Hidehiro Kaneko*, Young Jin Bae** and Kenji Fujita***

*Faculty of Engineering, Yamanashi University
(4-3-11, Takeda, Kofu, Yamanashi 400, Japan)
**Korea Institute of Construction Technology
***Faculty of Engineering, The University of Tokyo

Abstract

Change in microbial numbers during experimental composting has been investigated. The results show that bacteria and actinomycetes play an important role in decomposing the composting material. The number of bacteria has no relation to the efficiency of composting, though it greatly correlates to the decomposition ratio. Bacterial growth activity that shows potential of bacterial growth was originally proposed. The influence of pH and the decomposition ratio on the growth activity has been studied. It was clarified that the bacterial growth activity is useful in evaluating the efficiency of composting and the maturity of produced compost.

Key words: composting, microorganisms, growth activity, pH, decomposition ratio