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β-glucosidase enzyme, also known as β-D-glucoside glucohydrolase enzyme hydrolyzable coupled to the terminal non-reducing beta-D-glycosidic bond, while the release of β-D-glucose and the corresponding ligand. It is the rate-limiting enzyme of cellulose degradation is concerned, has been used in many ways: to improve the flavor of the tea, juices, production Gentiooligosaccharide the activity of soy isoflavone aglycone, natural pigment Gardenia Blue and natural antioxidant polyphenolic compounds, and the like. The main topic for the screening of β-glucosidase, optimization of fermentation conditions, the four aspects of the enzymatic properties and related gene cloning as research: application of β-glucosidase hydrolysis the geniposide generate Geniposide $ geniposide $ can be cross-linked in the case of primary amino acids exist gardenia blue principle, design the rapid screening of strains producing β-glucosidase medium, and preserved several strains were screened, elected β - glucosidase production of oxalic acid from Penicillium strains. Single factor optimization method oxalicum fermentation process temperature, pH, liquid volume, carbon sources, nitrogen sources, inorganic salts, and the surface active agent and a stimulating agent, and the use of uniform design method of affecting carbon source, a nitrogen source, inorganic salts and a surface active agent in an amount ratio by DPS (Data Processing System) software regression analysis, to obtain a fermentation of Penicillium oxalicum optimum conditions of production of β-glucosidase as: bran 4%, beef extract 0.2%, 0.1% NaCl, the CuSO 4 0.08%, EDTA 0.2% KH 2 PO 4 0.2% initial pH 7.0, the medium volume 20mL/250mL, fermentation temperature of 30 ° C. Optimized fermentation supernatant β-glucosidase activity was 52.18 U / mL, the enzyme activity of 3.1 times for the initial fermentation conditions. Found in the study of the enzymatic properties of beta-glucosidase: the enzyme reaction optimum pH of 5.0, the optimum reaction temperature of 70 ° C. Metal ions of Ag have a strong inhibitory effect on the enzyme reaction, Mn 2 , Al 3 on the enzyme has a significant activating effect, Fe 2 , Fe 3 , Cu 2 , Ca 2 , Zn 2 , Co 2 , Ni 2 , Mg 2 , K obvious impact on the enzyme activity. The influence of organic solvents: ethanol (10%), methanol (10%), n-butanol (10% -40%), ethyl acetate (10% -20%), acetone (10%) of the enzyme reaction has role more or less, but high concentrations have a strong inhibitory effect. Enzyme Stability Study Results: The enzyme in a 70 ° C high temperature T1 / 2 up to 20h; pH2.2-8.0 Na2HPO4-citric acid buffer solution can be stored for more than 12h, the enzyme activity is substantially constant. Obtained using degenerate primers reverse transcription in the study of the corresponding gene of the β-glucosidase enzyme in Penicillium, by extracting of Penicillium total RNA, the middle fragment, and a 5 'end fragment is obtained by Genome Walking method, whereby The design at both ends of the amplification primers for full-length, but due to time reasons failed to complete the final step.
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