Repository of Research and Investigative Information

Repository of Research and Investigative Information

Kurdistan University of Medical Sciences

Bacillus flexus strain As-12, a new arsenic transformer bacterium isolated from contaminated water resources

(2017) Bacillus flexus strain As-12, a new arsenic transformer bacterium isolated from contaminated water resources. Chemosphere.

Full text not available from this repository.

Official URL:


A total of 14 arsenic-resistant bacteria were isolated from an arsenic-contaminated travertine spring water in the central district of Qorveh county, Kurdistan Province, Iran. One of strains designated As-12 was selected for further investigation because of its ability to transform arsenic. The strain was identified by cultural, morphological and biochemical tests, and 16S rRNA gene sequencing. Finally, the growth characteristics of the isolate were investigated in a chemically defined medium which included varied ranges of environmental factors such as pH, temperature and salinity. Moreover, the resistance of this strain to some heavy metals was evaluated. The bacterium was a Gram-positive, endospore-forming with all other characteristics of the genus Bacillus. It revealed maximum similarity at the 16S rRNA gene level with Bacillus flexus. The optimum growth of the strain was observed at 38 °C, pH 9 and 2 salinity. This strain was resistant to heavy metals such as zinc, chromium, lead, nickel, copper, mercuric and cadmium at concentrations of 15 mM, 15.5 mM, 11.5 mM, 12 mM, 11 mM, 5.5 mM, and 1 mM, respectively. The isolated bacterium was able to reduce As (V) to As (III) (about 28) and oxidize As (III) to As (V) (about 45) after 48 h of incubation at 37 °C. In conclusion, Bacillus flexus strain As-12, was identified as an arsenic transformer, for the first time. © 2016 Elsevier Ltd

Item Type: Article
Keywords: Arsenic; Bacteria; Bacteriology; Bioremediation; Copper; Genes; Groundwater; Heavy metals; RNA; Strain; Water pollution, 16S rRNA gene sequencing; Arsenic-resistant bacteria; Bacillus flexus; Biochemical tests; Contaminated water; Defined mediums; Environmental factors; Growth characteristic, Water resources, arsenic; cadmium; chromium; copper; ground water; lead; mercury; nickel; RNA 16S; zinc; arsenic; bacterial DNA; fatty acid; heavy metal; water pollutant, arsenic; bacterium; bioremediation; biotransformation; concentration (composition); environmental factor; gene expression; genetic analysis; heavy metal; spring water; travertine; water resource, arsenic transformer bacterium; Article; Bacillus; Bacillus flexus; bacterial growth; bacterial strain; bacterium isolation; bioremediation; environmental factor; gene sequence; Gram positive bacterium; minimum inhibitory concentration; nonhuman; pH; salinity; sample; temperature; water contamination; water supply; analysis; antibiotic resistance; Bacillus; chemistry; DNA base composition; DNA sequence; drug effects; genetics; growth, development and aging; Iran; microbial sensitivity test; microbiology; phylogeny; river; water pollutant; water supply, Iran; Kordestan Iran, Bacillus (bacterium); Bacillus flexus; Bacteria (microorganisms); Posibacteria, Arsenic; Bacillus; Base Composition; Biodegradation, Environmental; DNA, Bacterial; Drug Resistance, Bacterial; Fatty Acids; Iran; Metals, Heavy; Microbial Sensitivity Tests; Phylogeny; Rivers; RNA, Ribosomal, 16S; Salinity; Sequence Analysis, DNA; Water Pollutants, Chemical; Water Resources
Page Range: pp. 636-641
Journal or Publication Title: Chemosphere
Volume: 169
Publisher: Elsevier Ltd
Identification Number: 10.1016/j.chemosphere.2016.11.129
ISSN: 00456535
Depositing User: مهندس مهدی شریفی

Actions (login required)

View Item View Item