摘要
多级孔沸石-咪唑框架-8(zeolitic imidazolate framework-8,ZIF-8)材料相较于传统的ZIF-8材料具有更大的孔径,在固定化酶领域展现了较好的应用前景。目前,利用多级孔ZIF-8材料固定米根霉源脂肪酶(Rhizopus oryzae lipase,ROL)的效果仍不清楚。通过调节ZIF-8材料前驱体的初始物质的量比例,制备得到一种无定形ZIF-8(amorphous zeolitic imidazolate framework-8,aZIF-8)材料,基于ZIF-8和aZIF-8材料,采用原位自封装法制备得到固定化脂肪酶ROL@ZIF-8和ROL@aZIF-8。利用红外光谱仪、X-射线衍射仪和扫描电子显微镜等研究了ZIF-8、aZIF-8、ROL@ZIF-8及ROL@aZIF-8的形貌及结构差异,比较了在不同ROL质量浓度条件下制备的ROL@aZIF-8与相同质量浓度ROL的酶活力,考察了ROL和ROL@aZIF-8的酸碱稳定性、温度耐受性、储藏稳定性以及对邻苯二甲酸二丁酯(dibutyl phthalate,DBP)和邻苯二甲酸二异丁酯(diisobutyl phthalate,DIBP)的水解能力。结果表明,aZIF-8材料呈现出包含十字花形、正方形、球形等多种形态的无定形形貌,是一种具有微孔和介孔的多级孔材料。在ROL的质量浓度为4 mg/mL的条件下制备的ROL@aZIF-8呈现最大酶活力,为5.69 U/mg。在相同的ROL质量浓度条件下,aZIF-8材料的疏水性及多级孔特性促使ROL@aZIF-8的酶活力比ROL高。ROL@aZIF-8比ROL具有更好的碱稳定性、温度耐受性、储藏稳定性以及更高的对DBP和DIBP的水解能力。
Hierarchical porous zeolitic imidazolate framework-8(ZIF-8)materials have larger pore sizes compared with conventional ZIF-8 materials,and show better application prospects in the field of immobilized enzymes.At present,the effect of immobilizing Rhizopus oryzae lipase(ROL)using hierarchical porous ZIF-8 material remains unclear.In this study,an amorphous zeolitic imidazolate framework-8(aZIF-8)material was prepared by adjusting the initial molar ratio of the precursor of ZIF-8 material,and the immobilized lipase ROL@ZIF-8 and ROL@aZIF-8 were prepared by in situ self-encapsulation based on the ZIF-8 and aZIF-8 materials,respectively.The morphological and structural differences of ZIF-8,aZIF-8,ROL@ZIF-8 and ROL@aZIF-8 were investigated by using infrared spectroscopy,X-ray diffractometer and scanning electron microscope,etc.The enzyme activities of ROL@aZIF-8 prepared under different ROL mass concentrations were compared with those of the same mass concentration of ROL.The acid-alkali stability,temperature tolerance,storage stability,and hydrolysis ability of ROL and ROL@aZIF-8 against dibutyl phthalate(DBP)and diisobutyl phthalate(DIBP)were investigated.The results showed that the aZIF-8 material presented an amorphous morphology containing various forms such as cruciate flower-like,square,and spherical,and was a hierarchical porous material with micropores and mesopores.ROL@aZIF-8 prepared at ROL mass concentration of 4 mg/mL showed the maximum enzyme activity of 5.69 U/mg.The hydrophobicity and hierarchical porous properties of the aZIF-8 material contributed to the higher enzyme activity of ROL@aZIF-8 than that of ROL at the same mass concentration of ROL.ROL@aZIF-8 showed better alkali stability,temperature tolerance,storage stability,and higher hydrolytic capacity for DBP and DIBP than ROL.
作者
芦瑜涵
张成楠
李秀婷
徐友强
李微微
LU Yuhan;ZHANG Chengnan;LI Xiuting;XU Youqiang;LI Weiwei(School of Food and Health/Beijing Advanced Innovation Center for Food Nutrition and Human Health,Beijing Technology and Business University,Beijing 100048,China;Beijing Engineering and Technology Research Center of Food Additives,Beijing 100048,China)
出处
《食品科学技术学报》
EI
CAS
CSCD
北大核心
2023年第6期39-51,共13页
Journal of Food Science and Technology
基金
国家自然科学基金资助项目(32001638,31830069)。
关键词
脂肪酶
多级孔沸石-咪唑框架-8材料
固定化酶
原位自封装法
形貌
lipase
hierarchical porous zeolitic imidazolate framework-8 material
immobilized enzyme
in situ encapsulation method
morphology
