Microbes-Assisted Arsenate Reduction Activity in Bangladesh Drinking Water Wells as Revealed by Enrichment Cultivation
Microbes-Assisted Arsenate Reduction Activity in Bangladesh Drinking Water Wells as Revealed by Enrichment Cultivation
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DOI：
10.1080/01490451.2022.2133195
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发表时间：
2022-11
影响因子：
2.3
通讯作者：
Z. Hassan;M. Braster;W. Röling;H. Westerhoff
中科院分区：
文献类型：
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作者：
Z. Hassan;M. Braster;W. Röling;H. Westerhoff
砷还原微生物可将砷运移到地下水中。系统发育DNA序列信息不能专门用于推断砷酸盐还原，因为斑点同源性可能无法转化为生化活性。我们在此开发了一种基于培养的宏基因组策略来推断实际活动：我们补充了一项不依赖于培养的微生物群落调查，该调查涵盖了孟加拉国22口砷污染的饮用水井，并对厌氧砷酸盐还原剂的富集进行了表征。所有调查样品均显示微生物砷酸盐还原活性。富集的微生物群落在富集区内和富集之间具有系统发育多样性。该富集还揭示了物种：除还原砷的硫螺旋藻菌株NP4、b10和异化还原铁的地杆菌物种外，还原砷的富集物所含的16S rRNA基因序列与decchloromonas sp.、Azonexus fungiphilus、Youngiibacter fragile、产甲烷原核生物和fususbacter sp.最接近。富集的砷酸还原酶基因（arrA）序列与已知的砷酸还原硫螺旋藻（sulfurrospirillum barnesii）序列最接近。本研究弥合了培养独立分析和培养依赖分析之间的知识鸿沟。阐明了农村饮水井水中砷的迁移和再分配机制，作为生物修复和有害活动之间的平衡。已确定的可能异化的砷酸盐和铁还原微生物构成砷生物修复的风险。适当的宏基因组和动态分析应该有助于设计和维持更安全、有效的生物修复。
Abstract Arsenate-reducing microorganisms may mobilize arsenic into groundwater. Phylogenetic DNA sequence information cannot exclusively be used to infer arsenate reduction, as the spotted homologies may not translate to biochemical activities. We here develop a cultivation-based metagenomic strategy for inferring actual activities: we complement a cultivation-independent microbial community survey covering 22 arsenic-contaminated drinking water wells in Bangladesh, with the characterization of enrichments of anaerobic arsenate reducers. All investigated samples revealed microbial arsenate reduction activity. The enriched microbial communities were phylogenetically diverse within and between the enrichments. The enrichment also unveiled species: the arsenate-reducing enrichments held 16S rRNA gene sequences closest to Dechloromonas sp., Azonexus fungiphilus, Youngiibacter fragile, Methanogenic prokaryote and Fusibacter sp., in addition to arsenate-reducing Sulfurospirillum strains NP4, b10 and dissimilatory iron-reducing Geobacter species. The enriched arsenate reductase gene (arrA) sequences were closest to sequences in known arsenate reducing Sulfurospirillum barnesii. This study bridges the knowledge gap between cultivation-independent and cultivation-dependent analyses. It clarifies the mechanism for arsenic mobilization and redistribution in rural drinking water wells, as a balance between bioremediation and harmful activities. The identified, potentially dissimilatory arsenate and iron-reducing microbes, constitute a risk for arsenic bioremediation. Appropriate metagenomic and dynamic analyses should help design and maintain safer, effective bioremediation.