一株乳酸菌培养条件优化及菌种鉴定

针对取自某工厂的一株未知乳酸菌种进行菌株的培养条件优化及菌种鉴定。以乳酸菌在不同固体培养基中的菌落数、菌落大小及溶钙圈大小为检测指标确定乳酸菌分离培养基为最优乳酸菌固体培养基。在此基础上,对其固体和半固体形式中的生长情况进行比较,发现半固体培养较固体培养更适于乳酸菌生长。通过对乳酸菌生长曲线、pH-t曲线的绘制,了解了此种乳酸菌的生长特性。通过菌落形态观察以及生化鉴定实验,如：吲哚试验、接触酶试验、运动性检测、糖发酵试验等鉴定出此种乳酸菌为德氏乳杆菌保加利亚亚种。

Optimization of culture conditions and strain identification of a lactic acid bacterium

This paper is unknown a lactic acid bacterium optimization of culture conditions and the identification which is from a factory. Detection of standards are the quantity of the colonies, the colony size, dissolved calcium circle of lactic acid bacterium in different solid mediums which make sure that lactic acid bacterium separation medium is the best solid medium. On this basis, we compa~d semi-solid culture to solid culture that semi-solid culture is more suitable than solid cuhure for the growth of lactic acid bacterium. We drew the lactic acid bacterium growth curve, pH-t curve. We understand this kind of lactic acid bacterium growth trait. This lactic acid bacterium is identified as Lactobacillus delbmeckii ssp.bulgaricus through colony morphology observation and identification of biochemical experiments such as indole test, contact enzyme test, detection of strains campaign, sugar fermentation test.