Denaturing gradient gel electrophoresis analyses of microbial community from field-scale composter

The diversity of microbial community during the decomposition of waste in a held-scale composter (Hazaka system) was investigated by denaturing gradie nt gel electrophoresis (DGGE). The composter operates at a high temperature through a self-heating system, creating a thermophilic (60-76 degreesC) st age during the initial phase acid a mesophilic (45 degreesC) stage towards the later phase of the composting period. The pH of the system (pH 7.75-8.1 0) did not vary significantly during the process while moisture content was reduced from 48.8% to 25.1%. DGGE and 16S rDNA analyses showed that the fo llowing genera were found throughout the process: Propionibacterium sp., Me thylobacterium sp., Pseudomonas sp., and Bradyrhizobium sp. Different Bacil lus spp. thrive at the thermophilic or the mesophilic stage while Clostridi um sp. was only found at the initial phase of the process. Staphylococcus s p. and Caulobacter sp. or Brevundimonas sp. existed during the later phase of the composting period.