Submitted to: National Center for Biotechnology Information (NCBI)
Publication Type: Other
Publication Acceptance Date: March 14, 2007
Publication Date: September 24, 2007
Citation: Hunter, W.J. 2007. Rhizobium sp. strain BN4 (a selenium oxyanion-reducing bacterium) 16S rRNA gene complete sequence. National Center for Biotechnology Information (NCBI). Technical Abstract: This study used 1482 base pair 16S rRNA gene sequence methods in conjunction with other biochemical and morphological studies to confirm the identification of a bacterium (refer to as the BN4 strain) as a Rhizobium sp. The 16S rRNA gene sequence places it with the Rhizobium clade that includes R. daejeonense, R. giardinii, R. undicola, R. larrymoorei, R. radiobacter, R. rubi, and R. vitis with R. radiobacter (syn Agrobacterium tumefaciens) being its closest relative. The strain’s phenotypic and biochemical characteristics were consistent with its placement with this group of bacteria. The strain is of interest because of its ability to reduce selenite to elemental red selenium. The isolate was obtained from a biobarrier that contained vegetable oil as an electron donor and that was supplied with water contaminated with selenate. Selenite in small amounts is a nutrient but in large amounts it is toxic and ingestion of excessive amounts can injure the nervous system. Procedures are needed that can remove excess selenite and selenate from ground and irrigation waters. Biological methods that use microorganisms are likely to be the least expensive approach for removing these compounds from groundwater and as part of this effort it is important that microorganisms be isolated, characterized, and identified that have the ability to sequester selenite and selenate from ground and surface waters. This organism, or perhaps its enzymes or DNA, might be of future use for the remediation of waters containing selenate or selenite.