Enzymatic Degradation of Phenazines Can Generate Energy and Protect Sensitive Organisms from Toxicity.
Enzymatic Degradation of Phenazines Can Generate Energy and Protect Sensitive Organisms from Toxicity.
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DOI：
10.1128/mbio.01520-15
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发表时间：
2015-10-27
期刊：
影响因子：
6.4
通讯作者：
Newman DK
中科院分区：
文献类型：
--
作者：
Costa KC;Bergkessel M;Saunders S;Korlach J;Newman DK
多种细菌，包括几种假单胞菌，产生一类称为吩嗪的氧化还原活性代谢物，影响自然界和疾病中的不同细胞类型。吩嗪可以以积极和消极的方式影响微生物群落，它们的存在与物种丰富度和多样性的减少有关。然而，很少有人知道吩嗪的浓度是如何在原位调制，这可能意味着什么的健身社区的成员。通过培养吩嗪降解分枝杆菌，基因组测序，比较基因组学和分子分析，我们确定了几个保守的基因，是重要的降解三个假单胞菌衍生的吩嗪：吩嗪-1-羧酸（PCA），吩嗪-1-甲酰胺（PCN），绿脓菌素（PYO）。五氯苯甲醚可用作这些生物生长的唯一碳源。偶然分枝杆菌中几个基因的缺失消除了降解表型，并且在异源宿主中两个基因的表达赋予了降解PCN和PYO的能力。在与吩嗪生产者的共培养中，吩嗪降解剂改变了不同吩嗪类型的丰度。降解不仅支持分枝杆菌催化剂，而且还为否则将被PYO毒性抑制的细菌提供保护。总的来说，这些结果提醒人们，微生物代谢物可以被积极地修饰和降解，当评估这些化合物在任何环境中的命运和影响时，必须考虑这些周转过程。假单胞菌属生产吩嗪的研究可以在从囊性纤维化肺到旱地作物根际的各种环境中形成微生物群落。例如，在根际，吩嗪可以保护植物免受病原真菌的感染。吩嗪的氧化还原活性支持它们的抗生素活性，以及为假单胞菌提供重要的生理益处。我们的发现，土壤分枝杆菌可以分解代谢吩嗪，从而保护其他生物体对吩嗪毒性表明，吩嗪降解可能会影响营业额在原位。参与吩嗪降解的基因的鉴定打开了在不同环境中监测营业额的大门，当人们试图了解或控制受吩嗪影响的社区时，这是一个必须考虑的过程。
Diverse bacteria, including several Pseudomonas species, produce a class of redox-active metabolites called phenazines that impact different cell types in nature and disease. Phenazines can affect microbial communities in both positive and negative ways, where their presence is correlated with decreased species richness and diversity. However, little is known about how the concentration of phenazines is modulated in situ and what this may mean for the fitness of members of the community. Through culturing of phenazine-degrading mycobacteria, genome sequencing, comparative genomics, and molecular analysis, we identified several conserved genes that are important for the degradation of three Pseudomonas-derived phenazines: phenazine-1-carboxylic acid (PCA), phenazine-1-carboxamide (PCN), and pyocyanin (PYO). PCA can be used as the sole carbon source for growth by these organisms. Deletion of several genes in Mycobacterium fortuitum abolishes the degradation phenotype, and expression of two genes in a heterologous host confers the ability to degrade PCN and PYO. In cocultures with phenazine producers, phenazine degraders alter the abundance of different phenazine types. Not only does degradation support mycobacterial catabolism, but also it provides protection to bacteria that would otherwise be inhibited by the toxicity of PYO. Collectively, these results serve as a reminder that microbial metabolites can be actively modified and degraded and that these turnover processes must be considered when the fate and impact of such compounds in any environment are being assessed. Phenazine production by Pseudomonas spp. can shape microbial communities in a variety of environments ranging from the cystic fibrosis lung to the rhizosphere of dryland crops. For example, in the rhizosphere, phenazines can protect plants from infection by pathogenic fungi. The redox activity of phenazines underpins their antibiotic activity, as well as providing pseudomonads with important physiological benefits. Our discovery that soil mycobacteria can catabolize phenazines and thereby protect other organisms against phenazine toxicity suggests that phenazine degradation may influence turnover in situ. The identification of genes involved in the degradation of phenazines opens the door to monitoring turnover in diverse environments, an essential process to consider when one is attempting to understand or control communities influenced by phenazines.