Institute of Microbiology of the CAS, v. v. i., Prague, Czech Republic.
Biotechnol Adv. 2021 Dec;53:107698. doi: 10.1016/j.biotechadv.2021.107698. Epub 2021 Jan 28.
Rhodococci are bacteria which can survive under various extreme conditions, in the presence of toxic compounds, and in other hostile habitats. Their tolerance of unfavorable conditions is associated with the structure of their cell wall and their large array of enzymes, which degrade or detoxify harmful compounds. Their physiological and biotechnological properties, together with tools for their genetic manipulation, enable us to apply them in biotransformations, biodegradation and bioremediation. Many such biotechnological applications cause stresses that positively or negatively affect their efficiency. Whereas numerous reviews on rhodococci described their enzyme activities, the optimization of degradation or production processes, and corresponding technological solutions, only a few reviews discussed some specific effects of stresses on the physiology of rhodococci and biotechnological processes. This review aims to comprehensively describe individual stress responses in Rhodococcus strains, the interconnection of different types of stresses and their consequences for cell physiology. We examine here the responses to (1) environmental stresses (desiccation, heat, cold, osmotic and pH stress), (2) the presence of stress-inducing compounds (metals, organic compounds and antibiotics) in the environment (3) starvation and (4) stresses encountered during biotechnological applications. Adaptations of the cell envelope, the formation of multicellular structures and stresses induced by the interactions of hosts with pathogenic rhodococci are also included. The roles of sigma factors of RNA polymerase in the global regulation of stress responses in rhodococci are described as well. Although the review covers a large number of stressful conditions, our intention was to provide an overview of the selected stress responses and their possible connection to biotechnological processes, not an exhaustive survey of the scientific literature. The findings on stress responses summarized in this review and the demonstration of gaps in current knowledge may motivate researchers working to fill these gaps.
罗德里氏菌是一种能够在各种极端条件下生存的细菌，能够耐受有毒化合物，并在其他恶劣的生境中生存。它们对不利条件的耐受性与其细胞壁的结构及其大量的酶有关，这些酶可以降解或解毒有害化合物。它们的生理和生物技术特性，以及遗传操作工具，使我们能够将其应用于生物转化、生物降解和生物修复。许多这样的生物技术应用会产生压力，这些压力会对它们的效率产生积极或消极的影响。虽然有许多关于罗德里氏菌的综述描述了它们的酶活性、降解或生产过程的优化以及相应的技术解决方案，但只有少数综述讨论了一些特定的压力对罗德里氏菌生理学和生物技术过程的影响。本综述旨在全面描述罗德里氏菌菌株的个体应激反应、不同类型的应激之间的相互联系及其对细胞生理学的后果。我们在这里研究了对以下方面的反应：（1）环境压力（干燥、热、冷、渗透压和 pH 应激）；（2）环境中存在的应激诱导化合物（金属、有机化合物和抗生素）；（3）饥饿；（4）在生物技术应用中遇到的压力。细胞包膜的适应、多细胞结构的形成以及宿主与致病性罗德里氏菌相互作用引起的压力也包括在内。还描述了 RNA 聚合酶的 sigma 因子在罗德里氏菌全局调节应激反应中的作用。虽然该综述涵盖了大量的应激条件，但我们的目的是提供对所选应激反应及其与生物技术过程可能的联系的概述，而不是对科学文献的详尽调查。本综述中总结的应激反应的发现以及对当前知识空白的论证，可能会激励致力于填补这些空白的研究人员。
