Activities of Locally Formulated and Commercial Effective Microorganisms in Composting of Organic Solid Wastes

Abstract

This study was carried out to evaluate the effectiveness of locally formulated Effective Microorganisms (EM) in the degradation of organic solid wastes. The study was laid out in a Completely Randomized Block Design with three replicates each. The research was conducted at the Centre for Genetic Engineering and Biotechnology, Federal University of Technology, Minna, Nigeria between May 2015 and May 2016. Microorganisms were isolated from waste dumps and were identified as bacteria (Lactobacillus plantarum, Streptomyces griseus, Streptomyces rochei, Bacillus subtilis, Rhodopseudomonas palustris), moulds (Aspergillus oryzae, Aspergillus niger) and yeast (Saccharomyces cerevisiae). The microorganisms were used to formulate Effective microorganisms (EM-A and EM-B), which was applied for biodegradation of organic solid wastes in compost. The activities of the two EM brands were compared with that of commercial effective microorganisms (EM-C) using physicochemical and microbiological parameters during the composting process. The compost treated with EM-A attained the highest temperature of 58ºC. The pH of all the treatments was alkaline at the end of composting, while moisture contents were below 50%. The total aerobic heterotrophic bacterial counts (TAHBC) showed that the highest count of 3.0 × 107cfu/g was recorded in P1, Organic waste + EM-A on the 15th day of composting. The fungal counts varied among the treatments with the highest counts of 1.4 × 104 cfu/g recorded in P3, Organic waste + Commercial EM (EM-C) on the 15th day. Comparing the fertilizer value of compost obtained from the different treatments using their chemical properties, OF1 (Organic fertilizers with EM-A), had the best fertilizer value based on the N-P-K values (2.48 g/kg, 2.48 mg/kg and 2.51 cmol/kg respectively) and therefore, is most suitable for crop use. The activities of Effective microorganisms were responsible for the significant differences in physicochemical and microbiological parameters.