离子液体辅助纤维素酶Tma Cel5A降解黄原胶的性能  

Degradation of xanthan by ionic liquid assisted cellulase Tma Cel5A

作　　者：陈春树 李宪臻[1] 杨帆[1] CHEN Chunshu;LI Xianzhen;YANG Fan(School of Biological Engineering,Dalian Polytechnic University,Dalian 116034,China)

机构地区：[1]大连工业大学生物工程学院,辽宁大连116034

出　　处：《大连工业大学学报》2023年第5期334-338,共5页Journal of Dalian Polytechnic University

基　　金：辽宁省自然科学基金项目(J2020041).

摘　　要：黄原胶因其致密的结构导致酶法的降解效率很低,离子液体能够打开多糖的致密结构而使其处于无序松散的状态,为确定离子液体能够辅助酶更好地降解黄原胶,将来源于Thermatoga maritima的纤维素内切酶Tma Cel5A的基因序列Cel5 A进行全基因合成同时对密码子进行了优化,合成产物pET-Cel5A于大肠杆菌中表达。编码基因Cel5 A长度为951 bp,纤维素内切酶Tma Cel5A理论分子质量为37 ku。SDS-PAGE结果表明该酶为可溶性表达。酶学性质结果显示该酶最适温度为45℃,最适pH为5.0。以黄原胶作为底物测定Tma Cel5A对离子液体的耐受性,结果表明Tma Cel5A对[Bmim]Cl、[Emim]OCOOH、[Emim]DEP均有一定的耐受性。离子色谱及红外光谱对寡糖检测结果表明,低剂量的离子液体能够辅助Tma Cel5A降解黄原胶生成更多寡糖。实验证实离子液体能够辅助酶法高效降解黄原胶制备黄原胶寡糖。Xanthan has a dense structure that results in low degradation efficiency by enzymatic methods.Ionic liquids can open the dense structure of polysaccharides and place them in a disordered and loose state.To confirm that ionic liquids can assist enzymes to degrade xanthan,the gene sequence of the cellulose Tma Cel5A from Thermotoga maritima was fully synthesized and the codon was optimized.The synthetic product pET-Cel5A was expressed in E.coli.The coding gene Cel5A is 951 bp in length,and the theoretical molecular weight is 37 ku.SDS-PAGE result showed that the enzyme was expressed as a soluble protein.The results of enzymatic properties showed that the optimal temperature and pH of the enzyme were 45℃and 5.0,respectively.The tolerance of Tma Cel5A to ionic liquids was determined using xanthan as a substrate.The results showed that Tma Cel5A had a certain tolerance to[Bmim]Cl,[Emim]OCOOH,and[Emim]DEP.The detection results of oligosaccharides by ions chromatography and infrared spectroscopy showed that low doses of ionic liquids could assist Tma Cel5A in degrading xanthan to produce more oligosaccharides.The experiments confirmed that ionic liquids can assist enzymatic degradation of xanthan to prepare xanthan oligosaccharides with high efficiency.

关 键 词：黄原胶寡糖 离子液体 纤维素内切酶 

分 类 号：Q816[生物学—生物工程]