title: Arsenic-resistant proteobacterium from the phyllosphere of arsenic-hyperaccumulating fern (Pteris vittata L.) reduces arsenate to arsenite.
abstract: An arsenic-resistant bacterium, AsRB1, was isolated from the fronds of Pteris vittata grown in a site contaminated with copper chromium arsenate. The bacterium exhibited resistance to arsenate, arsenite, and antimony in the culture medium. AsRB1, like Pseudomonas putida, grew on MacConkey and xylose-lactose-desoxycholate agars and utilized citrate but, unlike P. putida, was positive for indole test and negative for oxidase test. A phylogenetic analysis of the 16S rRNA gene showed that AsRB1 is a proteobacterium of the beta subclass, related to Pseudomonas saccharophila and Variovorax paradoxus. Following an exogenous supply of arsenate, most arsenic occurred as arsenite in the medium and the cell extracts, suggesting reduction and extrusion of arsenic as the mechanism for arsenic resistance in AsRB1.
authors.affiliation: Horticultural Sciences, Department of Florida, Gainesville, FL 32611-0690, USA. brath@mail.ifas.ufl.edu
authors.forename: Bala
authors.initials: B
authors.lastname: Rathinasabapathi
authors.forename: Suresh Babu
authors.initials: SB
authors.lastname: Raman
authors.forename: Gina
authors.initials: G
authors.lastname: Kertulis
authors.forename: Lena
authors.initials: L
authors.lastname: Ma
mesh_terms: D001149:Arsenates / Q000378:metabolism; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics; D018053:Arsenites; D001673:Biodegradation, Environmental; D024881:Drug Resistance, Bacterial; D004785:Environmental Pollutants / Q000378:metabolism; D005618:Fresh Water / Q000382:microbiology*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D010802:Phylogeny; D020560:Proteobacteria / Q000302:isolation & purification / Q000378:metabolism*; D032495:Pteris / Q000737:chemistry / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000302:isolation & purification
chemical_list: D001149:Arsenates; D018053:Arsenites; D004785:Environmental Pollutants; D010087:Oxides; D012336:RNA, Ribosomal, 16S; C015001:arsenite; D001151:Arsenic; C025657:arsenic acid