PRODUCTION AND OPTIMIZATION OF AMYLASE, CELLULASE AND PECTINASE BY SELECTED BACTERIA AND FUNGI USING YAM PEELS AND CASSAVA PEELS AS A SUBSTRATE

Abstract

ABSTRACT Everyday large amount of waste material is lodged into the environment by industries, agriculture farm land and other ways leading to environmental pollution and these wastes materials from different sources can be dangerous to man. However, not much work has been done on utilization of these wastes (agricultural wastes) to generate useful products which necessitated this study. Agricultural wastes such as yam peels and cassava peels were used as solid substrate on solid state fermentation for the production of amylase, cellulase and pectinase. Isolation and identification of Lactobacillus bulgaricus, Saccharomyces cereviciae, Aspergillus niger and Zynomonas mobilis from milk, fresh palm wine, soil and spoilt orange sample respectively were done, Biochemical and molecular identification of the test organisms were carried out. The organisms were screened for enzymatic activity, the organisms were assayed at different incubation period, different optimum condition such as temperature, pH and substrate concentration were also performed. The result revealed a clear zone of inhibition in the agar plates. The highest amylase activity was obtained on the 4th day (8.5×10-2 mg/ml/sec.) by Aspergillus niger using cassava peels as a substrate. The highest cellulase activity (4×10-3 mg/ml/sec.) was obtained on the 4th by Aspergillus niger using cassava peels. The highest pectinase activity was obtained on the 4th day (3.7×10-2 mg/ml/sec.) by Aspergillus niger using yam peels as a substrate. The optimum pH for cellulase production was at pH 6 with the highest enzyme activity of (3.5×10-4 mg/ml/sec.) by Aspergillus niger using yam peels as a substrate, the optimum pH for cellulase activity was at pH 6 with the highest activity of (2.7×10-2 mg/ml/sec.) by Aspergillus niger using yam peels as a substrate. The optimum pH for pectinase activity was at pH 7 with the highest activity of (2.6×10-2 mg/ml/sec.) by Aspergillus niger the optimum temperature was at 50 °C with the highest activity (8.5×10-2 mg/ml/sec.) by Aspergillus niger using cassava peels as a substrate. The optimum pH for cellulase enzyme activity was 60°C. With the highest activity of (1.7x104 mg/ml/sec.) using cassava peels as a substrate. For pectinase production the optimum temperature of 50 °C gave the highest pectinase activity of 1.5x10-2 mg/ml/sec. Substrate concentration for amylase cellulase and pectinase activity were also determined, points of saturation occurred between 2.5 % to 3 % in all the organisms tested Aspergillus niger have the highest concentration of substrate. This study revealed that all the test isolates using agro wastes as a substrate have the ability to produce amylase, cellulase and pectinase, hence it may be considered as a source for the production of industrial amylase, cellulase and pectinase. Serious work should be done on the abundant of agro wastes that are generated annually in Nigeria which could be utilized for the production of enzymes.