Enrichment and isolation of Bacillus beveridgei sp. nov., a facultative anaerobic haloalkaliphile from Mono Lake, California, that respires oxyanions of tellurium, selenium, and arsenic

• Published in: Extremophiles : life under extreme conditions 2009-07, Vol.13 (4), p.695-705
• Main Authors: Baesman, S. M, Stolz, J. F, Kulp, T. R, Oremland, Ronald S
• Format: Article
• Language: English
• Subjects: Alkaliphile ecology, systematics; Alkaliphiles: systematics, ecology, phylogeny; Anaerobic bacteria; Anions; Arsenic; Arsenic - metabolism; Bacillus - metabolism; Bacillus - physiology; Bacteria; Bacteriology; Biochemistry; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biomedical and Life Sciences; Biotechnology; Biotechnology - methods; California; Carbon dioxide; Ecology; Fundamental and applied biological sciences. Psychology; Genetics; Geologic Sediments; Halophile: ecology, biotechnology, phylogeny, genetics, taxonomy, enzymes; Isolation and characterization; Isolation and description; Lake sediments; Lakes; Life Sciences; Metal oxidation and reduction; Metals; Microbial Ecology; Microbiology; Microscopy, Electron, Scanning - methods; Mission oriented research; Original Paper; Oxygen - chemistry; Phylogeny; Salts - chemistry; Sediments; Selenium; Selenium - metabolism; Slurries; Space life sciences; Systematics; Tellurium; Tellurium - metabolism; Time Factors; Water
• ISSN: 1431-0651; 1433-4909
• DOI: 10.1007/s00792-009-0257-z

Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/Te(IV) agar plates, followed by repeated streaking and picking. The isolate, strain MLTeJB, grew in aqueous Te(IV)-medium if provided with a small amount of sterile solid phase material (e.g., agar plug; glass beads). Strain MLTeJB grew at high concentrations of Te(IV) (~8 mM) by oxidizing lactate to acetate plus formate, while reducing Te(IV) to Te(0). Other electron acceptors that were found to sustain growth were tellurate, selenate, selenite, arsenate, nitrate, nitrite, fumarate and oxygen. Notably, growth on arsenate, nitrate, nitrite and fumarate did not result in the accumulation of formate, implying that in these cases lactate was oxidized to acetate plus CO₂. Strain MLTeJB is a low G + C Gram positive motile rod with pH, sodium, and temperature growth optima at 8.5-9.0, 0.5-1.5 M, and 40°C, respectively. The epithet Bacillus beveridgei strain MLTeJBT is proposed.