The effects of carbonates removal on adsorption, immobilization and activity of cellulase in a calcareous soil

Enzymes are able to be sorbed and immobilized by clay minerals and humic colloids in soil environments. The present study was done to elucidate the effects of soil innate carbonates on the sorption, immobilization and activity of cellulase in a calcareous soil by treating it with different levels of acetic acid. The study of adsorption isotherm revealed that soil carbonates removal with acetic acid increased the intensity of cellulase adsorption (1/n) estimated by the Freundlich model. Based on the Freundlich isotherm model it is predicted that cellulase molecules will be increasingly adsorbed on acetic acid treated soil with increasing cellulase concentration. However, practically the amounts of cellulase protein adsorbed and immobilized on untreated soil with high levels of ECC were significantly higher than those on acetic acid treated soils. The immobilized cellulase activity and particularly its specific activity decreased considerably with increasing carbonate contents in soil.