一株优良乳酸菌的分离鉴定与特性研究

利用乳酸菌分离专用培养基-MRS培养基从发酵40 d的酸菜汁中分离得到一株乳酸菌，利用经典分类法对所分离的乳酸菌菌株进行了系统的细菌学鉴定和生物学特性研究。结果该菌株被鉴定为乳杆菌属、植物乳杆菌。对其进行生长曲线、pH及酸度的测定，结果显示分离乳酸菌的对数生长期较长；培养以后pH下降达到稳定；酸度较高的产酸时间为前20 h。抑菌试验表明：该菌株对大肠杆菌、金黄色葡萄球菌均有明显抑制作用。由于该菌具有生长快、产酸量高并具有抑菌活性等特点，因而适合作为微生态制剂的优良菌种开发利用。

Identification and Characteristic Study of an Excellent Lactic Acid Bacterium

A strain of lactic acid bacterium was obtained from the sample of 40th day natural Fermentation sauerkraut with MRS medium which was special for isolation of lactic acid bacterium.Systematic identification by classical methods showed that the isolated strain was belong to genus of Lactobacillus,Lactobacillus planetarium.Biological characteristic research including measuring growth curve,pH value and acidity of the lactic acid bacterium showed the results that the logarithmic growing peak was 16th hour,the pH value reached at stable levels after decreasing for 20 hours and the high acidity acid-producing series was 20 hours.The results of bacteria inhibition experiment showed that the separated lactic acid bacterium had remarkable bacteriostasis on the growth of E coli and staphylococcus.As the bacterium had the characters of rapid growth,high acid-production and bacteriostasis,then we can develop the superior bacterium as micro ecological preparation.