牛乳中嗜冷菌数与胞外蛋白酶活性相关性的研究  

Study on relativity of psychrotrophic bacteria count and extracellular proteinase activity in raw milk

作　　者：王辉[1] 吕加平[1] 迟玉杰[2] 

机构地区：[1]中国农科院农产品加工研究所,北京100094 [2]东北农业大学食品学院,黑龙江哈尔滨150030

出　　处：《食品工业科技》2008年第2期84-86,89,共4页Science and Technology of Food Industry

基　　金：国家科研院所社会公益项目(2002005DIA4G035-7)

摘　　要：主要研究了牛乳中嗜冷菌数与其产生的耐热性胞外蛋白酶活性的相关性。从原料乳中分离出一株优势嗜冷菌,实验室初步鉴定后用API20NE系统进行鉴定,鉴定该菌为荧光假单胞菌(Pseudomonas Fluorescens),产酶实验结果表明,该菌产耐热性胞外蛋白酶。利用该菌株研究牛乳中单一嗜冷菌菌数与蛋白酶活性的关系,结果表明菌数与蛋白酶活性呈一定正相关,回归方程为Y=0.4548ln(X)+0.4178,决定系数R2=0.8172,相关系数R=0.9039,差异极显著(P<0.01);自然状态下,原料乳中嗜冷菌数与蛋白酶活性关系实验结果表明,原料乳在不同条件下贮存,嗜冷菌数有明显的增加趋势,但原料奶中嗜冷菌数和蛋白酶活性之间没有多少相关性。Pseudomonas Fluorescens,a raw milk isolate and producingheat resistant extracellular proteinase, was identified by AP120NE. It was used to study relativity of psychrotrophic bacteria count and extracellular proteinase activity in raw milk. Least squares analyses showed that the count of single psychrotrophic bacteria were positively related （ R = 0.9039） to proteinase activity（ p 〈 0.01 ）, regression equation was Y = 0.45481n （×） ＋ 0.4178. The other result showed, in nature, however, psychrotrophic bacteria count in raw milk increased significantly with temperature and time, there had no better relative coefficient between psychrotrophic bacteria count and proteinase activity.

关 键 词：牛乳 嗜冷菌 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]