Ecological implications of hypoxia-triggered shifts in secondary metabolism.
Ecological implications of hypoxia-triggered shifts in secondary metabolism.
复制标题
缺氧引发的次生代谢变化的生态学意义。
DOI：
10.1111/1462-2920.13700
复制
发表时间：
2017
影响因子：
5.1
通讯作者：
Jensen,PaulR
中科院分区：
文献类型：
--
作者：
Gallagher,KelleyA;Wanger,Greg;Henderson,Jane;Llorente,Mark;Hughes,ChambersC;Jensen,PaulR
放线菌属链霉菌属是一种非运动性丝状细菌，以产生生物医学上相关的次生代谢物而闻名。虽然被认为是专性需氧细菌，但人们对这些细菌如何应对其自然栖息地(包括土壤和海洋沉积物)中氧气供应减少的时期知之甚少。在这里，我们提供了海洋链霉菌菌株CNQ-525能够通过扩散机制还原MnO2的证据。我们研究了低氧对次生代谢物产生的影响，并观察到从抗生素奈比拉霉素转向8-氨基-小黄素，这是奈比拉霉素生物合成途径的中间体。我们纯化了8-氨基小黄素，并证明它具有可逆氧化还原活性(中点电位−为474.5 mV)，表明它具有作为内源性细胞外电子穿梭的潜力。这项研究提供的证据表明，环境引发的次生代谢物产生的变化可能为特定化合物的生态功能提供线索，并且被认为是专性需氧菌的革兰氏阳性菌可能通过包括细胞外电子穿梭在内的机制在生物地球化学循环中发挥以前不为人知的作用。
Members of the actinomycete genusStreptomycesare non‐motile, filamentous bacteria that are well‐known for the production of biomedically relevant secondary metabolites. While considered obligate aerobes, little is known about how these bacteria respond to periods of reduced oxygen availability in their natural habitats, which include soils and ocean sediments. Here, we provide evidence that the marine streptomycete strain CNQ‐525 can reduce MnO2via a diffusible mechanism. We investigated the effects of hypoxia on secondary metabolite production and observed a shift away from the antibiotic napyradiomycin towards 8‐amino‐flaviolin, an intermediate in the napyradiomycin biosynthetic pathway. We purified 8‐amino‐flaviolin and demonstrated that it is reversibly redox‐active (midpoint potential −474.5 mV), indicating that it has the potential to function as an endogenous extracellular electron shuttle. This study provides evidence that environmentally triggered changes in secondary metabolite production may provide clues to the ecological functions of specific compounds, and that Gram‐positive bacteria considered to be obligate aerobes may play previously unrecognized roles in biogeochemical cycling through mechanisms that include extracellular electron shuttling.