Microbial community genetics, transcriptomics, proteomics, and metabolomics

Major contaminants wastewaters are organic compounds, xenobiotics, metals, suspended soils, nutrients (mainly nitrogen and phosphorus), and pathogenic microorganisms. Biological wastewater treatment systems have been used to remove domestic and industrial wastes from water. Wastewater treatment plants (WWTPs) are considered as a barrier and dissemination point of antibiotic-resistant bacteria. Denitrification, ammonification, nitrogen fixation, and nitrification are key parameters of nitrogen cycle in wastewater treatment. Highly complex and diverse microbial communities are predominant in wastewater treatment systems. These microbial communities affect each other in stressful environmental conditions. To understand better interactions between these complex microbial communities, omics approaches such as genomics, transcriptomics, proteomics, and metabolomics are need to apply in WWTPs. The generation of large next-generation sequencing data will provide taxonomic and functional diversity of environmental microbial communities. Metatranscriptomics and metaproteomics approaches identify the functional dynamics of microbial communities in environmental processes. This chapter represents the signatures of microbial communities that are involved in the dissemination of antibiotic resistance genes and nutrient-removing in WWTPs by using metagenomic, metatranscriptomic, and metaproteomic approaches.