PRODUCTION OF AMYLASE, CELLULASE AND PROTEASE BY OYSTER MUSHROOM (PLEUROTUS OSTREATUS) ON SOME AGRICULTURAL WASTES.

Abstract

The ability of the edible mushroom Pleurotus ostreatus to produce extra cellular enzymesof industrial importance - Beta-amylase, Alpha-amylase, Protease and Cellulase were monitored using readily available agricultural wastes namely, sawdust, rice bran, wheat bran and palm kernel peri carp in submerged fermentation .Fresh fruiting body of Pleurotus ostreatus was collected and identified using standard method. Tissue culture technique was employed in obtaining active mycelium of the mushroom from its fresh fruiting body. Proximate and mineral compositions of the agricultural wastes were determined before and after fermentation. The composition of the wastes was observed to affect the quantity as well as the activity of the enzyme assayed. Rice bran had the highest beta-amylase activity of 220llmollminlml between 48 and 72hours of fermentation and it was used for further experiment. The beta-amylase isolated from Pleurotus ostreatus was purified by ion exchange chromatography on DEAE Sephadex A- 50 and Gel filtration G-150. The effect of variation in pH, temperature and different salts on the activity of the enzyme was investigated. The optimum pH was recorded to be 5.5 while optimum temperature was 55°C. Salts namely CaCI2, CUS04, NaCl, EDTA, MgClz and HgCh was observed to have inhibitory effect on the activity of the enzymes with the highest inhibition recorded with HgCI and EDTA while CaCh has least inhibitory effect on the enzyme. The Michaelis-menten constant, Km, was 3.57umol/minlml while the maximum velocity Vmax, was 0.21 umole/min/ml The low Km values, physicochemical properties and improved activities of ~-amylase from the mushroom Pleurotus ostreatus makes it a more favoured alternative to ~-amylase from other microorganisms for industrial scale applications.