APPLICATION OF A ROTATING CERAMIC MEMBRANE TO DENSE CELL-CULTURE

The effects of fine bubbles on the separation performance of a rotating ceramic membrane were examined using aerated and unaerated yeast cell suspensions. The permeation flux of the aerated cell suspension was much higher compared with that of the unaerated cell suspension. Fine bubbles that accumulated around the ceramic membrane were found to prevent the compression of a cake layer, thereby resulting in a reduction of the filtration resistance. To investigate the possibility of long-term operation of the rotating ceramic membrane, dense cell perfusion cultures of wild strains of Corynebacterium glutamicum and Propionibacterium freudenreichii were carried out in a jar fermentor coupled with the rotating ceramic membrane module. During these long-term perfusion cultures no serious membrane-fouling problem was observed. The final cell concentrations attained with C. glutamicum and P. freudenreichii were 120 g-dry cell/dm3 and 53 g-dry cell/dm3, respectively.