Partial Purification and Biochemical Characterization of Extracellular Pectinase from Aspergillus Niger Isolated from Groundnut Seeds

To produce and partially purify pectinases from Aspergillus niger isolateJGIm2, characterize the enzymes for potential industrial applications in clarifying fruit juices. Methodology and results: Isolates of Aspergillus niger were screened for ability to produce pectinases by the enzymatic index method. All the 34 isolates screened were producers with isolates JGIm2, JGIm3 and JGIm5 being the best. Optimum enzyme production was found with medium containing 1.5% pectin after 48 h of fermentation. Partial purification of the enzyme was carried out by ethanol precipitation to give two fold purification and 56% yield. The enzyme had pH & temperature optima of 4.0 and 45°C, Km and Vmax values of 0.178 g/dl & 11.62 IU/mg protein, respectively. Clarification of banana and pineapple juice using the partially purified enzyme resulted in 38 and 41% reduction in viscosity as determined spectroscopically