Microbe-microbe interactions trigger Mn(II)-oxidizing gene expression
Microbe-microbe interactions trigger Mn(II)-oxidizing gene expression
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微生物与微生物的相互作用触发锰（II）氧化基因表达
DOI：
10.1038/ismej.2016.106
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发表时间：
2017-01-01
期刊：
影响因子：
11
通讯作者：
Qu, Jiuhui
中科院分区：
文献类型：
--
作者：
Liang, Jinsong;Bai, Yaohui;Qu, Jiuhui
锰是地球化学循环中的重要金属元素。一些微生物可以将Mn（II）氧化成Mn氧化物，这反过来又可以通过强吸附和氧化效应影响其他元素的全球循环。微生物-微生物相互作用在许多生物过程中具有重要作用。然而，微生物的相互作用如何影响Mn（II）的氧化仍然是未知的。在这里，我们研究了两种细菌（节杆菌属和鞘氨醇菌属）之间的相互作用。在共培养物中，其表现出Mn（II）氧化活性，尽管两者都不能单独氧化Mn（II）。我们证明，Mn（II）氧化活性在共培养最有可能通过接触依赖性的相互作用诱导。在共培养物中表达的Mn（II）-氧化蛋白被纯化并鉴定为属于节杆菌属菌株的胆红素氧化酶。对胆红素氧化酶编码基因（boxA）进行全测序。Mn（II）-氧化蛋白和boxA的成绩单中检测到的共培养，但不是在任何一个隔离的文化。这表明boxA在节杆菌单一培养物中是沉默的，并且响应于在共培养物中鞘氨醇的存在而被激活。此外，通过RNA-Seq的转录组学分析、细胞外超氧化物检测和通过流式细胞术的细胞密度定量表明节杆菌中boxA基因表达的诱导与通过与鞘氨醇菌共培养触发的应激反应是一致的。我们的研究结果表明，在Mn（II）氧化和胞外超氧化物的产生由其他微生物诱导的压力的微生物生理反应的潜在作用。
Manganese (Mn) is an important metal in geochemical cycles. Some microorganisms can oxidize Mn (II) to Mn oxides, which can, in turn, affect the global cycles of other elements by strong sorption and oxidation effects. Microbe-microbe interactions have important roles in a number of biological processes. However, how microbial interactions affect Mn(II) oxidation still remains unknown. Here, we investigated the interactions between two bacteria (Arthrobacter sp. and Sphingopyxis sp.) in a co-culture, which exhibited Mn(II)-oxidizing activity, although neither were able to oxidize Mn(II) in isolation. We demonstrated that the Mn(II)-oxidizing activity in co-culture was most likely induced via contact-dependent interactions. The expressed Mn(II)-oxidizing protein in the co-culture was purified and identified as a bilirubin oxidase belonging to strain Arthrobacter. Full sequencing of the bilirubin oxidase-encoding gene (boxA) was performed. The Mn(II)-oxidizing protein and the transcripts of boxA were detected in the co-culture, but not in either of the isolated cultures. This indicate that boxA was silent in Arthrobacter monoculture, and was activated in response to presence of Sphingopyxis in the co-culture. Further, transcriptomic analysis by RNA-Seq, extracellular superoxide detection and cell density quantification by flow cytometry indicate induction of boxA gene expression in Arthrobacter was co-incident with a stress response triggered by co-cultivation with Sphingopyxis. Our findings suggest the potential roles of microbial physiological responses to stress induced by other microbes in Mn(II) oxidation and extracellular superoxide production.