Chapter 1 - Metagenomics: A Paradigm Shift in Microbiology

Abstract

Uncultured microorganisms are the ones mostly responsible for natural biodiversity on Earth. Typically, more than 99% of microorganisms from natural ecosystems cannot be cultured under laboratory conditions. Therefore, there is a demand for culture-independent approaches for identification and characterization of such microorganisms and uncovering their ecological roles in the biosphere. Metagenomics is culture-independent, sequencing-based and/or function-based analysis of the collective genome of a microbial community, which enables collection of essential information about community structure and genetic and metabolic potential of the members, thus providing insights into the biology of these microorganisms. Another culture-independent method is single-cell genomics, which obtains information about microbial population based on the isolation and genome sequencing of a single cell. This chapter presents an overview of the history of metagenomics and describes the main approaches used for analysis of microbial communities, including the synergy between metagenomics and single-cell genomics, and outlines further directions in this field.