Production and Application of Epigallocatechin Gallate Hydrolase
|Keywords||Tea polyphenols EGCG EGC Aspergillus niger Aspergillus oryzae Hydrolase|
Collectively, of the polyphenols is a polyphenol compounds having good biological activity, such as anti-oxidant activity, anti-tumor and anti-mutant performance. In vivo as reactive oxygen radical scavenger, can reduce the incidence of diseases such as cancer, coronary heart disease and atherosclerosis. There are five major tea polyphenol ingredient in green tea. As different structures polyphenols monomers having different physiological activity, and therefore to more effective use of the various monomers, and development of new drugs on the basis of the monomer, and giving full play to the respective utility, purification, separation or synthesis of polyphenols monomer is particularly important. Due to the low yield chemical synthesis and byproducts, separation and purification difficult, and thus far, most studies are separated from the tea extract and purified EGCG' dissertation">EGCG. On table epigallocatechin (EGC), due to the low content of EGC tea, accounting for about 5% of the total tea polyphenols of green tea, even if the efficiency of the extraction and separation again, production is still constrained. Table Gallic epigallocatechin gallate (EGCG) as the main component of green tea polyphenols, EGC and gallic acid (GA) to form esters. Therefore, if we agree to hydrolysis technology will EGCG hydrolysis of EGC and GA will have a very important market prospects. Currently, some studies with a conventional chemical treatment of the acid and base hydrolysis EGCG, but the hydrolysis rate, and EGCG and EGC is unstable under alkaline conditions, and can easily be oxidized. To date, less the biotransformation of tea polyphenols low conversion rate, existing research exists, the complexity of the production process as well as shortcomings of EGCG and EGC unstable under the transformation conditions. Therefore, the establishment of an EGCG into EGC stable and efficient production methods become particularly important and urgent. In this study, a use of biological the enzyme catalytic EGCG hydrolysis production EGC. In this study, fully taking into account the characteristics of EGCG is stable in acidic conditions, first select a suitable acidic conditions develop enzyme producing fungi; Aspergillus niger, Aspergillus oryzae and Trichoderma reesei as enzyme production strains by Add EGCG and olive oil-induced enzyme production, expectations induced catalytic production EGC EGCG hydrolase, resulting in the best production strains. Studies by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) analysis verified the product and substrate in the hydrolysis reaction system. Screened the EGCG-hydrolase strains of Aspergillus oryzae and Aspergillus niger, both by the medium supplemented with EGCG induced EGCG hydrolase; without adding any inducer of fermentation broth and add the olive oil EGCG hydrolase activity; Richter Trichoderma does not have the ability to produce EGCG hydrolase. Since then, production EGCG hydrolase strains of Aspergillus niger and Aspergillus oryzae two further research and study. Added and the amount of EGCG on cell growth and metabolism and enzyme production, and the establishment of the enzyme assay method and enzyme-catalyzed hydrolysis reaction system to determine the the best fermentation for enzyme production time and get the best EGCG add concentration to optimize the conditions for enzyme production. Experimental results show that the respective detection indicators showed significant variation; increase of EGCG concentration. EGCG higher the concentration, the lower the pH-value level, the higher the residual sugar content, the greater the cell amount; The later time and the maximum value of each index; protein content and hydrolase activity trends, Aspergillus niger, and m Aspergillus vary. Consolidated volume of enzyme activity, several indicators than the yield of enzyme activity and enzyme inducing effects of EGCG concentration found the Aspergillus niger inducer concentration of 2.5-7.5 mg / mL the Aspergillus oryzae compared to 10.0 mg / mL, easier to induce and Aspergillus niger.