A simple method for immobilizing cells of Acetobacter suboxydans by adsorption on inorganic sintered glass carriers is described. The immobilized cell preparations exhibited 100% of the initial activity when converting D-sorbit to L-sorbose. This sintered glass was used in a fixed-bed loop reactor with a working volume of 0.21 for semicontinuous and continuous experiments. A prolonged working life span was achieved, which could possibly satisfy requirements for scaled-up operations.