Production of amylase enzyme by Aspergillus and Fusarium species using sugar cane bagasse

Abstract

Amylases are hydrolytic enzymes produced by some microorganisms and utilized in the hydrolysis of starch. This study aimed to determine the ability of certain fungal isolates isolated from wastes to synthesize the amylase enzyme utilizing synthetic soluble starch and sugar cane bagasse as substrates. Aspergillus niger, Aspergillus flavus, and Fusarium spp., previously identified to have amylolytic activity, were used for the research. The submerged fermentation process was used to produce amylase, with basal medium and sugar cane bagasse as substrates. The incubation time, substrate and inoculum concentrations, pH, and temperature were all optimized. The dinitrosalicylic acid reagent (DNS) technique was used to determine the activity of the amylase generated. Initial production of amylase using soluble starch (20 g (w/v)) as substrate at room temperature and pH 7.0 shows that all the isolates produce amylase better when their concentration (3%) is high but have different incubation periods of 96 hr for Aspergillus niger (8.65±0.21 U/mL/minutes) and Fusarium spp (7.15±0.07 U/mL/minutes), while Aspergillus flavus (7.30±0.14 U/mL/minutes) requires an extended incubation period of 144 hr to produce the product. Further production using sugar cane bagasse and optimization of production parameters of the isolates reveals that Aspergillus niger (4.35±0.07 U/mL/minutes) has an optimum incubation period of 120 hours, an inoculum concentration and substrate concentration of 2% each, and a pH of 6, Aspergillus flavus (6.40±0.28 U/mL/minutes) has an optimum incubation period of 144 hours, with inoculum and substrate concentration of 3% each at neutral pH, Fusarium spp (6.80±0.28 U/mL/minutes) has an optimum incubation period of 168hr., inoculum concentration of 3%, substrate concentration of 2% and a neutral pH-7 and all the isolates have their best yield at temperature of 30℃. In conclusion, using cheap and readily available sugar cane bagasse can be a more cost-effective option for expensive synthetic starch substrates used in amylase synthesis. The study suggests further investigation into the isolates' identities and the extracted enzyme's industrial application.