Microbiology of Fed-batch Composting

Abstract

Repeated fed-batch composting (FBC) processes, which are modifications of traditional composting technology, have in recent years attracted attention not only in their biotechnological aspects but also from ecological viewpoints. FBC processes differ from the conventional batch system in that the biodegradation of solid organic waste proceeds without definitive thermal stages including the thermophilic phase under self-heating conditions. Mesophilic FBC processes for treating household biowaste are also characterized by low moisture contents, alkaline pH and the presence of high population densities of microorganisms under steady state conditions. Kinetic and microbiological studies of the FBC process have increasingly been conducted using commercially available composters as well as laboratory-and bench-scale reactors. Information from recent studies on FBC processes has provided new insight into our understanding of compost microbiology. This article reviews current knowledge of the FBC process with a special emphasis on microbial diversity, succession and activity in garbage composters. The potential application of FBC technology for bioremediation purpose is also discussed.