González Toril, E., Aguilera, A. 2019. Microbial Ecology in Extreme Acidic Environments: Use of Molecular Tools. Microbial Diversity in the Genomic Area, 227-238 DOI: 10.1016/B978-0-12-814849-5.00014-9
A major issue in microbial ecology is to identify the limits of life for growth and survival and to understand the molecular mechanisms that define these limits. Thus, interest in the biodiversity and ecology of extreme environments has grown in recent years for several reasons. Some are basic and revolve around the idea that extreme environments are believed to reflect early Earth conditions. Other issues are related to the biotechnological potential of extremophiles, such as the use of the metabolic properties of some microorganisms for metal extraction. In this regard, the study of extremely acidic environments (pH<3) has become increasingly important since environmental acidity is often caused by microbial activity. The advent of high-throughput sequencing technologies has allowed sampling microbial diversity more deeply and widely than ever before and thus affords new opportunities for comprehensively examining broader trends of microbial distribution with larger numbers of ecological samples. Acidic extreme environments are unique ecological niche for acid- and toxic-metal-adapted microorganisms. These low-complexity systems offer a special opportunity for the ecological and evolutionary analyses of natural microbial assemblages. The last decade has witnessed an unprecedented interest in the study of acidophilic communities using 16S rRNA high-throughput sequencing and community genomic and postgenomic methodologies, significantly advancing our understanding of microbial diversity, community function, and evolution in acidic environments. This chapter summarizes the current status of our knowledge of extreme acidic environments microbial ecology through the use of meta-“omic” molecular techniques.