BIOPROCESS OPTIMIZATION OF ASPERGILLUS NIGER AL1 (MK849882) GROWN ON CASSAVA PEEL FOR THE PRODUCTION OF AMYLASE USING SOLID STATE FERMENTATION

Abstract

Background and aim: Amylase is an enzyme in the group of hydrolases that split the glycosidic bonds present in polysaccharides thereby breaking them into simple units. This enzyme found application in many sectors of the economy such as medical, pharmaceuticals and industrials. The objective of the present study was the production, partial purification and kinetic study on amylase using Aspergillus niger grown on cassava peel as the sole carbon source through solid state fermentation. Fungi were isolated from deteriorating cassava peel under laboratory conditions; isolates were identified by their colonial morphology and molecular technique and screened for amylolytic ability. Solid state fermentation of the cassava peel and optimization of culture parameters were done for amylase production, the crude amylase was assayed using the DNSA method, partial purification and characterization were carried out by the ammonium sulphate precipitation, dialysis and gel filtration techniques. Isolate with the highest amylolytic ability was confirmed through the sequenced 18S rRNA as Aspergillus niger strain AL1 (MK849882). Best conditions for maximum amylase activity (629.36±12.21 mg/ml/min) were 120 hours of incubation, pH of 7.2, temperature of 50 0 C, moisture content of 15ml, inoculum size of 1.5 ml, substrate concentration of 20 g, supplementing with 3 % glucose and the use of basal medium. Purification of the crude enzyme yields amylase with 0.77 fold increase with specific activity of 7.00 U/mg and 5.98% protein. The Aspergillus niger strain AL1 (MK849882) could be a potential fungus for local amylase production in the bid to convert waste to wealth.