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

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