Different enzymatic conditions and methods for producing maltoheptaose
學生姓名:
邱琬軒
指導教授:
方翠筠
學期:
112下
摘 要:
Maltoheptaose is a maltooligosaccharide containing seven glucose units, characterized by lower osmotic pressure, higher viscosity, better moisturizing effect, and more robust film forming properties, it has been widely used in fields such as food, medicine and cosmetics
industries.Cyclomaltodextrinase (CDase) is an enzyme, which hydrolyzes cyclodextrins (CDs) efficiently. Using CDs as a substrate, maltodextrin is formed via CDase and subsequently hydrolyzed to prepare maltose heptasaccharide. Therefore, this study aims to explore the
characteristics and synergetic mechanism between enzymes for the preparation of maltoheptaose. The cyclodextrin glucotransferase (GaCGT) from Gracilibacillus alcaliphilus and cyclomaltodextrinase (BsCD) from Bacillus sphaericus catalyzed the one-pot cascade reaction to produce maltoheptaose, the results showed that the optimal conditions were at pH 7.0 and temperature 30°C, in the presence of Ca2+ . Furthermore, the optimum enzyme units for the reaction were 80 U/g of GaCGT and 1 U/g of BsCD, and sequential addition of the enzymes exhibited a 5-fold higher conversion rate over simultaneous addition. On the other hand, cyclodextrinase (CDase) from Bacillus sphaericus E-244 and maltooligosyltrehalose synthase (MTSase) from Arthrobacter sp. Q36 exhibits optimal conditions at pH 7.0 and 40°C for one27 pot synthesis of nonreducing maltoheptaose (N-G7). Simultaneously adding CDase and MTSase at 40°C for 4 hours have maximum yield of N-G7 at 77.3%, the conversion efficiency of the sequential treatment is lower than that of the simultaneous method, which further proves that the simultaneous reaction of the two enzymes contributes to the improvement of conversion efficiency. In summary, the method of dual-enzyme cascade reaction treatment has great potential for synthesizing N-G7 and application in the food industry.
industries.Cyclomaltodextrinase (CDase) is an enzyme, which hydrolyzes cyclodextrins (CDs) efficiently. Using CDs as a substrate, maltodextrin is formed via CDase and subsequently hydrolyzed to prepare maltose heptasaccharide. Therefore, this study aims to explore the
characteristics and synergetic mechanism between enzymes for the preparation of maltoheptaose. The cyclodextrin glucotransferase (GaCGT) from Gracilibacillus alcaliphilus and cyclomaltodextrinase (BsCD) from Bacillus sphaericus catalyzed the one-pot cascade reaction to produce maltoheptaose, the results showed that the optimal conditions were at pH 7.0 and temperature 30°C, in the presence of Ca2+ . Furthermore, the optimum enzyme units for the reaction were 80 U/g of GaCGT and 1 U/g of BsCD, and sequential addition of the enzymes exhibited a 5-fold higher conversion rate over simultaneous addition. On the other hand, cyclodextrinase (CDase) from Bacillus sphaericus E-244 and maltooligosyltrehalose synthase (MTSase) from Arthrobacter sp. Q36 exhibits optimal conditions at pH 7.0 and 40°C for one27 pot synthesis of nonreducing maltoheptaose (N-G7). Simultaneously adding CDase and MTSase at 40°C for 4 hours have maximum yield of N-G7 at 77.3%, the conversion efficiency of the sequential treatment is lower than that of the simultaneous method, which further proves that the simultaneous reaction of the two enzymes contributes to the improvement of conversion efficiency. In summary, the method of dual-enzyme cascade reaction treatment has great potential for synthesizing N-G7 and application in the food industry.
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