培养基用酪蛋白胨的质量研究

Study on Quality of Casein Peptone Used in Culture Medium

目的:考察国内外用于培养基的酪蛋白胨质量状况。方法:抽取目前国内外常用的6家企业(国外3家,编号为A、B、C;国内3家,编号为D、E、F)的14批酪蛋白胨样品,分别采用干燥失重、酸碱度、碱性沉淀和磷酸盐沉淀等理化分析方法,以及耐热菌数、色素生成能力、促生长能力等微生物学方法进行质量评价。结果:6个厂家样品澄明度良好,灭菌前后p H值稳定,个别样品存在磷酸盐沉淀或碱性沉淀阳性反应;国外产品总体微生物控制较好,未检出耐热菌,国内个别样品耐热菌数达390cfu·g^(-1);不同企业产品色素生成能力存在明显差异;6家企业样品促生长能力均大于80%。结论:目前市场酪蛋白胨产品存在质量差异,国内产品批间差异大,国外个别产品在色素生成能力和磷酸盐沉淀或碱性沉淀等我国传统关注项目上也存在一定问题,生产中应根据不同培养基用途进行严格筛选。

Objective： To investigate the quality of casein peptone used in culture medium at home and abroad. Methods： 14 batches of casein peptone samples from 6 domestic and foreign enterprises（3 foreign companies, numbered A, B, C; 3 domestic companies, numbered D, E, F） were sampled to carry out the quality analysis by using physicochemical methods, such as loss on drying, p H, alkaline precipitation and phosphate precipitation and microbiological methods, such as number of heat-resistant bacteria, pigment production ability, and growth promoting ability. Results： The samples from 6 manufacturers had good clarity, stable p H before and after sterilization. Some samples showed positive reaction of phosphate precipitation or alkaline precipitation. The overall microbial control of foreign products was good and no heat-resistant bacteria were detected. The number of heat-resistant bacteria in some domestic samples reached 390 cfu·g^（-1）. There were significant differences in pigment production ability among different companies. The growth ability of the samples from 6 enterprises was greater than 80%. Conclusion： There are differences in the quality of casein peptone products in the market now. There are big differences among batches of domestic products. A few foreign products also have some problems in our traditionally concerned items such as pigment production ability and phosphate or alkaline precipitation. As a result, casein peptone products should be strictly screened according to the different applications of the culture medium.