麦芽糊精
化学
淀粉
水解
糊精
聚合
环糊精
聚合度
核化学
有机化学
色谱法
聚合物
喷雾干燥
作者
Mohammed Altigani Abdalla,Shu-Jiang Tu,Hinawi A.M. Hassanin,Luhua Zheng,Jingjing Chen
标识
DOI:10.1016/j.enzmictec.2021.109847
摘要
• Maltoheptaose (DP7) has been synthesized from soluble starch in a one-pot cascade reaction. • The sequential addition of the enzymes exhibited a higher conversion ratio over simultaneous addition with 5-fold. • The maximum production of DP7 was achieved in 1 h reaction time with 1 U/g Ga CGT and 1 U/g Bs CD in a sequential addition. • The optimal condition converted 30 g/L soluble starch to 5.4 g/L DP7 in 1 h reaction time with a conversion ratio of 16 %. Maltodextrins (dextrins) are glucose chains normally produced by starch hydrolysis. Maltodextrins are characterized by their degree of polymerization (DP), which indicates the average number of glucose units per chain. Maltoheptaose (DP7), also known as amyloheptaose, is one of the maltodextrin mixtures widely used in foods, cosmetics, and pharmaceutical industries. Recently, the enzymatic synthesis of DP7 has attracted considerable attention, owing to its considerable advantages over chemical methods. In this work, we have designed a one-pot cascade reaction bio-synthesis starting from soluble starch to produce a specific degree of polymerization (DP7). The reaction system was catalyzed by cyclodextrin glucotransferase ( Ga CGT) from Gracilibacillus alcaliphilus SK51.001CGTase (transglycosylation/cyclization reaction) and cyclomaltodextrinase ( BsCD ) from Bacillus sphaericus E-244CDase (ring-opening reaction). The one-pot cascade reaction exhibited an optimum temperature of 30 °C and pH 7.0, and the addition of Ca 2+ enhanced the maltoheptaose production. The optimum enzyme units for the one-pot cascade reaction were 80 U/g of Ga CGT and 1 U/g of BsCD . However, the sequential addition of the enzymes exhibited a 5-fold higher conversion rate over simultaneous addition. The one-pot cascade reaction converted 30 g/L of soluble starch to 5.4 g/L of maltoheptaose in 1 h reaction time with a conversion rate of 16 %.
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