Enzymatic Properties And Optimization Of Solid Fermentation Conditions Ofβ-glucosidase

Cellulose can be hydrolyzed into monosaccharides in given conditions, monosaccharides can produce other products by fermentation. Cellulose is a very important class of enzymes, is made up of several hydrolytic enzymes. Cellulase is a complex enzyme, which can degrade cellulose to generate glucose Is customary to call it the cellulase. Generally it consists of three components, known as C1, Cx enzyme, glucosidase enzyme. Cx enzyme play a major role in non-crystalline regions of intramolecular,which random hydrolysis β-1,4-glycosidic bonds, break down long chains of cellulose into a lot of small molecular weight cellulose. C1palys a main role in p-1,4-glycosidic linkage at the end of cellulose enzyme, hydrolysis a cellobiose molecule from the the end of the hydrolysis of cellulose molecules. C1enzyme can hydrolysis microcrystalline cellulose. β-glucosidase hydrolysis of the fibers of the short chain oligosaccharides and cellobiose hydrolysis into glucose.β-glucosidase (EC3.2.1.21, β-D-glucoside hydrolase) is a complex enzyme composed by a variety of enzymes, also known as cellobiase of amygdalin enzyme, is one of the main components of cellulose enzyme, which main effect is catalytic hydrolysis β-glycosidase to release β-D-glucose,_a key enzyme to hydr-olysis cellobiose. The level of beta-glucosidase activity will directly affect the level of the entire cellulase system.In this paper, the study of weak links in the cellulose degradation process——β-glucosidase.was researched. A_high-yield strains of the new production of β-glucosidase was screened from the nature of soil, use straw on strain screening and fermentation production, which provide an excellent matrix for the latter compound of cellulose and degradation, optimize the conditions for solid-state fermentation of β-glucosidase, and its enzymatic properties were analyzed. Use this lab to save PG1glucosidase production by solid state fermentation of strains, and solid and liquid fermentation enzyme activity compared. By using a single factor optimization method for PG1solid fermentation conditions strains of the preliminary optimization, The experimental results show that when the gas exploded straw as the main medium for fungal growth and production of β-glucosidase activity can be8.82U/g, straw is the second smallest, and enzyme activity for7.12U/g, wheat bran and not gas explosion straw is not suitable for fungal growth, enzyme activity minimum. Add5g peptone to the culture medium, enzyme activity increased, reaching to8.93U/g, followed by corn pulp and lees, was the worst of ammonium chloride and ammonium sulfate, had no significant effect on the enzyme activity to improve. humidity of70%, the solid-liquid ratio of1:3, inoculum size of30%, the incubation time of6days, the pH value of5.5, add Fe2+and Tween80to the fermentation, β-glucosidase activity can be achieved13.25U/g.In order to further increase the enzyme activity, PG1strain under optimal fermentation conditions for expanding the training, after the end of fermentation, fermentation starter is soluble in sodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution by crude enzyme solution, Study on enzymatic method, rate it with ammonium sulfate precipitation and enzyme analysis of the dialysis bag of salt after the sinking, and Sephadex-G100DEAE-Sepharose ion exchange column chromatography chromatography column for further purification, purification of the enzyme solution after using SDS-Page to determine its molecular weight, molecular weight of60.1KDa. In order to further improve the activity of β-glucosidase, this experiment on the optimum reaction of β-glucosidase optimum reaction temperature, thermal stability, pH value, pH stability, substrate specificity, add variety and concentration of metal ions and organic solvent effects on enzyme system for exploration, The experimental results show that this β-glucosidase enzyme optimum temperature was50℃; at40℃,50℃,60℃have better stability, less stable in more than80℃; optimum pH value of5;pH=4,5,6, good stability, the stability of the worst pH=3,7,8,9; The optimum of this enzyme substrate is cellobiose, cellobiose and filter paper as substrate, the relative activity higher,101%and105%, which cellobiose as substrate, enzyme activity is the higest, the causes was relate to β-glucosidase catalytic properties glucose and starch as the substrate, the enzyme activity was lower, Among them, glucose was the lowest, the relative activity of only25%. Add Fe2+to enzyme system for activation of enzyme activity of the strongest relative enzyme activities up to121%, Fe2+concentration is greater than6mmol/L, the relative activity decreased with the increase of the concentration of Fe2+, Fe2+concentration of10mmol/L, the relative activity dropped to40%, the activity is basically lost followed byK+and Mg2+, enzyme activity were112.8%and106.2%respectively. With the rise of Fe2+, enzyme activity growing, Concentration of Fe2+of2-4mmol/L, β-glucosidase activity in the highest, relative enzyme activities of134.2%. Ag+. Al3+、Zn2+、Ba2+、Mn2+on the inhibition of β-glucosidase a certain, Ag+is the strongest inhibition, enzyme activity only as18.2%.5%～15%ethanol has a strong activating effect on enzyme activity and relative enzyme activities up to a maximum of120%, with the increase of ethanol concentration, relative enzyme activities gradually reduced, Ethyl acetate and methanol to the enzyme inhibition strong reaction system, along with the increase of conce-ntration, the more obvious inhibition.5%～10%propanol activation of the enzyme has a certain role and relative enzyme activities up to105%, but as the concentration increases, some restraint. Low concentrations of glycerol on the activity activation, but the effect is less marked, increase concentration, inhibition was significantly enhanced.