22 - Molecular biological techniques used in environmental engineering: current prospects and challenges

Abstract

Wastewater treatment has gained increased importance worldwide due to the increasing demand for clean water. Biological treatment achieved by the activities of the microbial community is one of the most widely used processes in the treatment of wastewater. Consequently, wastewater treatment facilities have been created to maintain high densities and activities of those microorganisms that satisfy the various purification demands. The diversity and interaction of microbes present in the complex environment of wastewater treatment reactors are studied using molecular techniques. In this chapter, we discussed the current and emerging molecular approaches for characterizing microbial community composition and structure in wastewater processes. Both denaturing gradient gel electrophoresis (DGGE) and fluorescence in situ hybridization (FISH) have been extensively employed methods. The formation, quantification, and distribution of different microbial groups in granules and biofilms, as well as their structure and architecture, are demonstrated by FISH technique. For identifying the microorganisms, polymerase chain reaction-based methods (cloning and DGGE) are used that form the sludge in the reactor.