Synthesis of variable enzyme spectrum by immobilized mycelium of A. niger

The influence of different carbohydrate and nitrogen sources on the extracellular enzyme spectrum (polygalacturonase, pectinesterase, cellulase, alpha -amylase) produced by submerged culture of immobilized mycelium of A. niger has been studied. Due to its particular importance to fruit and vegetable processing special attention has been drawn to the ratio of polygalacturonase (PG): pectinesterase (PE). Glucose as well as sucrose, raw sugar and lactose have been found to be especially suitable as carbon sources to obtain a high averge specific PG production rate (K super(-)p sub(PG)). In order to achieve a high PG/PE quotient the use of C-sources glucose, sucrose and extract of sugar beet shreds as well as the N-sources (NH sub(4)) sub(2)SO sub(4) and yeast extract are preferable. To achieve a low quotient the application of lactose, extract of apple pomace and apple pulp (C-source) as well as KNO sub(3), NaNO sub(3), peptone or cornsteep liquor (N-source) is recommended.