微小毛霉凝乳酶的制备工艺  

Preliminary Research on Preparing Procedure of Milk-clotting Enzyme from Mucor pusillus

作　　者：郑恒光[1] 陈君琛[1] 汤葆莎[1] 吴俐[1] 

机构地区：[1]福建省农业科学院农业工程技术研究所,福建福州350003

出　　处：《福建农业学报》2011年第5期847-851,共5页Fujian Journal of Agricultural Sciences

基　　金：福建省科技计划项目--省属公益类科研院所基本科研专项(2010R1017-1);福建省财政专项--福建省农业科学院创新团队建设项目(STIF-Y05)

摘　　要：以食用菌菌糠和豆渣1∶1(w/w)混合物作为微小毛霉固体发酵培养基,探讨微小毛霉凝乳酶粉末制剂的制备工艺。制备过程包括:三角瓶固体发酵、加水提取、Al2(SO4)3絮凝、微滤除菌、超滤浓缩、室温醇沉、40℃真空干燥等7个步骤。结果显示:凝乳酶在水溶液中的热变性为52℃左右,而在70%含水酒精中的变性温度则降至35℃左右。酶液酒精浓度达到70%时对凝乳酶醇沉效果最好,其酶活回收率可达77.24%。本试验最终得到纯度为65.8%的粗酶粉末制剂,酶分离过程的回收率为69.1%,单位质量的培养基转化成凝乳酶粗酶的效率为4 975SU.g-1。研究还表明,与常规制备工艺所采用的低温醇析和真空冷冻干燥的苛刻条件相比,在室温醇析和40℃真空干燥等相对简陋条件下制备微小毛霉凝乳酶,仍可获得较高的酶活回收率。In this research,dried soymilk residue and spent culture substrate of Flammlina velutip were mixed at the ratio of 1∶1（w/w） as the culture medium for Mucor pusillus to generate milk-clotting enzyme（rennet）.The process of preparing crude milk-clotting enzyme powder was investigated.The procedure was divided in 7 steps including solid-state fermentation in Erlemeyer flask,water extraction,flocculation with Al2（SO4）3,microfiltration to remove fungi,ultrafiltration to concentrate enzyme,ethanol precipitation under room temperature,vacuum drying at 40℃.Results showed that the temperature for inactivation of rennet was around 52℃ in water solution,while lowered it to 35℃ in ethanol solution.The ethanol concentration for the best effect in rennet precipitation was 70%,which recovered rennet activity of 77.24%.The final product obtained was in crude enzyme powder with its purity in rennet for 65.8% and the recovering efficiency of filtrated enzyme for 69.1%.The biotransformation of rennet in crude enzyme was 4 975 SU per gram of culture medium.Comparing conventional procedure in low-temperature precipitation and freeze-drying,results indicated that the milk-clotting enzyme of Mucor pusillus could be recovered in certain extent of rennet activity even with room-temperature precipitation and 40℃ vacuum drying.

关 键 词：菌糠 微小毛霉 凝乳酶 酶制剂 

分 类 号：TS20[轻工技术与工程—食品科学]