摘要
自包头市售酸乳酪中分离出一株链球菌ＳＭ５２６，菌体多为长链球状，革兰氏染色阳性，抗酸染色阴性，兼性厌氧生长，最适生长温度为３０℃．无芽孢、荚膜及鞭毛，不运动．可从多种糖类产酸，但不产气．接触酶阴性，精氨酸双水解酶阳性，不液化明胶，还原石蕊牛奶并凝固．ＤＮＡ中Ｇ＋Ｃ为３８．５ｍｏｌ％．经鉴定，ＳＭ５２６菌株为乳酸链球菌（Ｓｔｒｅｐｔｏｃｏｃｃｕｓｌａｃｔｉｓ）．经用牛津杯琼脂扩散法检测ＳＭ５２６菌株发酵液，该菌能产生一种小分子活性肽——乳酸链球菌肽，它能抑制或杀死包括芽孢杆菌属、葡萄球菌属和梭菌属等在内的多种革兰氏阳性菌，但对革兰氏阴性菌、霉菌及酵母无效．以金黄色葡萄球菌（Ｓｔａｐｈｙｌｏｃｏｃｃｕｓａｕｒｅｕｓ）和枯草芽孢杆菌（Ｂａｃｉｌｕｓｓｕｂｔｉｌｉｓ）为指示菌株表明。
One strain of Streptococci,SM526,was isolated from a commercial yoghurt.It is Gram positive,acid fast negative,nonsporing,facultative anaerobic and without flagellium or capsula.The optimum growing temperature is 30℃. Many kinds of carbohydrates can be utilized,but no gas is produced.Gelatin can not be liquefied.Catalase is negative and arginine dihydralase is positive.Litmus milk is reduced and coagulated.G+C content in DNA is 38.5%(Tm).Therefore,according to the references,strain SM526 is identified as Streptococcus lactis.SM526 can produce an antimicrobial peptide,nisin,which has great inhibitory effect on various Gram positive bacteria including Bacillus,Staphylococcus and Clostridium ,but it has no effect upon Gram negative bacteria,fungi or yeasts.Formode of action,nisin revealed a bacteriocidal mode against Staphylococcus aureus and Bacillus subtilis.
出处
《山东大学学报（自然科学版）》
CSCD
1997年第1期113-120,共8页
Journal of Shandong University(Natural Science Edition)
