A pathway to enhanced organic waste decomposition by enzymatic response of earthworms in different vermibed substrates

Earthworms significantly enhance organic matter decomposition and nutrient cycling through gut enzymatic activity. This study investigates the digestive enzyme activities of Perionyx excavatus and Eudrilus eugeniae in different vermibed substrates- cow dung, horse dung, and a cow-horse dung mixture, to assess their impact on vermicomposting efficiency. Enzyme assays for amylase, cellulase, protease, lipase, urease, and phosphatase were performed. Results indicated significant variations (p < 0.05) in enzymatic activity across substrates, with the cow-horse dung mixture consistently yielding the highest activity. Eudrilus eugeniae exhibited peak enzyme activities, with protease (38.2 ± 3.2 µmol tyrosine released/min/mg protein) and amylase (27.1 ± 2.3 µmol/min/mg protein) being significantly higher in the mixed substrate. Similarly, Perionyx excavatus demonstrated enhanced enzyme activity in the cow-horse dung mixture. These findings suggest that mixed dung substrates optimize gut enzyme production, leading to efficient organic matter breakdown and improved vermicomposting highlights the role of substrate composition in enhancing vermiculture efficiency, offering valuable insights for sustainable organic waste management and soil enrichment.