温度对原料乳中分离的耐冷菌产胞外酶的影响  

Effect of temperature on extracellular enzymes produced by psychrophilic bacteria isolated from raw milk

作　　者：夏永军[1] 张峰[1] 宋馨[1] 王光强[1] 艾连中[1] 熊智强[1] XIA Yongjun;ZHANG Feng;SONG Xin;WANG Guangqiang;AI Lianzhong;XIONG Zhiqiang(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093)

机构地区：[1]上海理工大学健康科学与工程学院,上海食品微生物工程技术研究中心,上海200093

出　　处：《工业微生物》2022年第4期1-5,共5页Industrial Microbiology

基　　金：国家重点研发计划项目(2018YFC1604305);上海食品微生物工程技术研究中心(19DZ2281100)。

摘　　要：耐冷菌在原料乳低温贮藏、加工和运输等过程中广泛存在,通过产生耐热蛋白酶和脂肪酶等胞外酶,水解牛奶中的乳清蛋白、牛血清白蛋白、酪蛋白和甘油三脂,导致乳制品品质显著下降。本文从原料乳中分离出29株假单胞菌和1株芽孢杆菌,90℃处理5 min使耐冷菌Z8、Z14、P4、P5和P8胞外脂肪酶活性分别提高1.88倍、2.20倍、2.00倍、2.25倍和3.67倍,使菌株P11、P15和Z7胞外蛋白酶活性分别提高1.89倍、1.81倍和2.11倍,表明耐冷菌能够分泌耐热胞外酶。培养温度对耐冷菌产胞外酶有显著影响,4℃和37℃培养能够抑制耐冷菌产酶能力。本研究为原料乳中耐冷菌及其胞外酶的控制提供理论依据。Psychrophilic bacteria are widely found in raw milk during low temperature storage,processing and transportation.Through the production of extracellular enzymes such as heatresistant proteases and lipases,whey protein,bovine serum albumin,casein and triglyceride in milk were hydrolyzed,resulting in a significant decline in the quality of dairy products.In this paper,29 Pseudomonas strains and 1 Bacillus strain were isolated and identified from the raw milk.After the treatment with 90℃for 5 min,the extracellular lipase activities of psychrotrophic bacteria Z8,Z14,P4,P5 and P8 increased by 1.88,2.20,2.00,2.25 and 3.67 times,respectively,and the extracellular protease activity of P11,P15 and Z7 strains increased by 1.89,1.81 and 2.11 times,respectively,indicating that psychrotrophic bacteria could secrete thermostable extracellular enzymes.Culture temperature had a significant effect on the extracellular enzyme produced by thermophilic bacteria,and 4℃and 37℃could inhibit the enzyme production.This study provided a theoretical basis for the control of psychrophilic bacteria and their extracellular enzymes in raw milk.

关 键 词：原料乳 耐冷菌 胞外酶 脂肪酶 蛋白酶 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]