新疆酸马奶中乳酸菌的乙醇耐受性及蛋白酶性质研究

Study on ethanol tolerance and protease properties of lactic acid bacteria from koumiss in Xinjiang areas

通过对新疆酸马奶中乳酸菌以传统方式分离鉴定后,筛选得到不同种属菌株,并进一步对其乙醇耐受性及蛋白酶活性差别进行研究。结果表明:在分离的21株菌株中,其不同种属的5株菌株在不同浓度乙醇胁迫12 h后,在耐胁迫能力上,由高到低分别为发酵乳杆菌(Lactobacillus fermentum)、戊糖片球菌(Pediococcus pentosaceus)、植物乳杆菌(Lactobacillus plantarum)、屎肠球菌(Enterococcus faecium)、乳酸片球菌(Pediococcus acidilactici),其中最高能够耐受浓度为13%的乙醇胁迫。对蛋白酶水解能力的测定结果表明,菌株均能产生蛋白酶,其中乳酸片球菌(Pediococcus acidilactici)的水解圈直径最大,为13.1 mm,其菌株自溶度为36.4%。菌株的乙醇耐受性与其蛋白酶水解能力间无显著关联性。

The aim of the study was to investigate the ethanol tolerance and the differences of protease activity of different lactic acid bacteria strains, which were isolated and identified traditionally from Xinjiang lounfiss.After different concentrations of ethanol stress for 12 h, the results showed the stress tolerance of 5 different strains from high to low were LactobaciUus fermentum, Pediococcus pentosaceus, Lactobacillus plantarum, Enterococcus faecium, Pediococcus acidilactici among the 21 strains initially isolated ,one of the which could withstand the highest concentration of 13% ethanol stress.We concluded that all strains could produce protease by measuring the proteolytic activity of the protease,it was worth mentioning that the diameter of the hydrolytic ring of Pediococcus acidilactici was the largest, which was 13.1 mm and the self-solubility was 36.4% .Results have also shown that the relationship between ethanol tolerance and protease hydrolysis was not significant.