Journal article Open Access
Aruna A.P1, Purushothaman Balakrishnan1,2, Kumaran Shanmugam1, K. Rajendran1*
There are number of techniques being used to convert the organic waste into the useful products like bio fuel, manure etc. Among them, the mesophilic process using earthworms, vermicomposting is the most effective and low cost process to convert large amount of organic waste in relatively shorter time.The significance of the process is not only to improve the fertility of the soil but also to improve the diversity of beneficial microorganisms in the soil.The process also eradicate harmful microbes from the ecosystem. The current study is to investigate the presence, range and diversity of microbial population in vermicast fed with different raw materials like cow dung, biomethanisation plant slurry, and press-mud). The vermicomposting unit at the Periyar Maniammai University, Vallam, Thanjavur, Tamil Nadu, India was the study area where open bed method is followed. Six samples were tested for this study, three for composts and three for vermicompost from the same raw materials.After inoculating earthworms, samples were collected on the 42nd day of the process. Samples from composting beds were collected at 90th day and proceeded to the metagenomic analysis.The sequence results were categorized from higher order phylum to lower order species level and the report indicates microbes like Bacteroidetes, Proteobacteria etc., were present in larger quantity in all the vermicompost samples compared to compost samples. The results indicate vermicompost obtained from the biomethanisation slurry did not have any pathogenic bacteria like Salmonella spp., Escherichia coli, Enterobacter spp., and Enterococcus spp despite night soil being one of the components used in the plant. In contrast, it had maximum number of bacteria species useful for the plant growth than other samples in our study.