Inorganic polyphosphate (polyP) is a linear polymer consisting of dozens to hundreds of orthophosphate residues (Pi) linked by high-energy phosphoanhydride bond.The studies have demonstrated that polyP is accumulated in bacteria under the unsuitable life conditions and endows bacteria with strong tolerance against environmental stresses,which trigger the stringent response along with the related enzymes of PPK,PPX and pppGpp.In oligotrophic environment,polyP acts as energy and Pi reservoir.More importantly,it participates in a series of starvation stress response together with RpoS,protease Lon,σ factor,etc.Such survival mechanism is similar to the life style of oligotrophic bacteria.All of these benefits from the flexibility and electron-density of polyP polymer,but its specific regulation mechanisms are still unclear.This review states the DAPI-based method to observe (fluorescent or electron microscope) and determine (fluorospectrophotometer) polyP in bacterial bodies,and mainly summarizes and analyzes the “core polyP” mechanistic alternatives in tuning microbial fitness for the adaptation under harsh living conditions.%多聚磷酸盐(polyP)是由几个到上百个磷酸基团组成并由高能磷酸酐键连接的链状无机化合物,广泛地存在于所有生命体中.研究表明,polyP在不适宜的生存条件下会在菌体内聚集,使菌对环境压力有极强的耐受性,它与其相关的酶PPK、PPX、pppGpp等一起作出应激反应;在寡营养环境下,polyP作为能量和磷源库,和RpoS、Lon蛋白及σ因子等一起参与一系列饥饿压力应答,这种存活机制与寡营养菌的生活方式类似.这些反应得益于polyP链状的灵活性和高荷电性,但是其具体的调控机理仍很少为人所知.本文阐述了以4',6-二脒基-2-苯基吲哚(4’,6-Diamidino-2-phenylindole,DAPI)为基础的荧光染色方法进行菌体内polyP的定性(荧光或电子显微镜)和定量(荧光分光光度计),重点归纳分析了以polyP为核心的关于细菌适应恶劣生存环境的代替机制.
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