乳酸菌基础培养基比较研究  

STUDY ON COMPARISON OF BASIC CULTURE MEDIUM OF LACTIC ACID BACTERIA

作　　者：李志成[1] 严佩峰[1] 李红蕊[1] 李春燕[1] 李博[1] 

机构地区：[1]西北农林科技大学食品科学与工程学院,陕西杨凌712100

出　　处：《食品研究与开发》2007年第11期71-74,共4页Food Research and Development

基　　金：科技部"西部开发"重大项目(2003BA901A19)

摘　　要：研究了脱脂乳中性蛋白酶的最适酶解条件,并以保加利亚乳杆菌和嗜热链球菌为混合发酵菌种,对MRS、脱脂乳和脱脂乳酶解液3种基础培养基进行了比较研究。结果表明:(1)脱脂乳中性蛋白酶的适宜酶解条件为:加酶量5000U/g蛋白质,在pH=7.0,50℃下酶解2h;(2)脱脂乳酶解液是保加利亚乳杆菌和嗜热链球菌混合菌种较好的基础培养基,其冻干发酵剂的质量和数量均优于脱脂乳培养基。以脱脂乳酶解液为基础培养基制备的冻干发酵剂的活菌数达到3.5×1011cfu/g,冻干发酵剂的重量是脱脂乳的1.93倍。The optimum condition of Enzymatic hydrolysis on neutral protease in skimmed milk was studied. Taking mixed Lactobacillus bulyaricus and Streptococcus thermophilus, the fermented and freeze-dried effect of three basic medium MRS, skimmed milk and its enzymatic hydrolysate was researched. The results showed that： （1）The optimum enzymatic hydrolysis condition on neutral protease in skimmed milk was adding 5000 U/g neutral protease enzymatic hydrolyzing two hours at 50 ℃. （2）The better radical medium of mixed Lactobacillus bulyaricus and Streptococcus thermophilus was the enzymatic hydrolysate of skimmed milk, and its quantity and quality of freeze dried cultures are all better than skimmed milk. The viable bacteria counts of freeze-dried cultures came from enzymatic hydrolysate could reach 3.5×10^11cfu/g and its weight was 1.93 times as much as that of skimmed milk.

关 键 词：乳酸菌 基础培养基 脱脂乳 酶解液 活菌数 

分 类 号：TS252[轻工技术与工程—农产品加工及贮藏工程]