摘要 为了探究固定化中性脲酶用于黄酒中尿素降解的可行性,首先对游离中性脲酶的酶学性质进行了测定,并与酸性脲酶进行比较,分析其用于处理黄酒中尿素的潜力;然后以壳聚糖为载体采用共价结合法进行中性脲酶的固定化,将固定化中性脲酶用于黄酒中尿素的降解。结果表明,游离中性脲酶在酸性条件(pH 4.0)下只能保留极低的酶活力,较高的酒精体积分数(24%)对其酶活力的影响不大。经过固定化,中性脲酶的最适pH由7.0降低到5.0,耐酸性也有显著提高。与游离酶相比,温度和酒精对于固定化酶活性和稳定性的影响没有显著改变。将此固定化中性脲酶处理黄酒,在30℃,加酶量为1000 U/L的条件下处理24 h,可减除黄酒中95%以上的尿素。重复利用固定化酶处理黄酒也有一定的效果。该研究结果为今后固定化中性脲酶用于黄酒中尿素的降解提供了一定依据。 In order to explore the feasibility of immobilized neutral urease for the degradation of urea in Huangjiu(Chinese rice wine),the enzymatic properties of free neutral urease were measured and compared with that of the acid urease.The covalent bonding method was used to immobilize neutral urease with chitosan,and the immobilized neutral urease was used for the degradation of urea in Huangjiu.The results showed that the free neutral urease retained very low enzyme activity under acidic conditions(pH=4.0),while high ethanol volume fraction(24%)had little effect on its activity.After immobilization,the optimal pH of neutral urease was lowered down from 7.0 to 5.0,and acid resistance was also significantly improved.Compared with the free enzyme,temperature and alcohol had little effect on the activity and stability of the immobilized enzyme.This immobilized neutral urease was used to treat Huangjiu at 30℃with dosage of 1000 U/L for 24 hours,which could degrade more than 95%of urea in Huangjiu.Reusing immobilized enzymes also had a certain effect on the treatment of Huangjiu.This study provides a basis for the future application of immobilized neutral urease for the degradation of urea in Huangjiu.
出处 《食品与发酵工业》 CAS CSCD 北大核心 2021年第9期70-75,共6页 Food and Fermentation Industries
基金 国家重点研发计划项目(2018YFC1604106) 国家轻工技术与工程一流学科自主课题(LITE2018-12) 江苏高校品牌专业建设工程资助项目(TAPP)。
