Bioconversion of organic solid wastes into biofortified compost using a microbial consortium


Department of Microbiology, University of North Bengal, Siliguri, India


Purpose Urban municipal solid waste in India are 75–85% organic. Uncontrolled dumping of this waste is a major health concern. Degradation of organic waste by use of a microbial consortium is safe, efficient and economic. Therefore, this study was taken up to recycle the organic solid waste into effective compost using a microbial consortium. Methods Bacterial consortia were developed using antagonism assay. Concomitant enzyme production by the consortia was determined. The best consortium was further employed for degradation of 30 kg of organic solid waste. Compost analysis of 30 kg of wastes was done to determine the level of C, N, K, P and S. Results In this study, of the four consortia proposed, consortia no. 2 had the highest degrading capability. It exhibited consistent degrading capabilities of 30 kg waste. The volume of the waste was reduced to 82%, with a reduction in mass and moisture content to 65 and 42%, respectively, after 30 days of degradation study. The compost produced after 30 days had a dark colour and grainy texture without any crustacean population and lacked foul smell. Compost analysis of 30kg wastes inoculated with consortium 2 showed C:N ratio of 22:1 compared to 32:1 in control, and increased percentage of K, P and S which are required for enhancement of soil fertility. Conclusion Therefore, we can conclude that consortium 2 can serve as a biological tool for the removal of organic solid wastes from the environment, and the compost generated from the degradation can be applied to increase the fertility of the soil.