Ecophysiology and geochemistry of microbial arsenic oxidation within a high arsenic, circumneutral hot spring system of the Alvord Desert
Ecophysiology and geochemistry of microbial arsenic oxidation within a high arsenic, circumneutral hot spring system of the Alvord Desert
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DOI：
10.1111/j.1574-6941.2008.00456.x
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发表时间：
2008-04-01
影响因子：
4.2
通讯作者：
Magnuson, Timothy S.
中科院分区：
文献类型：
--
作者：
Connon, Stephanie A.;Koski, Angie K.;Magnuson, Timothy S.
由于微生物具有驱动砷循环的潜力，并显著影响自然富砷或人为砷污染环境的地球化学，因此微生物对砷的代谢已引起人们的极大兴趣。位于俄勒冈州东南部的阿尔沃德温泉是一种近中性温泉，平均砷浓度为4.5mgL-1(60亩M)。水文地球化学分析表明，沿流入阿尔沃德温泉的溪流通道有明显的亚砷酸盐氧化、pH升高和温度下降。三条流道的pH值和温度的动态范围分别为6.76-7.06℃和69.5-78.2℃。生物膜样品表现为(III)异位氧化。对稀疏上游生物膜的16S rRNA基因研究表明，硫氢细菌、Thermus和Thermocrinis是优势细菌。茂盛的下游生物膜群落包括这三个相同的组，但与未培养的OP10细菌门、未培养的拟杆菌和未培养的分支相关的序列更加多样化。采用人工温泉培养基分离亚砷酸盐氧化菌，经16S rRNA基因分析，得到一株与水生黄热菌亲缘关系密切的菌株A03C。因此，本研究证明了细菌在温度、pH和As(III)：As(V)的地球化学梯度上的多样性，并为Alvord温泉系统内的微生物亚砷酸盐氧化提供了证据。
Microbial metabolism of arsenic has gained considerable interest, due to the potential of microorganisms to drive arsenic cycling and significantly influence the geochemistry of naturally arsenic-rich or anthropogenically arsenic-polluted environments. Alvord Hot Spring in southeastern Oregon is a circumneutral hot spring with an average arsenic concentration of 4.5 mg L-1 (60 mu M). Hydrogeochemical analyses indicated significant arsenite oxidation, increased pH and decreased temperature along the stream channels flowing into Alvord Hot Spring. The dynamic range of pH and temperature over the length of three stream channels were 6.76-7.06 and 69.5-78.2 degrees C, respectively. Biofilm samples showed As(III) oxidation ex situ. 16S rRNA gene studies of sparse upstream biofilm indicated a dominance of bacteria related to Sulfurihydrogenibium, Thermus, and Thermocrinis. The lush downstream biofilm community included these same three groups but was more diverse with sequences related to uncultured OP10 bacterial phylum, uncultured Bacteroidetes, and an uncultured clade. Isolation of an arsenite oxidizer was conducted with artificial hot spring medium and yielded the isolate A03C, which is closely related to Thermus aquaticus based on 16S rRNA gene analysis. Thus, this study demonstrated the bacterial diversity along geochemical gradients of temperature, pH and As(III): As(V), and provided evidence of microbial arsenite oxidation within the Alvord Hot Spring system.