应用4-甲基伞形酮-β-D-半乳糖苷快速检测食品中的大肠菌群

Rapid Determination of Coliforms in Foods with 4-Methylumbelliferyl-β-D-galactopyranoside

依据ISO 9308-1:2000有关大肠菌群具有产生β-半乳糖苷酶的特性,研制了4-甲基伞形酮-β-D半乳糖苷,并以此制成4-甲基伞形酮-β-D半乳糖苷肉汤(MUGal肉汤):将MUGal肉汤与SN0169指定的月桂基硫酸盐胰蛋白胨肉汤对比检测13种标准菌株,所得结果完全一致;对比检验48份食物样品,本法检出大肠菌群的阳性率高出标准法47%。从上述标准法未检出而本法判定为阳性的样品培养液中,分离可疑菌,经乳糖发酵、氧化酶和硝酸盐还原试验以及API 20E鉴定,证明95．1%为大肠菌群。实验结果表明,用4-甲基伞形酮-β-D半乳糖苷肉汤检验食品中大肠菌群,快速、简便、准确、可靠,可作为一种任选的标准方法加以应用。

According to the coliforms characteristics of producing β- galactopyranosidase （referring to ISO 9308-1：2000）. The 4-metylunbelliferyl-β-D-galactopyranoside and 4-metylunbelliferyl-β-D-galaetopyranoside broth（MUGal broth） were prepared. The broth was compared with the lactose-bile ferment tube （specified by GB4789.3） and lauryl sulfate typtose broth （specified by SN0169） for the detection of β standard strains. The yield of coliform and other bacteria obtained by the above three media were the same. 48 food samples were detected by the above methods with the positive defection percentage results of MUGal method were 47% higher than standard method. After the cultures of the higher suspected parts were tested again with the lactose fermentation, and oxidase and reducing nitrate test together with the ApI-20E test. The results showed that the coliforms percentage tested are 95.1%. It was proved that the method of detection for coliforms in foods with 4-methylumbelliferyl-β-D-galactopyranoside is sensitive, accurate and rapid, particularly useful for routine monitoring of food sanitation determination.