Optimization of the production of tannase by Aspergillus niger solid-state fermentation using gall nut

The systematic name of Tannase is tannin acylhydrolase(Tannase,the EC 3.1.1.20);it can hydrolyses the ester and depside bonds of gallotannis and gallic acid esters to form glucose and gallic acid.Tannase was mainly produced by microbiology,existing inside and outside of the cell.Penicillium and Aspergillus Niger were mostly studied.This experiment was focused on optimizing fermentation conditions by Aspergillus Niger in solid-state fermentation using gall nuts as substrate.The initial moisture was 80 %,the inoculum 1% and the 30 C was the best conditions by the single factor optimization experiment.Furthermore,orthogonal optimization of the medium and the culture was performed and the best conditions of producing tannase by solid fermentation were:the initial moisture content 80 %,the inoculum 1%,the temperature 33℃ and the gall nuts 15%.Among them,the temperature had a remarkable effect on Tannase activities.The activity of Tannase was up to 57.32U/gds under the above condition.