海水对固定化乳酸菌生长的影响

为探究固定化乳酸菌对海水中不同因素的耐受性,采用涂布分离计数法测定海水中不同pH值、NaCl浓度、Pb^2+浓度、葡萄糖浓度对固定化乳酸菌生长的影响。结果表明:海水pH值为6.0,德氏乳杆菌、嗜热链球菌、屎肠球菌三种乳酸菌在海水中的活菌率分别为98.0%、117.6%、111.4%;在海水中添加NaCl和醋酸铅溶液均抑制乳酸菌的生长,但屎肠球菌的耐盐性与耐重金属铅的能力均比德式乳杆菌和嗜热链球菌强;乳酸菌生长的最适葡萄糖浓度为20%,过量葡萄糖会抑制其生长。综合比较三种乳酸菌在海水中的生长耐受性,得出屎肠球菌对海水中的pH值、NaCl浓度、Pb^2+浓度及葡萄糖变量的耐受性较强。

Effect of seawater on the growth of fixed lactobacillus

The effects of pH value,NaCl concentration,Pb^2+concentration and glucose concentration on the growth of immobilized lactic acid bacteria were determined by coating separation counting method in order to study the tolerance of immobilized lactic acid bacteria to different factors in seawater.The results showed that the pH of seawater was 6.0,and the living bacteria rates of Lactobacillus delbrueckii,Streptococcus thermophilus and Enterococcus Faecium in seawater were 98.0%,117.6%and 111.4%respectively.The addition of NaCl and lead acetate solution could inhibit the growth of lactobacillus,but the salt tolerance and lead tolerance of Enterococcus Faecium were stronger than those of Lactobacillus delbrueckii,Streptococcus thermophilus.The optimum glucose concentration for the growth of lactic acid bacteria is 20%,and excessive glucose will inhibit the growth of lactic acid bacteria probably.It was concluded that Enterococcus Faecium had strong tolerance to pH,NaCl concentration,Pb^2+concentration and glucose variables by comparing the activities three strains of lactobacillus in seawater.