Assessment of enzyme activities and microbial populations in normal compost and vermicompost

Changes in extracellular enzyme activities and microbial populations were studied during normal compost and vermicomposting process of fruit pulp, vegetable and groundnut waste and cow dung. The microbial numbers and their extracellular enzyme profiles showed relative variation and were found increasingly more abundant in vermicompost than in normal compost leading to the conversion of agricultural waste into value added product. In vermicompost, the maximum enzyme activities (cellulase, Amylase and protease) were observed during 21-35 days. The cellulase and protease activities of vermicompost reached the maximum values by 28th day 1175, 825 +g reducing sugar g-1 hr-1 of vermicompost samples. Some of the enzymes showed correlation with change in number and types of different microbial groups like bacteria, fungi and actinomycetes during vermicomposting with maximum number of 126 x 106, 28 x 104 and 93 x 105 CFU g-1 sample respectively. In contrast delayed greatest enzyme activities were observed on 42-49th day i.e., last days of normal composting. Earthworms stimulated biochemical activity and nutrient cycling by 40-45% contributing to the reduction of period of degradation of agricultural wastes resulting in maturation of vermicompost by 28th day.