保加利亚乳杆菌优良菌种的筛选

目的]筛选保加利亚乳杆菌优良菌种。方法]对选出的5株菌（ADR、S-1、SY、TX-B、MS2）在液体MRS中培养时的生长特性、OD值和pH值和对数生长末期的活菌数进行比较,以TX-B活菌数最高,确定TX-B为后续发酵试验的目标菌株,将其与现有的优良的球菌进行优化搭配,组成发酵剂,通过鲜奶发酵试验,选育出可生产优质酸奶的乳酸菌种（株）。结果]TX-B杆菌在42℃的脱脂乳中培养,其生长速率和产酸速率均很快,发酵3 h可凝乳,凝乳时的活菌数和酸度值分别达到7.35×108cfu/m l和94.3°T,发酵10 h,活菌数最高,达1.36×109cfu/m l。TX-B与球菌搭配,通过鲜奶发酵试验及后酸化特性的检测,制得的产品具有酸奶特有的香气,酸甜适宜。结论]TX-B杆菌是制备酸奶的优良菌种。

Screening of Good Lactobacillus Bulgaricus

Objective] The good lactobacillus bulgaricus was screened.Method] The selected 5 strains(ADR,S-1,SY,TX-B,MS2)were compared on their growth characteristics when cultured in liquor MRS,their OD value and pH value,and the living bacteria number of log growth telophase,with the living bacteria number of TX-B being highest.The TX-B was determined as the target strains of subsequent fermentation test to make optimization matching with existing and excellent coccus and composed of starter culture.The lactic acid bacteria that could produce high-quality yoghurt was bred through the fresh milk fermentation test.Result] When TX-B bacillus was cultured in skimmed milk at 42 ℃,its growth radio and acid production radio all were fast.It could solidify the milk after fermentation for 3 h,in this duration the living bacteria number and acidity value reached 7.35×108 cfu/ml and 94.3 °T resp..The living bacteria number was highest and reached 1.36×109 cfu/ml after fermentation for 10h.Through TX-B was collocated with coccus,the produced product had the special aroma of sour milk with suitable acid and sweet through the fresh milk fermentation test and the detection of acidification characteristics at later stage.Conclusion] TX-B bacillus was an excellent strain of making sour milk.