Condition of tannase production from Aspergillus niger T4-3 under uncooked material fermentation

The condition of tannase production by a strain of Aspergillus niger T4-3, which was screened, 60 Co-induced mutation by the laboratory, under uncooked fermentation using tannic acid was studied. On the basis of single factor test in order to obtain the optimal conditions for tannase production, orthogonal tests were done. The result showed that the effect of the tannase activity was the liquid-solid ratioaddition of tannic acidnitrogen sourceaddition of MnCl 2 substrate content. The optimum conditions were: nitrogen source beef extract, addition of tannic acid 4.8%, CaCl 2 0.3%, MnCl 2 0.3%, liqid-solid ratio 1:1.6, substrate content 15 g, and culture temperature 30 ℃. The maximum tannase activity was up to 166.4 U/gds under these conditions, approximately 3.3-fold higher than that of basis medium.