STUDY ON THE MICROFILTRATION OF ESCHERICHIA COLI-CONTAINING FERMENTATION BROTH BY A CERAMIC MEMBRANE-FILTER

Microfiltration (MF) of a fermentation broth containing Escherichia co li is reported in this article. We used a ceramic membrane filter (zir conia on sintered carbon) having a nominal pore size of 0.2 mu m. Our results indicate that the filtration resistance was mainly caused by t he cake formed on the membrane surface. Both transmembrane pressure (T MP) and fluid sweeping velocity influenced this cake resistance. Resis tances due to membrane itself and due to internal pore blockage by E. coli were less important and insensitive to both TMP and fluid sweepin g velocity. Preliminary results also showed that the cell density coul d be significantly increased when we connected such a ceramic filter o n-line with our fermentation system. In particular it was found that t he gas bubbles entrained in the broth side of the filter could increas e the filtration flux by as much as 80%.