New method of immobilization of microbial cells by capture on the surface of insoluble pyridinium‐type resin

A new method for the immobilization of microbial cells has been developed. Whole cells of Escherichia coli with aspartase activity were immobilized by capture on the surface of cross-linked poly(N-benzyl-4-vinylpyridinium bromide) containing styrene (BVPS resin), an insoluble pyridinium-type resin. When a suspension of the bacterial cells in buffer solution was passed through a glass column containing beads of BVPS resin, the cells were captured on the resin surface and formed an immobilized cell system. A fixed-bed column reactor containing 300 mg of the bacterial cells immobilized by capture on 10 g of BVPS resin beads was used for the preparation of L-aspartic acid from ammonium fumarate. Continuous operation of tne bioreactor produced L-aspartic acid in a quantitative yield when the influent substrate concentration was 0.1M and the flow rate was 0.41-0.83 bed volumes per hour at pH 7.4-7.7 at 30 degrees C.