A DENSE CELL RETENTION CULTURE SYSTEM USING A STIRRED CERAMIC MEMBRANE REACTOR

A novel reactor design incorporating porous ceramic tubes into a stirr ed jar fermentor was developed. The stirred ceramic membrane reactor h as two ceramic tubular membrane units inside the vessel and maintains high filtration flux by alternating use for filtering and recovering f rom clogging. Each filter unit was linked for both extraction of cultu re broth and gas sparging. High permeability was maintained for long p eriods by applying the periodical control between filtering and air sp arging during the stirred retention culture of Saccharomyces cerevisia e. The ceramic filter aeration system increased the k(L)a to about fiv e times that of ordinary gas sparging. Using the automatic feeding and filtering system, cell mass concentration reached 207 g/L in a short time, while it was 64 g/L in a fed-batch culture. More than 99% of the growing cells were retained in the fermenter by the filtering culture . Both yield and productivity of cells were also increased by controll ing the feeding of fresh medium and filtering the supernatant of the d ense cell culture. (C) 1994 John Wiley and Sons, Inc.