Microbial Effectiveness through Vermicomposting Technique for the Biological Stabilization of Solid Waste

Abstract

Bacterial and fungal isolates were isolated and their effectiveness in composting on different substrates with the aid of earthworms Eisenia foetida (Red Wigglers) was performed at Nepal Academy of Science and Technology (NAST). Different parameters such as isolation of microorganisms, earthworm multiplication, composting effectiveness, analysis of micro-flora, their antimicrobial activity and nutrient content were performed. Bacteria such as Bacillus sp., Pseudomonas sp., Micrococcus sp., Azotobacter sp., Beijerinckia sp. were isolated, where as the fungal isolates include Aspergillus sp., Penicillium sp., Mucor sp., Rhizopus sp., Fusarium sp., Geotrichum sp. etc and the isolated actinomycetes were Streptomyces sp., Micromonospora sp etc. The treatment prepared by using the saw dust as a substrate and inoculation with Rhizobium sp. showed better for the earthworm multiplication, followed by biogas slurry with Rhizobium, Lantana camara with both Trichoderma and Rhizobium, Ageratina adenophora with both Trichoderma and Rhizobium and finally control. The treatment prepared from biogas slurry with inoculum Trichoderma + Rhizobium showed the fast composting and decomposition than other combinations. The harvested vermicomposts were higher in microbial diversity, nutrient content and showed effective antimicrobial activity towards different plant and human pathogens. Among treatments, the treatment prepared from Ageratina inoculated with the combination of Trichoderma and Rhizobium showed the higher increment of Potassium (K) content in comparison to the control. Similarly, Phosphorous (P) increment was found to be higher in the treatment with Lantana inoculated with both Trichoderma and Rhizobium sp. Likewise, Nitrogen (N) increment was found to be higher in Lantana inoculated with Rhizobium sp. In comparison to the control, organic matter was found to be in higher increment on Ageratina inoculated with both Trichoderma and Rhizobium sp. Composts formed from all these combination were found to be basic in nature.

J. Nat. Hist. Mus. Vol. 26, 2012: 126-135