A forced-flow membrane reactor for transfructosylation using ceramic membrane

A forced‐flow membrane reactor system for transfructosylation was investigated using several ceramic membranes having different pore sizes. β‐Fructofuranosidase from Aspergillus niger ATCC 20611 was immobilized chemically to the inner surface of a ceramic membrane activated by a silane‐coupling reagent. Sucrose solution was forced through the ceramic membrane by crossflow filtration while transfructosylation took place. The saccharide composition of the product, which was a mixture of fructooligosaccharides (FOS), was a function of the permeate flux, which was easily controlled by pressure. Using 0.2 μm pore size of symmetric ceramic membrane, the volumetric productivity obtained was 3.87 kg m−3 s−1, which was 560 times higher than that in a reported batch system, with a short residence time of 11 s. The half‐life of the immobilized enzyme in the membrane was estimated to be 35 days by a long‐term operation. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 92–97, 2000.