Editorial: Microbial Life Under Stress: Biochemical, Genomic, Transcriptomic, Proteomic, Bioinformatics, Evolutionary Aspects, and Biotechnological Applications of Poly-Extremophilic Bacteria, Volume II

Habitats defined as “extremes” exist across the entire planet. They can be widely different in their physico-chemical features as they include a diverse array of harsh parameters thought to preclude the existence of living organisms, such as temperature, pH, salinity, radiation, pressure, low water activity, low nutrients, and even the presence of toxic agents such as metals and/or metalloids. Organisms capable of surviving or thriving in those habitats are named “extremophiles” and the vast majority of them are prokaryotes, which is not surprising as they show a remarkable reservoir of genomes allowing them to grow in a great variety of hostile niches. Interestingly, several harsh conditions may occur simultaneously and the microorganisms able to withstand them are called “poly-extremophiles”. Although many bacterial species from all kinds of extreme environments have been isolated and described in the last decades, very little is known about the molecular strategies and physiology that allow them to grow in such critical conditions. The aim of this Research Topic on Microbial Life Under Stress (Volume II) is to address this issue by applying multidisciplinary approaches for integrating data from biochemical, genomic, transcriptomic, proteomic, bioinformatics, and evolutionary studies of bacteria from extreme and poly-extreme environments. This Research Topic consists of 14 original articles by numerous authors actively engaged in the study of microbiology, biochemistry, and omic-research of extremophiles. The present Editorial can be divided into four sections which include groups of articles on different genera and species of acidophiles, studies on microorganisms from arid/desiccated environments but also from habitats at low and high temperatures, and finally, a set of papers on extremophiles capable of coping with extreme levels of radiation, pressure, and toxic metals.