Method Bifidobacterium plasmid was extracted by mutanolysin from Streptomyces globisporus which could lyse the wall of bifidobacterium.The result was compared with that by lysozyme.

方法利用球孢链霉菌发酵产生的变菌素消双歧杆菌细胞壁，提取质粒，并与商业菌酶法比较。