Arsenic-resistant proteobacterium from the phyllosphere of arsenic-hyperaccumulating fern (Pteris vittata L.) reduces arsenate to arsenite

• Published in: Canadian journal of microbiology Vol. 52; no. 7; pp. 695 - 700
• Main Authors: Rathinasabapathi, B, Raman, S.B, Kertulis, G, Ma, L
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.07.2006; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Antimony; arsenate; Arsenates - metabolism; Arsenic; Arsenic - chemistry; Arsenic - metabolism; Arsenic - pharmacokinetics; arsenite; Arsenites; Bacteria; Bacteriology; Biodegradation, Environmental; Biological and medical sciences; Cells; Chromium; Drug Resistance, Bacterial; E coli; Environmental Pollutants - metabolism; Ferns; ferns and fern allies; Fresh Water - microbiology; Fundamental and applied biological sciences. Psychology; genes; hyperaccumulators; metal tolerance; Microbiology; Miscellaneous; Molecular Sequence Data; nucleotide sequences; Oxidation-Reduction; Oxides - chemistry; phyllosphere; Phylogeny; Proteobacteria; Proteobacteria - isolation & purification; Proteobacteria - metabolism; Pseudomonas; Pteris - chemistry; Pteris - microbiology; Pteris vittata; reduction; ribosomal DNA; ribosomal RNA; RNA, Ribosomal, 16S - genetics; RNA, Ribosomal, 16S - isolation & purification; Staphylococcus infections; Studies; Canada; Pseudomonadales; Resistance; Pollutant; Plant; Arsenic; Arsenates; Phyllosphere; Bacteria; Pseudomonadaceae; Pteridophyta; Pseudomonas; Filicineae
• ISSN: 0008-4166; 1480-3275
• DOI: 10.1139/w06-017

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.Key words: arsenate reduction, arsenic bioremediation, Pseudomonas saccharophila, Variovorax paradoxus, Pteris vittala.