Response surface optimization of tannase production by Aspergillus niger

Through single factor experiments,central composite design and response surface method,the conditions of producing tannase of Aspergillus niger were optimized.The most three important factors of determining the tannase production were tannic acid concentration,temperature and incubation time.The optimum conditions for enzyme production are as follows:temperature 31.7℃,speed 180 r/min,tannic acid concentration 1.5%,initial pH 6.0,inoculum 10%,bottle volume 20%,culture time 72 h.With these conditions,the fermentation tannase activity reached 1141.82 U /mL.