate Reductases; C015001:arsenite; D001151:Arsenic
keywords: Arsenate reduction; Arsenic; Arsenite oxidation; Nocardioides sp.; Roseomonas sp.