Study On Fermentation Optimization Of Penicillium Sclerotiorum And Enzymatic Properties Of Tannase

Tannase(E.C.3.11.20)commonly referred to as Tannin Acyl Hydrolase.Tannase catalyzes the ester bond,the phenol bond and the glycoside bond in the tannin molecule,and produce glucose,gallic acid and other alcohols.In addition,tannase has the characteristics of catalyzes esters-catechins in tea into simple catechins,catalyzes gallicin and synthesis of propylgallate.Tannase has important application in food,chemical,feed,medicine industry.In this study,we found that sclerotium penicillium AHAUCHA 001,endophytic fungi of tea plant,has the ability to produce tannase,the optimization of fermentation conditions were studied,the tannase producted by sclerotium penicillium AHAUCHA 001 are partially purified and its enzymatic properties are studied.The results are as follows.The fermentation conditions and the culture medium of tannase production by AHAUCHA001 were optimized by single factor experiment.After analysis,the optimal fermentation and the culture medium conditions for tannase production by solid fermentation were determined as follows:growth cycle 72h,28?,the pH of salt solution 6.0,the content of gallnut 40%,2%(w/v)of ammonium chloride as extra nitrogen source,inoculum size 2%(4×10~7/m1),the enzyme activity of AHAUCHA 001 was 131.01 U/g dried fermentation solid medium in this circumstance,with enzyme activity enhanced by 626%.The optimal culture medium for enzyme production by liquid fermentation were determined as follow:growth cycle 72h,28?,the pH of salt solution 6.0,Tannic acid addition 1%(w/v),sodium nitrate 0.4%(w/v)as sole nitrogen source,soluble starch 2%(w/v)as extra carbon source,180 r/min.the enzyme activity of AHAUCHA 001 was 42.11 U/g dried fermentation solid medium in this circumstance,with enzyme activity enhanced by 1220%.Compared with the report,this study showed that,under the best conditions,penicillium Sclerotiorum AHAUCHA 001 was a kind of production strain of tannase with practical value.The final enzyme activity recovery was 16.84%and the purification multiple was 4.77 by using ammonium sulfate precipitation,glucan gel G-100 chromatography and DEAE-cellulose ion exchange chromatography purified.Characterization of tannase research show that the tannase product by sclerotium penicillium AHAUCHA 001 showed well stability.Tannase activity was optimal at 40?.The optimal pH of the tannase is 5.0 and showed well stability in pH5.0-7.0.The Km was 0.929mmol/L,and the Vmax was 102.041?mol/L·min.Organic solvents have a certain effect on the activity of tannase.To a certain extent,all the organic solvents reduce the activity of tannase expect acetone,and the inhibitory effect of glycerol is the most obvious for the 19.87%inhibition rate.Compared with the report,this study showed that,under the best conditions,penicilliumSclerotiorum AHAUCHA 001 was a kind of production strain of tannase with practical value.