Diversity and characterization of sulfate-reducing bacteria in groundwater at a uranium mill tailings site
Diversity and characterization of sulfate-reducing bacteria in groundwater at a uranium mill tailings site
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DOI：
10.1128/aem.67.7.3149-3160.2001
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发表时间：
2001-07-01
影响因子：
4.4
通讯作者：
White, DC
中科院分区：
文献类型：
--
作者：
Chang, YJ;Peacock, AD;White, DC
微生物介导的还原和固定化U（VI）到U（TV）在铀污染场地的自然衰减和加速生物修复中发挥着作用。为了实现生物修复潜力和准确预测自然衰减，重要的是要首先了解这些网站的微生物多样性。本文对美国新墨西哥州希普洛克铀尾矿库污染地下水中硫酸盐还原菌（SRB）的分布进行了研究。两个文化独立的分析：PCR扩增的异化亚硫酸盐还原酶（DSR）基因片段和磷脂脂肪酸（PLFA）生物标志物分析的克隆文库测序。DSR序列之间的显着多样性被揭示，包括从F-变形菌，革兰氏阳性菌，和Nitrospira司的序列。PLFA分析检测到至少52个不同的中链分支饱和PLFA，并且包括高比例的10 me 16：0，脱硫肠状菌和脱硫肠状菌样序列是检测到的最显性DSR基因。属于F-变形菌门中的硫酸盐还原菌的那些主要从低铀（小于或等于302 ppb）样品中回收。一个类似脱硫肠状菌的序列簇压倒性地控制了高铀（> 1，500 ppb）位点。Logistic回归分析表明，铀浓度对这一序列群的优势度有显著影响（P = 0.0001），这种强相关性表明脱硫肠状菌对高浓度铀具有显著的耐受性和适应性，并表明该生物体可能参与了铀的自然衰减。脱硫肠状菌在铀污染环境中的原位活性水平及其与其他硫酸盐还原菌和其他功能基团的活性的比较应该是未来研究的重要领域。
Microbially mediated reduction and immobilization of U(VI) to U(TV) plays a role in both natural attenuation and accelerated bioremediation of uranium contaminated sites. To realize bioremediation potential and accurately predict natural attenuation, it is important to first understand the microbial diversity of such sites. In this paper, the distribution of sulfate-reducing bacteria (SRB) in contaminated groundwater associated with a uranium mill tailings disposal site at Shiprock, N.Mex,, was investigated. Two culture-independent analyses were employed: sequencing of clone libraries of PCR-amplified dissimilatory sulfite reductase (DSR) gene fragments and phospholipid fatty acid (PLFA) biomarker analysis. A remarkable diversity among the DSR sequences was revealed, including sequences from F-Proteobacteria, gram-positive organisms, and the Nitrospira division. PLFA analysis detected at least,52 different mid-chain-branched saturate PLFA and included a high proportion of 10me16:0, Desulfotomaculum and Desulfotomaculum-like sequences were the most dominant DSR genes detected. Those belonging to SRB within F-Proteobacteria were mainly recovered from low-uranium (less than or equal to 302 ppb) samples. One Desulfotomaculum like sequence cluster overwhelmingly dominated high-U (>1,500 ppb) sites. Logistic regression showed a significant influence of uranium concentration over the dominance of this cluster of sequences (P = 0.0001), This strong association indicates that Desulfotomaculum has remarkable tolerance and adaptation to high levels of uranium and suggests the organism's possible involvement in natural attenuation of uranium. The in situ activity level of Desulfotomaculum in uranium-contaminated environments and its comparison to the activities of other SRB and other functional groups should be an important area for future research.