ENHANCED POLYMETHYLGALACTURONASE PRODUCTION FROM ASPERGILLUS-NIGER-26BY CALCIUM ALGINATE IMMOBILIZATION

Spores of Aspergillus niger 26 were immobilised in calcium alginate an d the immobilised growing mycelium reused in batch mode for the produc tion of polymethylgalacturonase (PMG). The influence of alginate conce ntration, initial inoculum gel volume, spore concentration, and durati on of the fermentation cycle on enzyme activity and mycelium growth ar e reported. The best yield of PMG was reached with 5 mi initial gel vo lume 3% alginate concentration, 10(9) spores/ml gel and a cycle time o f 72 h. The optimisation of these factors, which affect the stability and productivity of the immobilised system, resulted in an increase in enzyme activity and the possibility of semicontinuous cultivation. (C ) 1998 Elsevier Science Ltd. All rights reserved.