PRODUCTION OF POLYGALACTURONASES FROM KLUYVEROMYCES-MARXIANUS FERMENTATION - PRELIMINARY PROCESS DESIGN AND ECONOMICS

A simple one-stage purification scheme for the recovery of polygalacturonase from K. marxianus fermentation is described. The optimum pH for ion exchange is 4.5, which, being compatible with the fermentation conditions, means that the broth can be centrifuged and directly applied to an ion-exchange column; the process gives more than 90% recovery of a highly purified enzyme. Economic analysis of a repeated batch process shows that recovery of other by-products (cells and ethanol) is only of marginal importance, whilst pectinase production is highly profitable. There are strong economies of scale, up to a fermentation batch scale of around 20 m3, with 100 batches per year. Under typical conditions our analysis predicts a payback time of under a year.