Effect of riboflavin on active bacterial communities and arsenic-respiring gene and bacteria in arsenic-contaminated paddy soil
Effect of riboflavin on active bacterial communities and arsenic-respiring gene and bacteria in arsenic-contaminated paddy soil
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DOI：
10.1016/j.geoderma.2020.114706
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发表时间：
2021-01
期刊：
影响因子：
6.1
通讯作者：
J. Qiao;Xiaomin Li;Fangbai Li;Songxiong Zhong;Manjia Chen
中科院分区：
文献类型：
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作者：
J. Qiao;Xiaomin Li;Fangbai Li;Songxiong Zhong;Manjia Chen
核黄素是一种广泛分布的微量营养素，由许多细菌分泌，可作为氧化还原介质，促进细胞外电子转移。然而，RF对砷污染稻田中活性菌群动态迁移和砷酸盐[As(V)]呼吸基因及相关细菌转录的影响研究尚不多见。在砷污染的水稻土中，用RF和乳酸盐进行了厌氧微生物的培养。砷和铁的转化表明，微生物As(V)和Fe（III）的还原主要发生在孵育的前12天，这两个过程同时发生，RF大大增强了这两个过程。活性细菌群落动态（基于16S rRNA基因）显示，RF主要增加了geobacter、Clostridium、pelobacteraceaeon 0 ~ 12天的相对丰度，以及decchloromonas12 ~ 40天的相对丰度，而对细菌多样性没有影响。构建了arragene转录本克隆文库，分析了RF刺激下As(V)-呼吸细菌的动态迁移，结果表明As(V)-呼吸器geobacterspp。在孵育期间以RF和乳酸微环境为主。定量逆转录- pcr （RT-qPCR）分析显示，arragene和geobacterspp .的转录水平均低于对照组。在前5天显著增加，相对于单独添加乳酸盐的微环境，RF显著增强。共现网络分析表明，arragene /Geobacterspp转录物丰度与基因序列呈正相关。并在RF和乳酸存在下溶解As(V)。我们的研究结果表明，射频刺激本地优势金属还原细菌的活性；在砷污染的水稻土中，增加As(V)呼吸基因和细菌的转录，促进砷的还原和释放。
Riboflavin (RF) is a widely distributed micronutrient secreted by many bacteria and can serve as a redox mediator to facilitate extracellular electron transfer. However, studies on the effect of RF on the dynamic shift of active bacterial communities and transcription of arsenate [As(V)]-respiring genes and associated bacteria in arsenic-contaminated paddy fields remain rare. In this study, anaerobic microcosms were established with arsenic-contaminated paddy soil amended with RF and lactate. Arsenic and iron transformation showed that microbial As(V) and Fe(III) reduction took place principally within the first 12 days of incubation, when both occurred simultaneously and were substantially enhanced by RF. Dynamics of the active bacterial community (16S rRNA gene based) revealed that RF mainly increased the relative abundance ofGeobacter,Clostridium, andPelobacteraceaeon days 0–12 and that ofDechloromonason days 12–40, whereas RF had no influence on bacterial diversity. A transcript clone library ofarrAgene was constructed to profile the dynamic shift of As(V)-respiring bacteria stimulated by RF, which indicated that As(V)-respiringGeobacterspp. dominated in the RF and lactate microcosms during the incubation period. Quantitative reverse transcription-PCR (RT-qPCR) analyses revealed that the transcription ofarrAgene andGeobacterspp. predominantly increased during the first 5 days and was substantially enhanced by RF relative to microcosms with lactate alone. Co-occurrence network analysis indicated a positive correlation between the transcript abundance ofarrAgene/Geobacterspp. and dissolved As(V) in the presence of RF and lactate. Our results demonstrate that RF stimulates the activity of indigenous dominant metal-reducing bacteria; moreover, it increases transcription of the As(V)-respiring gene and bacteria to facilitate arsenic reduction and release in arsenic-contaminated paddy soil.