Applications of Metagenomics in Microbial Diversity and Function Analysis: Recent Trends and Advances

Abstract

Every year, two billion tonnes of waste is generated globally, most of which is kept in landfills and then disposed into oceans. This is a potential threat to the environment as it contaminates the land. Due to industrial wastewater, the atmosphere is also contaminated. Many microorganisms can be found in polluted areas. A municipal dump is an example of a man-made ecosystem that supports a diverse community of microorganisms. Microorganisms can degrade waste by secreting enzymes. Because of their excellent specificity and cost-effectiveness, enzymes or microbial cells are used as biological catalysts. Organic and inorganic wastes are degraded and detoxified by microorganisms. In the biomethanation process, methane gas is produced, which is used as a biofuel, and compost is produced from the composting process, which is used in agricultural processing; many microorganisms living in waste are useful in these processes. Metagenomics is an advanced molecular technique to identify the microbial diversity present in different types of wastes and is used for environmental cleanup. Metagenomics describes the genomic analysis of microbial DNA extracted directly from a sample, and it is a high-throughput gene-level study of mixed microbial communities. During bioremediation in a contaminated environment, metagenomic approaches are currently being used to better understand the makeup and study of microbial communities. The major enzymes and genes involved in the breakdown and detoxification of environmental contaminants can be accurately identified using the next-generation sequencing (NGS) technology. The purpose of this chapter is to provide a fundamental understanding of the metagenomic methodology and applications in order to better understand microbial diversity, functions, and structures in contaminated environments.