Oxidation of arsenite by two β-proteobacteria isolated from soil
Oxidation of arsenite by two β-proteobacteria isolated from soil
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DOI：
10.1007/s00253-011-3606-7
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发表时间：
2012-03-01
影响因子：
5
通讯作者：
Kodam, Kisan M.
中科院分区：
文献类型：
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作者：
Bachate, Sachin P.;Khapare, Rashmi M.;Kodam, Kisan M.
从园林土壤中分离到2株异养As（III）氧化细菌SPB-24和SPB-31。基于16S rRNA基因序列分析，菌株SPB-24与博德特拉属亲缘关系较近，菌株SPB-31与无色杆菌属亲缘关系最近。两株菌株均表现出较高的As（III）抗性（SPB-24为15 mM， SPB-31为40 mM）和As(V)抗性（两株菌株均为300 mM）。菌株SPB-24和SPB-31在最小培养基中氧化5 mM As(III)，氧化速率分别为554和558 μ M h（-1）。两株菌株在较宽的pH和温度范围内洗涤细胞氧化As(III)，两株菌株的最适pH为6，温度为42A℃。洗涤细胞的As（III）氧化动力学表明，SPB-24的K (m)和V （max）值分别为41.7 μ m和1166 μ m h(-1)， SPB-31的K (m)和V （max）值分别为52 μ m和1186 μ m h（-1）。在少量碳源存在的情况下，菌株表现出较高的As（III）氧化速率和较高的亚砷酸氧化酶活性。菌株抗高浓度砷和氧化As（III）的能力是迄今为止报道的最高的，这使它们成为砷污染环境生物修复的潜在候选者。
Two heterotrophic As(III)-oxidizing bacteria, SPB-24 and SPB-31 were isolated from garden soil. Based on 16S rRNA gene sequence analysis, strain SPB-24 was closely related to genus Bordetella, and strain SPB-31 was most closely related to genus Achromobacter. Both strains exhibited high As(III) (15 mM for SPB-24 and 40 mM for SPB-31) and As(V) (> 300 mM for both strains) resistance. Both strains oxidized 5 mM As(III) in minimal medium with oxidation rate of 554 and 558 mu M h(-1) for SPB-24 and SPB-31, respectively. Washed cells of both strains oxidized As(III) over broad pH and temperature range with optimum pH 6 and temperature 42A degrees C for both strains. The As(III) oxidation kinetic by washed cells showed K (m) and V (max) values of 41.7 mu M and 1,166 mu M h(-1) for SPB-24, 52 mu M and 1,186 mu M h(-1) for SPB-31. In the presence of minimal amount of carbon source, the strains showed high As(III) oxidation rate and high specific arsenite oxidase activity. The ability of strains to resist high concentration of arsenic and oxidize As(III) with highest rates reported so far makes them potential candidates for bioremediation of arsenic-contaminated environment.