isolation of pectinases from aspergillus niger to improve the fermentation process of iranian tea leave

fermentation is an important process for black tea production. during this process, by exposure of substrate to enzymes and the underlying oxidation reactions, quality determining factors of tea is produced. it is known that the exogenous application of cell-wall degrading enzymes leads to the increased production of these compounds through enhancement of enzyme-substrate interactions. pectinases in an important enzyme in this regard which is produced by microorganisms like genera of aspergillus. in the present study, pectin lyase was isolated and partially purified through three- phase partitioning method from aspergillus niger. the enzyme was purified by 16.65- fold from aspergillus niger. the yield of purification was 52%. to assay the effects of purified enzymes on some qualitative characteristics of tea, crude and purified enzyme were sprayed in the fermentation stage of tea. molecular weight, optimum ph and optimum temperature of enzyme were 12kda, 8 and 40°c, respectively. results showed the effect of crude enzyme preparation on qualitative characteristics of tea is more than purified enzyme.