Enhancing nonspecific enzymatic hydrolysis of chitin to oligosaccharides pretreated by acid and green solvents under simultaneous microwave-radiation.
Enhancing nonspecific enzymatic hydrolysis of chitin to oligosaccharides pretreated by acid and green solvents under simultaneous microwave-radiation.
复制标题
DOI：
10.1016/j.ijbiomac.2022.04.032
复制
发表时间：
2022-04
影响因子：
8.2
通讯作者：
Meng-Yuan Guo;Xunfan Wei;Sicong Chen;Jinhua Xiao;Dawei Huang
中科院分区：
文献类型：
--
作者：
Meng-Yuan Guo;Xunfan Wei;Sicong Chen;Jinhua Xiao;Dawei Huang
未经处理的高度结晶的甲壳素很难降解。本研究采用酸溶胀甲壳素(AC)和超细几丁质(FC)两种溶剂对甲壳素进行前处理，并采用微波加热法强化溶菌酶和胃蛋白酶的非特异性酶解，使酶解率提高了1.31倍以上。甲壳素底物的表征(MV、SEM、XRD)表明，钙溶剂预处理法(FC)比磷酸预处理法(AC)温和但有效。用胃酶同时微波作用5h后，AC的产率最高(37.58 mg/g)，其中N-乙酰氨基葡萄糖的含量为13.76 mg/g，而用溶菌酶比用胃酶能得到更多的甲壳素低聚糖，聚合度为3~4，乙酰化度较低。值得注意的是，只有当微波和酶共同作用(同步策略)时，甲壳素转化为低聚糖的转化率最高，比单独使用微波处理酶和底物的转化率至少高出35.59%。揭示了微波辐射对溶菌酶和甲壳素底物的损伤，并对整个微波加热酶反应体系的工作原理进行了初步探讨。
It is hard to degrade untreated highly crystalline chitin. In this study, two solvents pretreatment chitin (acid swollen chitin (AC), super fine chitin (FC)) and microwave-heating method were used to enhance nonspecific enzymatic hydrolysis (lysozyme and pepsin), which obviously improved the enzymolysis rates by at least 1.31 times. Characterizations of chitin substrates (Mv, SEM, XRD) showed that calcium solvent pretreatment (obtained FC) was milder but effective than phosphoric acid pretreatment (obtained AC). The highest yield of chitin oligosaccharides (37.58 mg/g) were obtained after hydrolyzing AC under five-hour simultaneous microwave radiation by pepsin, among them, the content ofN-acetylglucosamine was 13.76 mg/g. While, more chitin oligosaccharides with DP (degree of polymerization) 3–4 and lower DA (degree of acetylation) were obtained when using lysozyme than pepsin. Significantly, the conversion rate of chitin to oligosaccharides went best only when microwave and enzymes acting together (simultaneous strategy), which were at least 35.59% higher than separately pretreatment enzymes and substrates by microwave. The damages of microwave radiation on lysozyme and chitin substrates were revealed, and the operating principle of the whole enzyme reaction system heated by microwave was preliminatively explored.