Monitoring of microbial populations and their cellulolytic activities during the composting of municipal solid wastes

Seasonal changes in microbial populations and the activities of cellulolyti c enzymes were investigated during the composting of municipal solid wastes at Damietta compost plant, Egypt. The changes in temperature, pH and carbo n/nitrogen (C/N) ratio were also monitored. The results obtained showed tha t the temperatures of the windrows in all seasons reached the maximum after 3 weeks of composting and then decreased by the end of the composting peri od (35 days), but did not reach ambient temperature. Marked changes in pH v alues of the composts in all seasons were found, but generally, the pH was near neutrality. Significant increases in the size of the microbial populat ions were obtained in autumn and spring seasons compared to summer and wint er seasons. The activities of cellulases were also higher in the autumn and spring seasons than in the summer and winter seasons. The decrease in C/N ratio in autumn and spring was higher than in summer and winter. It was evi dent that the degradation of organic matter increased by an increase in the microflora and its cellulolytic activities.