ISSN: 2471-9315
Doughari JH and Onyebarachi GC
Polygalacturonase is a pectinolytic enzyme that catalyzes the hydrolytic cleavage of the polygalacturonic backbone linkage chain. In this study, polygalacturonase was produced from Aspergillus flavus isolated from an orange waste dump site. Production was carried out in solid state fermentation. Optimum production of polygalacturonase was found at incubation period of 96 h, pH 4.5 and at 35°C using ammonium sulphate, orange peel as best nitrogen and carbon sources, respectively. The enzyme was precipitated with 60% ethanol resulting in 3.54 fold purification, and purification of the enzyme with Sephadex G-75 resulted in 9.93 fold. The purified enzyme showed maximum activity in the presence of polygalacturonic acid at 35°C and pH 4.5, while for sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, molecular weight obtained was 66 KDa. The Km and Vmax value of the enzyme were found to be 0.705 mg/mL and 1.0508 μmoL/min, respectively. The addition of metal chlorides and inhibitors reduced the enzyme activity. Based on the physicochemical properties of the purified enzyme, this enzyme possesses great potential for industrial and biotechnological applications such as fruit clarifications and oil extraction.