Optimization of Tannase Production from Waste Tea Extract from Asp.niger B1401

Using waste tea residue as raw material and Aspergillus niger as fermentation starter,tannase was produced by liquid-state shake flask fermentation.The optimal conditions were determined by single factor experiments test,Plackett-Burman test and Box-Behnken response surface method.Results showed that the optimum conditions for the liquid-state fermentation by Aspergillus niger were:6% tannic acid:3% tea polyphenols as mixed inducer,0.746%soluble starch:0.254%sucrose as mixed carbon source,0.3%urea:0.7%sodium nitrate as mixed nitrogen source,inoculum size 1%,medium contents 90 mL/250 mL,rotating speeds 140 r·min^-1,temperature 30 ℃,the fermentation time for 72 h,the tannase activity reached 104.82 U/g.