ABSTRACT
Abstract To date, anaerobic (methanogenic) fermentation technology has been widely applied to the treatment of municipal and industrial wastes and wastewaters. A number of anaerobic processes have been intensively developed, and the application of these processes is being expanded to low-strength wastewaters, wastes and wastewaters under extreme temperature conditions, and more complex wastewaters containing anthropogenic compounds and/or compounds that are recalcitrant to biodegradation. The recent development of molecular techniques in the field of microbial ecology has allowed us to explore the microbial diversity and community structure of those anaerobic processes. As a result of the development and application of these techniques, we now have better insight into the community composition and architecture of anaerobic sludge, which can be adapted to treat a variety of waste/wastewaters under different operation conditions. Importantly, the community was found to be composed in large part of various yetto-be cultured microorganisms, some of which were often found to play significant roles in those anaerobic processes. To reveal the function of the community constituents, numerous efforts have been made to isolate relevant microbes in the anaerobic processes, and the information on the functions of the microbes in anaerobic sludge is accumulating at an encouraging rate. In this chapter, the state-of-the-art anaerobic waste/wastewater treatment technologies, the microbial community structure in anaerobic sludge, and the functions of individual populations are summarized.
