1.1.1 Different Conditions of the Reactor

There are many types of fed-batch composting (FBC) reactors. However, FBC reac­tors cannot function continuously because the contents, which usually include waste and biomass-carriers such as wood chips, often aggregate after prolonged opera­tion. Therefore, it is necessary to remove excess contents from the reactor regularly because of decreasing decomposition rate, and this requires secondary treatment of the aggregated contents. Since considerable amounts of partially degraded materials remain during the FBC process, secondary treatment of the products is necessary to obtain matured compost or complete degradation of waste to organic mat­ter. Although the mechanism of aggregation in reactors is unknown, this process decreases the decomposition rate [14], and probably changes the microbial commu­nity. Therefore, this study was conducted to compare the optimal and aggregated conditions of a bacterial community in a FBC reactor using 16S rDNA clone analysis.