Production of Cellulase and Protease from Microorganisms Isolated from Gut of Archachatina marginata (Giant African Snail)

Abstract

Cellulase and protease producing microorganisms were isolated from the gut of Archachatina marginata (Giant African snail). The microorganisms isolated were Bacillus subtilis, Staphylococcus aureus, Streptococcus casseliflavus, Streptococcus faecalis, Aspergillus flavus, Rhizopus sp, Fusarium sp. and Aspergillus niger. When the isolates were tested on skimmed milk agar (1%) and Carboxymethyl Cellulase, B. subtilis and A. niger were the best producing microorganisms for both cellulase and protease enzyme. For cellulase production, B. subtilis revealed its highest biomass yield after 24 hours of incubation with activity of 0.62mg/ml/secˉ4 at 80℃ and pH of 5. Aspergillus niger showed its highest biomass yield after 5 days with an activity of 0.74mg/ml/secˉ4 and an optimum temperature of 60℃ and the optimum pH was 5. For protease production, B. subtilis was grown for 30 hours; its highest biomass yield was after 18 hours with an enzyme activity of 2.95μg/ml/secˉ4 and an optimum temperature of 60℃, while A. niger was grown for 7 days and showed highest yield after 6 days with enzymatic activity of 3.14μg/ml/secˉ4, and an optimum temperature of 50℃. The optimum pH was at 7 and 8 for B. subtilis and A. niger respectively. The results from this study suggest that B. subtilis and A. niger can be harnessed for the production of cellulase and protease.