Switzer Blum J, Burns Bindi A, Buzzelli J, Stolz J F, Oremland R S
US Geological Survey, ms 480, 345 Middlefield Road, Menlo Park, CA 94025, USA.
Arch Microbiol. 1998 Dec;171(1):19-30. 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.
从加利福尼亚州莫诺湖的缺氧泥中分离出两种革兰氏阳性厌氧菌（菌株E1H和MLS10），莫诺湖是一个碱性、高盐、富含砷的水体。二者均通过将As(V)异化还原为As(III)并伴随将乳酸氧化为乙酸和CO₂来生长。砷硒还原芽孢杆菌（菌株E1H）是一种形成芽孢的杆菌，也通过将Se(VI)异化还原为Se(IV)来生长。亚硒酸盐还原芽孢杆菌（菌株MLS10）是一种短的、不形成芽孢的杆菌，通过将Se(IV)异化还原为Se(0)来生长。当将这两种分离株共培养时，可实现将Se(VI)完全还原为Se(0)。这两种分离株均为嗜碱菌，在pH 8.5 - 10范围内具有最佳比生长速率。菌株E _{1}H在NaCl浓度为60 g l⁻¹时具有最佳盐度，而菌株MLS10在较低盐度（24 - 60 g l⁻¹ NaCl）下生长最佳。除上述电子供体和受体外，这两种菌株利用其他电子供体和受体生长的能力有限。菌株MLS10作为微需氧菌生长较弱，也能够在葡萄糖上进行发酵生长，而菌株E1H是严格厌氧菌。16S rRNA基因序列比较分析将这两种分离株与其他芽孢杆菌属细菌归为低G+C革兰氏阳性菌组。
