Utilization of coffee pulp as a substrate for pectinase production by Aspergillus sp. VTMS through solid state fermentation

Abstract

offee pulp is an agro-industrial waste that has an abundant presence in Indonesia, up to 612.000 tons in 2018. Up to 6,5% of coffee pulp's dry weight is pectin. So, the coffee pulp has potential as a substrate for pectinase production. This study aims to acknowledge the utilization of coffee pulp for pectinase production using a solid-state fermentation method by Aspergillus sp. VTM5. Spore suspensions of Aspergillus sp. VTM5 with 108 spores/ml density are inoculated to coffee pulp substrate and incubated for 0 to 168 hours at 30°C. Characterization of pH testing with 250 µl of crude pectinase plus 250 µl of acetate buffer (pH 3-5) and phosphate buffer (pH 5.5-8). Enzyme activity assay using the Somogyi-Nelson Method. Optimum incubation time Aspergillus sp. VTM5 in producing pectinase is at 72 hours and the reducing sugar concentrations are 85,849 µg/ml. The optimum pH for pectinase activity is 4,5 and stable at pH 3-5. These results indicate that coffee pulp can be utilized as a substrate for pectinase production using a solid-state fermentation method by Aspergillus sp. VTM5. Purification of pectin content in the coffee pulp, purification, and characterization of the enzyme is needed to improve enzyme activity