费氏丙酸杆菌两个亚种的分离与鉴定

用亨格特（Hungate）厌氧技术从不同奶制品分离出3株丙酸杆菌Propionibacterium，编号为PTC－1，PTC－2和PTC－3。细胞呈多形态，杆状，革兰氏阳性，不形成芽孢，不运动，菌落在PYG深层洋菜中呈双凸透镜状，白至土黄色，从葡萄糖、乳糖等8种碳水化合物发酵产酸，葡萄糖发酵产物包括大量丙酸和乙酸，少量异丁酸，琥珀酸和CO₂。厌氧至耐氧。PTC－1的DNA的GC百分含量测定值为67.8mol％（Tm）。三株菌的特性很接近，只在硝酸盐还原和牛奶凝固特性有差

ISOLATION AND IDENTIFICATION OF TWO SUBSPECIES OF PROPIONIBACTERIUM FREUDENREICHII

Three strains Propionibacterium (PTC-1, PTC-2 and PTC-3) were isolated fromdifferent dairy products by using Hungate anaerobic technology. Cells are pleomorphic rods,Gram-positive, non-sporing, nonmotile. Colonies in PYG deep agar of roll tubes are lenticular,white, yellow to ho. Acids are produced from eight kinds of carbohydrates e. g. glucose,lactose and so on. Fermentation products of glucose include large amounts of propionic andacetic acid, and lesser amounts of isobutyric, succinic acids and carbon dioxide. They areanaerobic to aerotolerant. G C content of the DNA of PTC-1 is 67.8 mol% (Tm). Thecharacters of three strains are close, a little different lie in the natures of nitrate areduce andmilk curd. They all were determined as; PTC-1 and PTC-2 are identical species, Propionibacterium freudenreichii subsp. freudenreichii (AS 1.2128 and AS 1.2129 respectively), PTC-3 isP.freudenreichii subsp. shermanii (AS 1.2130). They are important strains in the use of thefermentation and food industries in group of classical propionibacteria.