Understanding the Structure and Function of Extreme Microbiome Through Genomics

Extremophilic microorganisms thrive in harsh conditions of environment. Understanding the nature of such microorganisms and their metabolic functions remain a subject of immense scientific interest. Although during past several decades microbiologists were able to catalogue many of the extreme microbiomes, recent high-throughput sequencing-based cultivation independent approaches have enabled us to gain a better insight in to their details. In this chapter, microbiomes of two extreme environments: acid-mine drainage and geothermally heated subsurface reservoir are presented. Microbial diversity of the extreme environments across sites across the world is discussed with emphasis of enrichment and isolation, followed by 16S rRNA-based study, clone library, amplicon, and finally whole-metagenome sequencing (described with respect to genomics). Metabolic potential of microbes and biogeochemical cycles in these sites is reviewed. Potential applications either fundamental research question like the origins of life or biotechnological aspect like bioprospecting, bioremediation, etc. were highlighted. Finally, challenges in analyzing genomics data for studying extreme environment microbiology are indicated.