Response Surface Optimization of Vat Blue 4 Degradation Process Using Pseudomonas aeruginosa WYT

Vat Blue 4, one of the anthraquinone dyes, were widely used in printing and dyeing industry due to bright color and low price. However, low utilization rate and improper handling lead a large number of dyes discharged into environment with wastewater. But few research report the Vat Blue 4 degradation by bacteria, perhaps too complex structure to biodegraded. In this work, we isolate a new strain Pseudomonas aeruginosa WYT which could degrade Vat Blue 4, and the degradation rate is low and unstable. To overcome this shortcoming, single factor and response surface experiments were designed to optimize its culture conditions. The optimal conditions of Pseudomonas aeruginosa WYT degradation of VB4 were obtained through this: temperature 35.0C, initial biomass 0.06, pH 7.0, glucose 1.0 g/L, urea 1.0 g/L, VB4 50 mg/L and 2 mL/L trace salt. Under these optimized conditions, the maximum degradation rate increased from initial 85% to 97%.