Hydrolysis of corn cob performed for 6 h with 0.5 N NaOH at solid/liquid ratio of 0.084 g/g allowed obtaining a hydrolyzate containing 1171 +/- 34 mg/l ferulic acid and 2156 +/- 63 mg/l p-coumaric acid that was used as a medium for vanillin bioproduction by the engineered strain Escherichia coli JM109/pBB1. Aiming at maximizing vanillin bioproduction, the effects of medium heat sterilization, one-stage or two-stage pre-cultivation, adaptation of the microorganism to the hydrolyzate and inoculum biomass level were investigated. Biomass pre-cultivated once in unsterilized hydrolyzate was able to effectively convert ferulic and p-coumaric acids to a mixture of vanillin, vanillic acid and vanillyl alcohol provided with the typical vanilla flavor. At initial biomass concentration of 0.5 g(DM)/l, maximum values of vanillin concentration (239 +/- 15 mg/l), vanillin yield on consumed ferulic acid (0.66 +/- 0.03 mol/mol) and vanillin volumetric productivity (10.9 +/- 0.7 mg/lh) were obtained after 22 h. (C) 2008 Elsevier Inc. All rights reserved.