Chemotaxis of Pseudomonas putida F1 to Alcohols Is Mediated by the Carboxylic Acid Receptor McfP
Chemotaxis of Pseudomonas putida F1 to Alcohols Is Mediated by the Carboxylic Acid Receptor McfP
复制标题
DOI：
10.1128/aem.01625-19
复制
发表时间：
2019-08
影响因子：
4.4
通讯作者：
Xiangsheng Zhang;J. Hughes;Gabriel A. Subuyuj;J. Ditty;R. Parales
中科院分区：
文献类型：
--
作者：
Xiangsheng Zhang;J. Hughes;Gabriel A. Subuyuj;J. Ditty;R. Parales
醇类作为发酵产物释放，并作为许多有机化合物（包括烃和脂肪酸）催化剂的中间产物产生，是土壤和沉积物中微生物食物网的常见组成部分。虽然它们是许多土壤细菌的良好碳源和能源，但据报道，醇主要是运动细菌的驱避剂而不是引诱剂。人们对环境中的微生物如何感知酒精知之甚少。我们在这里报告，可分解的n-醇与线性链的高达12个碳作为土壤细菌恶臭假单胞菌的引诱剂，而不是被直接检测到，醇似乎被分解代谢为乙酸，然后感测到的特定的细胞表面化学感受器蛋白。摘要虽然醇类对许多微生物都有毒性，但对一些细菌，包括许多假单胞菌来说，它们是很好的碳源和能源。然而，大多数研究已经检查了对酒精的化学感觉反应，报告说酒精被感觉为驱避剂，这与它们的毒性特性一致。在这项研究中，我们研究了恶臭假单胞菌菌株F1的趋化性与1至12个碳链长度的正醇。恶臭假单胞菌F1被作为该菌株生长底物（C2至C12）的所有正-醇所吸引，并且当细胞在醇存在下生长时诱导反应。通过测定缺乏单个或多个甲基接受趋化性蛋白的突变菌株，介导对C2至C12醇的响应的受体被鉴定为McfP，其为恶臭假单胞菌菌株KT 2440的C2和C3羧酸受体的直系同源物。除了作为对正醇的响应的需要，McfP是恶臭假单胞菌F1对丙酮酸、l-乳酸、乙酸和丙酸的响应所必需的，这些响应由KT 2440受体检测，以及中链和长链羧酸己酸和十二烷酸。携带mcfP-lacZ转录融合体的恶臭假单胞菌F1的β-半乳糖苷酶测定显示，mcfP基因不响应于醇而被诱导。总之，我们的结果是一致的想法，从醇的氧化产生的羧酸是实际的引诱剂在恶臭假单胞菌F1中的McfP感测，而不是醇本身。重要性醇类作为发酵产物释放，并作为许多有机化合物（包括碳氢化合物和脂肪酸）催化过程中的中间产物产生，是土壤和沉积物中微生物食物网的常见组成部分。虽然它们是许多土壤细菌的良好碳源和能源，但据报道，醇主要是运动细菌的驱避剂而不是引诱剂。人们对环境中的微生物如何感知酒精知之甚少。我们在这里报告，可分解的n-醇与线性链的高达12个碳作为土壤细菌恶臭假单胞菌的引诱剂，而不是被直接检测到，醇似乎被分解代谢为乙酸，然后感测到的特定的细胞表面化学感受器蛋白。
Alcohols, released as fermentation products and produced as intermediates in the catabolism of many organic compounds, including hydrocarbons and fatty acids, are common components of the microbial food web in soil and sediments. Although they serve as good carbon and energy sources for many soil bacteria, alcohols have primarily been reported to be repellents rather than attractants for motile bacteria. Little is known about how alcohols are sensed by microbes in the environment. We report here that catabolizable n-alcohols with linear chains of up to 12 carbons serve as attractants for the soil bacterium Pseudomonas putida, and rather than being detected directly, alcohols appear to be catabolized to acetate, which is then sensed by a specific cell-surface chemoreceptor protein. ABSTRACT Although alcohols are toxic to many microorganisms, they are good carbon and energy sources for some bacteria, including many pseudomonads. However, most studies that have examined chemosensory responses to alcohols have reported that alcohols are sensed as repellents, which is consistent with their toxic properties. In this study, we examined the chemotaxis of Pseudomonas putida strain F1 to n-alcohols with chain lengths of 1 to 12 carbons. P. putida F1 was attracted to all n-alcohols that served as growth substrates (C2 to C12) for the strain, and the responses were induced when cells were grown in the presence of alcohols. By assaying mutant strains lacking single or multiple methyl-accepting chemotaxis proteins, the receptor mediating the response to C2 to C12 alcohols was identified as McfP, the ortholog of the P. putida strain KT2440 receptor for C2 and C3 carboxylic acids. Besides being a requirement for the response to n-alcohols, McfP was required for the response of P. putida F1 to pyruvate, l-lactate, acetate, and propionate, which are detected by the KT2440 receptor, and the medium- and long-chain carboxylic acids hexanoic acid and dodecanoic acid. β-Galactosidase assays of P. putida F1 carrying an mcfP-lacZ transcriptional fusion showed that the mcfP gene is not induced in response to alcohols. Together, our results are consistent with the idea that the carboxylic acids generated from the oxidation of alcohols are the actual attractants sensed by McfP in P. putida F1, rather than the alcohols themselves. IMPORTANCE Alcohols, released as fermentation products and produced as intermediates in the catabolism of many organic compounds, including hydrocarbons and fatty acids, are common components of the microbial food web in soil and sediments. Although they serve as good carbon and energy sources for many soil bacteria, alcohols have primarily been reported to be repellents rather than attractants for motile bacteria. Little is known about how alcohols are sensed by microbes in the environment. We report here that catabolizable n-alcohols with linear chains of up to 12 carbons serve as attractants for the soil bacterium Pseudomonas putida, and rather than being detected directly, alcohols appear to be catabolized to acetate, which is then sensed by a specific cell-surface chemoreceptor protein.