Abstract:
The objectives of this research is to study the improvement compost quality by using cellulolytic and nitrogen fixing microorganisms. The research was conducted by the isolation of bacteria with cellulose utilization and N2 fixation from various sources at room temperature. Twelve bacterial strains were isolated from termites, soil from termites nests, composts compost accelerators, and decomposing materials. Among those strains, highly efficient cellulose producing and nitrogen fixing strains were selected. By determining CMC, filter paper, avicel, and alpha-cellulose degradating ability and acetylene reduction assay, strain no.5 was selected. The carbon sources, nitrogen sources, pH of the medium and incubation temperature affected on growth rate, cellulose degradating ability, and nitrogen fixing efficiency of this bacterium from the research, we found that strain no. 5 had high growth rate when cultured in the modium composed of glucose as a carbon source, peptone as a nitrogen source with optimal pH7 at 30°C. High cellulose degradating ability was found when cultured in the medium composed of CMC as a carbon source and peptone as a nitrogen source with optimal temperature and pH, 45°C and 7, respectively. And high nitrogen fixing efficiency was observed when cultured in nitrogen-free medium with glucose as a carbon source with optimal pH 7 at 30°C. The effect of strain no.5 on rice straw composting was also studied by comparing with untreated control. It was found that compost treated with bacterium gave significantly increase in nitrogen content more than untreated control (p<0.05), and C/N ratio in the two composts had significant difference, too, (p<0.05).