Abstract
For production of vanillic acid from vanillin, optimum culture conditions for Pseudomo- nas sp. GD-088, having vanillin-oxidizing activity were investigated. The highest vanillin-oxidizing activity was obtained when this strain was cultured at 30$\circ$C for 24 hr in a medium consisting of 3.0 g/l xylose and 0.46 g/l NH$_{4}$CI (pH 7.0). When 18 g/l of whole Pseudomonas sp. GD-088 cells as the enzyme source was used in 50 mM phosphate buffer (pH 7.0) containing 3.0 g/l of vanillin, 2.463 g/l of vanillic acid was produced for 40 minutes. This amount of vanillic acid corresponds to a 90% yield, based on vanillin.