| Cyclodextrins (CyDs)'s hydrophobic cavity and hydrophilic outer tube-like structure can embed many substances or odor,and CyDs are widely applied in drug field,food industry,agriculture,cosmetic. As a member of CyDs, Degree of polymerization that is more than 9,the large-ring cyclodextrins (LR-CDs) attracted more attention for the property of high water-solubility, low viscosity, revitalization and innocuity, especially the no confinement in food industry. It became alternatives of many plant gum and sodium alginate, and widely used in various fields and become more and more domestic and foreign research scholars concerned object.The production and preparation of a large-ring cyclodextrins has become a hot research. Especially,Acting upon starch, amylomaltases can produce cycloamylose or a thermoreversible starch gel, both of which are commercial interest. Amylomaltase from Thermus aquaticus (Taq) is particularly highly suitable for the production of cycloamylose on an industrial scale. Taq amylomaltase can catalyze the disproportionation, cyclization, hydrolysis and coupling reactions on starch, produce cycloamylose with larger (LR-CDs). However, due to the production of large cyclodextrins, purification processes are very complex, low yield and high cost, So we turn in the recombinant maltose enzyme glucose-based fermentation process based on research by a large ring to improve paste Sperm production, and promote the industrial production of large cyclodextrinsIn this study, the fermentation condition of the recombinant thermophilic amylomaltase engineering strain were optimized, the method of breaking cytoderm and analyzing Amylomaltase activity were also researched.In order to transfer recombinant maltose enzyme glucose-based optimal level of enzyme production capacity, based on the original medium by single factor analysis of the recombinant enzyme maltose switch to glucose-based genetic engineering bacteria for the best fermentation medium:2.5% molasses, tryptone 1.5%, MgSO4·7H2O:K2HPO4 1:7, in the single-factor analysis of the response surface method based on the analysis of the recombinant enzyme maltose switch to glucose-based genetic engineering bacteria the best medium for fermentation to determine the reorganization of the large intestine Bacillus best medium composition (%, W/ V) as follows:molasses 2.65, peptone 1.35, MgSO4·7H2O:K2HPO4·3H2O=7.15:1. According to the above optimum conditions for validation experiments, the recombinant maltose transfer activity of the enzyme glucose-based to 760.582U/mLBased on the best medium of transfected recombinant maltose enzyme glucose-based fermentation conditions were optimized by the transfer of glucose-based recombinant enzyme maltose optimum fermentation conditions were:liquid volume was 100 mL/250mL, speed 200 r / min,5% inoculum, initial pH 7.0, optimum temperature was 37℃, induction phase OD600= 0.6, induced by temperature is 35℃, induction time of 5 h, inducer concentration 1 mmol/L. After optimization, re-transfer glucosyl maltose enzyme activity up to 950U/mL, the initial conditions than the nearly 7-fold increase,Transfer of recombinant maltose by the enzyme glucose-based genetic engineering bacteria 5L fermentor conditions were studied to determine the optimal culture conditions for fermentation as follows:fermentation tank's speed constant 300r/min, ventilation 1.5L/min, the beginning of the culture temperature is 35℃, after 8h the induction phase of culture temperature is 37℃, the tank's pH, acid-base tandem fed by bottle to automatically control the pH=7.0 about 40% dissolved oxygen control tank, after 8h fermentation constant flow of molasses added to 7% of the carbon fed to the fermentation liquid, so that the switch to glucose-based recombinant maltose enzyme activity was 1530U/mL... |
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