Polyhydroxyalkanoates (PHAs), the intracellular polymers produced by various microorganisms as carbon and energy storage, are of great technological potential as biodegradable versions of common plastics. PHA-producing microbes are therefore in great demand and a plethora of different environments, especially extreme habitats, have been probed for the presence of PHA-accumulators. However, the polar region has been neglected in this regard, probably due to the low accessibility of the sampling material and unusual cultivation regime. Here, we present the results of a screening procedure involving 200 bacterial strains isolated from 25 habitats of both polar regions. Agar-based tests, microscopy, and genetic methods were conducted to elucidate the biodiversity and potential of polar-region PHA-accumulators. Microscopic observation of Nile Red stained cells proved to be the most reliable screening method as it allowed to confirm the characteristic bright orange glow of the Nile Red–PHA complex as well as the typical morphology of the PHA inclusions. Psychrophilic PHA-producers belonged mostly to the Comamonadaceae family (Betaproteobacteria) although actinobacterial PHA synthesizers of the families, Microbacteriaceae and Micrococcaceae also featured prominently. Glacial and postglacial habitats as well as developed polar region soils, were evaluated as promising for PHA-producer bioprospection. This study highlights the importance of psychrophiles as biodiverse and potent polyhydroxyalkanoate sources for scientific and application-aimed research.

中文翻译：

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极地产聚羟基链烷酸细菌的生物多样性和栖息地：通过流行的筛选方法进行生物勘探

聚羟基链烷酸酯 (PHA) 是由各种微生物产生的细胞内聚合物，作为碳和能量储存器，作为普通塑料的可生物降解版本具有巨大的技术潜力。因此，对产生 PHA 的微生物有很大的需求，并且已经在大量不同的环境，尤其是极端栖息地中探索了 PHA 蓄积器的存在。然而，极地地区在这方面被忽视了，可能是由于采样材料的可及性低和不寻常的栽培制度。在这里，我们展示了筛选程序的结果，该程序涉及从两个极地地区的 25 个栖息地中分离出的 200 种细菌菌株。进行了基于琼脂的测试、显微镜检查和遗传方法，以阐明极地地区 PHA 蓄积器的生物多样性和潜力。尼罗红染色细胞的显微镜观察证明是最可靠的筛选方法，因为它可以确认尼罗红-PHA 复合物的特征性亮橙色发光以及 PHA 包裹体的典型形态。嗜冷 PHA 生产者主要属于 Comamonadaceae 科（Betaproteobacteria），尽管该科、微杆菌科和微球菌科的放线菌 PHA 合成器也具有显着特征。冰川和冰川后栖息地以及发达的极地地区土壤被评估为有希望用于 PHA 生产者生物勘探。这项研究强调了嗜冷菌作为生物多样性和有效的聚羟基链烷酸酯来源对科学和应用研究的重要性。