Bacterial Groups Concerned with Maturing Process in Manure Production Analyzed by a Method Based on Restriction Fragment Length Polymorphism Analysis

Abstract

Composting is a biological aerobic decomposition process consisted from different phases. Although the Japanese Standards for manure recommended that it took at least 6 months to complete the maturing phase, there was no reliable ground. In order to find out shortening method of the maturing phase, the microorganisms concerned with a progress of the maturing was determined by using the most probable number method (MPN) and PCR-RFLP of the 16S rDNA, which was found effective to provide numbers and taxonomy of polymyxin B resistant bacterial groups in the former paper [1] . Compared to the numbers after thermophilic phase, those of Actinobacteria, δ -proteobacteria, and the other gram negative bacteria increased to 50 times, 20 times, and 10 5 times, respectively, after maturing phase, while those of Bacillus spp., and α and β -proteobacteria decreased to 1/10, and 1/10 5 after maturing phase. Numbers of the other Fumicutes, and γ -proteobacteria remained in the same revel. Actinobacteria, δ -proteobacteria, and the other gram negative bacteria might be concerned with a progress of the maturing phase, because these bacterial groups were detected and enumerated due to their proliferation ability. Although number of Acitinobacteria might be underestimated because of a PCR bias, the method was found effective for the purpose to monitor bacteria actively proliferated in culture medium.