The production of sodium gluconate by enzymatic catalysis of delignified corn cob residue (DCCR) hydrolysate was studied. Penicillium oxalicum 11-13 was used for the production of cellulase with high beta-glucosidase activity. A fed-batch saccharification process was developed to obtain high yields of glucose. At the end of hydrolysis, the concentration of glucose reached 145.80 g/L. Glucose oxidase and catalase were co-immobilized to catalyze DCCR hydrolysate to produce sodium gluconate. Under the optimum conditions, 166.87 g/L sodium gluconate was obtained after 56 h of reaction, with a yield of 98.24%. The immobilized enzymes could still maintain more than 60% of the activity after repeated use for 6 times. This study provides a potential route for the production of valuable chemicals by enzymatic conversion of lignocellulosic materials. (C) 2017 Published by Elsevier Ltd.