大肠菌群测定初发酵培养基的改进

用我国国家标准乳糖胆盐培养基(GB4789.3-94,简称GB)、日本卫生协会煌绿乳糖胆盐肉汤培养基(简称BGLB)和美国食品与药品管理局(FoodandDrugAdministration,简称FDA)月桂基硫酸盐胰蛋白胨肉汤培养基(简称LST)对大肠杆菌菌液以及蔬菜中的大肠菌群进行检测对比试验。结果表明:LST培养基对大肠菌群的检出率比BGLB培养基和GB培养基分别高35.93%、67.71%。以LST培养基为基础并优选出A3培养基(LST+0.2%吐温),扩大实验表明:A3培养基对大肠菌群的检出率比GB培养基和LST培养基分别高出577.12%和143.72%。

An Improved Medium for the Detection of Coliform Groups

The comparison of three initial fermenting media, i.e. GB medium ( GB4789.3- 94) , BGLB medium of JPHA and LST medium of FDA, which were used in the coliform groups detection at present, was done in the article. After the experiments of detecting the coliform groups in vegetables and suspension of Escherichia coli, it was believed that LST medium was the best one among the three. Determining LST medium as the basic one, SDS and Tween of dif- ferent concentrations were added. The result revealed that A3 medium ( LST+0.2% Tween) could improve the activity of G+ and G- bacteria and promote the bacteria dispersing. The successful rate of A3 medium in detecting coliform groups of 12 specimens was higher than GB medium and LST medium by 577.12% and 143.72% respectively.