西北地区泡菜中乳酸杆菌的生物学特性

Biological Characteristics of Lactic Acid Bacteria from Pickles in Northwest of China

从西北地区采集的泡菜中分离出四株乳酸菌分别是植物乳杆菌(Lactobacillus plantarum)、短乳杆菌(Lactobacillus brevis)、副干酪乳杆菌(Lactobacillus paracasei)和戊糖乳杆菌(Lactobacillus pentose)。37℃MRS液体培养基中静置培养一定时间,分别测定了四种乳酸杆菌的产酸能力、硝酸盐还原性、亚硝酸盐的降解能力、耐酸耐盐能力和生长特性。结果表明:LPL,LPA和LPE培养15h到达稳定期,LBR培养27h到达稳定期;四株乳酸杆菌的总酸含量分别为1.98%,1.97%,2.10%和1.77%,亚硝酸盐降解率依次为0.87%,0.88%,0.93%和0.88%;四株菌的硝酸盐还原性都为阴性,最低耐酸性为pH 5,最高耐盐性为NaCl含量4%。

In this study,four strains of lactic acid bacteria,such as LPL,LBR,LPA and LPE are iso-lated from pickles in northwest of China.The acid production capability,nitrate reducibility,degrad-ability of nitrite,tolerance to salt and acid,and the growth characteristics of four lactic acid bacteria are measured after cultivated in MRS liquid medium at 3 7 ℃.The results indicate that the LPL,LPA and LPE cultivated for 1 5 h to reach the stationary phase,while the LBR cultivated for 2 7 h to reach the stationary phase.The total acid content of the four strains is 1.98%,1.97%,2.10% and 1.77%, and the degradability of nitrite is 0.87%,0.88%,0.93% and 0.88%.The nitrate reducibility of four strains is negative,the lowest tolerance to acid is pH 5,and the highest tolerance to salt is NaCl of 4%.