Carbon and Nitrogen Sources Effect on Pectinase Synthesis by Aspergillus niger Under Submerged Fermentation

Abstract

Pectinases are the commercial enzymes that are abundantly employed in various industries like fruit juice industries for clarification, wine indutsry and paper industry for bleaching up pulp. The present work was done on culture conditions optimization for production of pectinases under submerged fermentation using wheat bran as a substrate. Fungal strains were isolated from vegetable waste dump yard soils of Warangal district of Telangana state and screened for their activity on pectin agar medium. Among 30 isolates, two fungal strains showed good activity and identified them as A. niger and A. flavus. The effects of the different carbon and nitrogen sources on pectinases viz. exo-PG, endo-PG, endo-PL and PME by A. niger with 1% wheat bran was carried out in submerged fermentation. These studies revealed that carbon and nitrogen sources have shown considerable influence on enzyme production. Among all the carbon sources tried, sucrose at 1% was shown to be efficient carbon source for all four types of pectinases under investigation. For endo-PG, endo-PL and PME maximum enzyme production were recorded on 8th day of incubation period but for exo-PG enhanced production was observed on 12th day. A. niger could not produce PME on 12th day from 2.50% to subsequent concentrations. Among nine different nitrogen sources were screened, maximum pectinase production was recorded in sodium nitrate at 0.2 % for A. niger. Endo-PG, endo-PL and PME maximum production were recorded on 8th day of incubation and for exo-PG maximum production was observed on 12th day. No PME production was observed in A. niger on 12th day.