金黄色葡萄球菌便携式计数测试片的研制

为了研制新型便携式计数测试片检测食品中金黄色葡萄球菌,本文通过正交试验对金黄色葡萄球菌测试片中培养基成份进行优化;研究冷水可溶性凝胶的复配比例,以及优化后的表面活性剂对复配凝胶质构特性的影响。结果表明,金黄色葡萄球菌测试片中培养基组分为胰蛋白胨10 g/L,牛肉膏5 g/L,酵母膏1 g/L,甘氨酸12 g/L,氯化锂5 g/L,尿素0.2 g/L,亚碲酸钾10 mg/L,卵黄粉6 g/L,表面活性剂最优添加量为D-甘露醇4 g/L,丙酮酸钠5 g/L;冷水可溶性凝胶复配比例为瓜尔胶:聚丙烯酸钠=7:3;添加优化后的D-甘露醇和丙酮酸钠的复合冷水可溶性凝胶可获得最优的凝胶质构,其硬度和黏性分别为1362.04 g和630.41 g。将本研究的测试片与国标平板计数方法相比,其检测结果相关性良好(R^2=0.995),可达到相同水平的检出限2CFU/m L和灵敏度(100%)。本文研究的金黄色葡萄球菌测试片可应用于食品中金黄色葡萄球菌的定量检测。

Preparation of Portable Counting Card of Staphylococcus aureus

In this paper, in order to develop a new type of portable counting card for the detection of Staphylococcus aureus in foods, optimization of medium composition of S. aureus count card by orthogonal experiment, the compounding ratio of the cold water soluble gel and the effect of the optimized surfactant on the texture properties of the composite gel were studied. The results showed that the medium components of S. aureus count card were tryptone 10 g/L, beef extract 5 g/L, yeast extract 1 g/L, glycine 12 g/L, lithium chloride 5 g/L, urea 0.2 g/L, potassium tellurite 10 mg/L, yolk powder 6 g/L, the optimal concentration of surfactants were D-mannitol 4 g/L, sodium pyruvate 5 g/L, the proportion of cold water soluble gel was guar gum: sodium polyacrylate=7:3. The optimal gel texture was obtained by adding the optimized cold water soluble gel of D-mannitol and pyruvate. The hardness and viscosity of the composite gel were 1362.04 g and 630.41 g respectively. Compared with the national standard plate counting method, the test results of this study have a good correlation (R2=0.995), which can reach the same level of detection limit of 2 CFU/mL and sensitivity (100%). The S. aureus count card studied in this paper can be applied to the quantitative detection of S. aureus in foods.