Novel autotrophic arsenite-oxidizing bacteria isolated from soil and sediments
Novel autotrophic arsenite-oxidizing bacteria isolated from soil and sediments
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DOI：
10.1111/j.1574-6941.2008.00569.x
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发表时间：
2008-11-01
影响因子：
4.2
通讯作者：
Young, Lily Y.
中科院分区：
文献类型：
--
作者：
Garcia-Dominguez, Elizabeth;Mumford, Adam;Young, Lily Y.
砷的氧化被认为是由异养微生物和化学自养微生物共同介导的。建立了增菌培养，以确定在选定的受污染但非极端的环境中是否存在能够将亚砷酸盐As(III)氧化为砷酸盐As(V)的化学自养微生物。分离到3株新的细菌，命名为OL-1、S-1和CL-3，发现它们在好氧条件下能以CO_2/HCO_3-为碳源将10 mM亚砷酸盐氧化为亚砷酸盐。根据16S rRNA基因序列分析，菌株OL-1与嗜水杆菌属的亲缘关系为99%，菌株S-1与硫杆菌的亲缘关系为99%，菌株CL-3与噬氢杆菌的亲缘关系为98%。分离的菌株是兼性自养细菌，分离的菌株在亚砷酸盐以外的不同无机电子供体上的生长表明，这三种细菌对几种硫物种都有很强的选择性，而CL-3也能在氨氮和亚硝酸盐上生长。在菌株CL-3中检测到Rubisco I型(CbbL)基因，在OL-1和S-1中检测到II型(CbbM)基因，支持该菌的自养特性。
Arsenic oxidation is recognized as being mediated by both heterotrophic and chemoautotrophic microorganisms. Enrichment cultures were established to determine whether chemoautotrophic microorganisms capable of oxidizing arsenite As(III) to arsenate As(V) are present in selected contaminated but nonextreme environments. Three new organisms, designated as strains OL-1, S-1 and CL-3, were isolated and found to oxidize 10 mM arsenite to arsenate under aerobic conditions using CO2-bicarbonate (CO2/HCO3-) as a carbon source. Based on 16S rRNA gene sequence analyses, strain OL-1 was 99% most closely related to the genus Ancylobacter, strain S-1 was 99% related to Thiobacillus and strain CL-3 was 98% related to the genus Hydrogenophaga. The isolates are facultative autotrophs and growth of isolated strains on different inorganic electron donors other than arsenite showed that all three had a strong preference for several sulfur species, while CL-3 was also able to grow on ammonium and nitrite. The RuBisCO Type I (cbbL) gene was positively amplified and sequenced in strain CL-3, and the Type II (cbbM) gene was detected in strains OL-1 and S-1, supporting the autotrophic nature of the organisms.