Bacillus arsenicoselenatis, sp. nov., and Bacillus selenitireducens, sp. nov. : two haloalkaliphiles from Mono Lake, California that respire oxyanions of selenium and arsenic

• Published in: Archives of microbiology Vol. 171; no. 1; pp. 19 - 30
• Main Authors: BLUM, J. S, BINDI, A. B, BUZZELLI, J, STOLZ, J. F, OREMLAND, R. S
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-12-1998; Berlin
• Subjects: Anaerobiosis; Animal, plant and microbial ecology; Arsenic - metabolism; Bacillus - classification; Bacillus - growth & development; Bacillus - metabolism; Bacillus - ultrastructure; Bacillus arsenicoselenatis; Bacillus selenitireducens; Bacteriology; Biological and medical sciences; California; Coculture Techniques; Fundamental and applied biological sciences. Psychology; Glucose - metabolism; Gram-Positive Bacteria - classification; Gram-Positive Bacteria - growth & development; Gram-Positive Bacteria - metabolism; Gram-Positive Bacteria - ultrastructure; Lactic Acid - metabolism; Microbial ecology; Microbiology; Microscopy, Electron; Phylogeny; RNA, Ribosomal, 16S - analysis; Selenium - metabolism; Soil Microbiology; Systematics; USA, California, Mono L; Various environments (extraatmospheric space, air, water); California; USA, California; Anaerobiosis; Brackish water environment; Microorganism growth; Taxonomy; Alkalophily; Genotype; Phylogeny; Bacillaceae; Arsenic V; Characterization; Phenotype; Bacillales; Halophily; Morphology; Bacillus; Bacteria; Isolation; New species; Selenium IV; Cell respiration
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/s002030050673

Two gram-positive anaerobic bacteria (strains E1H and MLS10) were isolated from the anoxic muds of Mono Lake, California, an alkaline, hypersaline, arsenic-rich water body. Both grew by dissimilatory reduction of As(V) to As(III) with the concomitant oxidation of lactate to acetate plus CO2. Bacillus arsenicoselenatis (strain E1H) is a spore-forming rod that also grew by dissimilatory reduction of Se(VI) to Se(IV). Bacillus selenitireducens (strain MLS10) is a short, non-spore-forming rod that grew by dissimilatory reduction of Se(IV) to Se(0). When the two isolates were cocultured, a complete reduction of Se(VI) to Se(0) was achieved. Both isolates are alkaliphiles and had optimal specific growth rates in the pH range of 8.5-10. Strain E1H had a salinity optimum at 60 g l-1 NaCl, while strain MLS10 had optimal growth at lower salinities (24-60 g l-1 NaCl). Both strains have limited abilities to grow with electron donors and acceptors other than those given above. Strain MLS10 demonstrated weak growth as a microaerophile and was also capable of fermentative growth on glucose, while strain E1H is a strict anaerobe. Comparative 16S rRNA gene sequence analysis placed the two isolates with other Bacillus spp. in the low G+C gram-positive group of bacteria.