Aging effect on enzyme activities in pressmud vermicasts of Lampito mauritii (Kinberg) and Eudrilus eugeniae (Kinberg)

Cellulase, amylase, invertase, protease and phosphatase activities in pressmud (PM; filter cake) and PM vermicasts of fresh, 15- and 30-day-old casts of Lampito mauritii and Eudrilus eugeniae decreased considerably with cast age. Enhancement of the activities of these enzymes could be ascribed to the nutrient-rich substrate, active microbial populations and optimal moisture conditions. Aged casts showed reduced enzyme activities because of a decreased moisture content, lower nutrient concentrations and a decline in microbial activity. Earthworm-microbe symbiosis seems to operate in a stepwise fashion, controlling groups of enzymes during the metabolism of PM to keep the flux of nutrients in casts (soil) in balance in the biosphere.