Microbial Community Analysis Provides Insights into the Effects of Tetrahydrofuran on 1,4-Dioxane Biodegradation
Microbial Community Analysis Provides Insights into the Effects of Tetrahydrofuran on 1,4-Dioxane Biodegradation
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DOI：
10.1128/aem.00244-19
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发表时间：
2019-03
影响因子：
4.4
通讯作者：
Yi Xiong;O. U. Mason;A. Lowe;Chao Zhou;Gang Chen;Youneng Tang
中科院分区：
文献类型：
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作者：
Yi Xiong;O. U. Mason;A. Lowe;Chao Zhou;Gang Chen;Youneng Tang
1，4-二氧六环（二氧六环）广泛存在于地下水中，对人类具有致癌性，近年来引起了人们的极大关注。高级氧化工艺可以有效去除二氧六环，但需要较高的能耗和运行成本。生物去除二氧杂环己烷是特别感兴趣的，因为一些细菌能够以低能量成本矿化二氧杂环己烷。虽然二氧六环通常被认为是生物降解的难降解物，但超过20种细菌可以降解二氧六环作为唯一电子供体底物或二次电子供体底物。在后一种情况下，四氢呋喃（THF）通常被研究为主要的电子供体底物。先前的工作已经表明，THF在低THF浓度下促进二氧六环降解，但在高THF浓度下抑制二氧六环降解。我们的工作扩大了以前的工作，机械检查THF对二氧六环降解的微生物群落的背景下的影响。摘要四氢呋喃（THF）是一种能够诱导1，4-二氧六环（二氧六环）生物降解的新型污染物，但其影响二氧六环在微生物群落中生物降解的机制尚不清楚。为了填补这一知识空白，随着时间的推移，使用16 S rRNA基因扩增子测序和功能基因定量PCR检测，在合成培养基和垃圾渗滤液的微宇宙实验中的微生物群落结构的变化进行了研究。正在测试的首要假设是，THF通过增加财团中的二恶烷降解细菌的丰度来促进二恶烷的生物降解。数据显示，在合成培养基的实验中，加入THF显著增加了假诺卡氏菌（一种具有几个代表性的属，可以在二氧杂环己烷和THF上生长）和红色红球菌（一种可以使用THF作为主要生长底物同时共代谢二氧杂环己烷的物种）的丰度。然而，在垃圾渗滤液的类似实验中，只有R。明显富集了橡胶。当THF浓度高于二氧六环浓度时，THF竞争性抑制二氧六环降解，因为二氧六环降解可以忽略不计，而二氧六环降解细菌和相应的THF/二氧六环单加氧酶基因拷贝增加了几个数量级。重要性1，4-二氧六环（二氧六环）广泛存在于地下水中，对人类具有致癌性，近年来引起了人们的极大关注。高级氧化工艺可以有效去除二氧六环，但需要较高的能耗和运行成本。生物去除二氧杂环己烷是特别感兴趣的，因为一些细菌能够以低能量成本矿化二氧杂环己烷。虽然二氧六环通常被认为是生物降解的难降解物，但超过20种细菌可以降解二氧六环作为唯一电子供体底物或二次电子供体底物。在后一种情况下，四氢呋喃（THF）通常被研究为主要的电子供体底物。先前的工作已经表明，THF在低THF浓度下促进二氧六环降解，但在高THF浓度下抑制二氧六环降解。我们的工作扩大了以前的工作，机械检查THF对二氧六环降解的微生物群落的背景下的影响。
Widespread in groundwater and carcinogenic to humans, 1,4-dioxane (dioxane) is attracting significant attention in recent years. Advanced oxidation processes can effectively remove dioxane but require high energy consumption and operation costs. Biological removal of dioxane is of particular interest due to the ability of some bacteria to mineralize dioxane at a low energy cost. Although dioxane is generally considered recalcitrant to biodegradation, more than 20 types of bacteria can degrade dioxane as the sole electron donor substrate or the secondary electron donor substrate. In the latter case, tetrahydrofuran (THF) is commonly studied as the primary electron donor substrate. Previous work has shown that THF promotes dioxane degradation at a low THF concentration but inhibits dioxane degradation at a high THF concentration. Our work expanded on the previous work by mechanically examining the effects of THF on dioxane degradation in a microbial community context. ABSTRACT Tetrahydrofuran (THF) is known to induce the biodegradation of 1,4-dioxane (dioxane), an emerging contaminant, but the mechanisms by which THF affects dioxane biodegradation in microbial communities are not well understood. To fill this knowledge gap, changes in the microbial community structure in microcosm experiments with synthetic medium and landfill leachate were examined over time using 16S rRNA gene amplicon sequencing and functional gene quantitative PCR assays. The overarching hypothesis being tested was that THF promoted dioxane biodegradation by increasing the abundance of dioxane-degrading bacteria in the consortium. The data revealed that in experiments with synthetic medium, the addition of THF significantly increased the abundance of Pseudonocardia, a genus with several representatives that can grow on both dioxane and THF, and of Rhodococcus ruber, a species that can use THF as the primary growth substrate while cometabolizing dioxane. However, in similar experiments with landfill leachate, only R. ruber was significantly enriched. When the THF concentration was higher than the dioxane concentration, THF competitively inhibited dioxane degradation since dioxane degradation was negligible, while the dioxane-degrading bacteria and the corresponding THF/dioxane monooxygenase gene copies increased by a few orders of magnitude. IMPORTANCE Widespread in groundwater and carcinogenic to humans, 1,4-dioxane (dioxane) is attracting significant attention in recent years. Advanced oxidation processes can effectively remove dioxane but require high energy consumption and operation costs. Biological removal of dioxane is of particular interest due to the ability of some bacteria to mineralize dioxane at a low energy cost. Although dioxane is generally considered recalcitrant to biodegradation, more than 20 types of bacteria can degrade dioxane as the sole electron donor substrate or the secondary electron donor substrate. In the latter case, tetrahydrofuran (THF) is commonly studied as the primary electron donor substrate. Previous work has shown that THF promotes dioxane degradation at a low THF concentration but inhibits dioxane degradation at a high THF concentration. Our work expanded on the previous work by mechanically examining the effects of THF on dioxane degradation in a microbial community context.