食品中沙门氏菌缓冲蛋白胨水培养基的优化

Optimization of Buffered Peptone Water Medium for Salmonella in Food

目的:优化食品中沙门氏菌缓冲蛋白胨水培养基的配比,缩短检验周期,使食品安全预警时间点前移。方法:通过吸光度法和平板计数法同时测定不同优化条件下缓冲蛋白胨水培养基中沙门氏菌的生长曲线,对结果进行处理分析,确定最优方案,并采用实时荧光PCR法进行菌种验证。结果:吸光度法和平板计数法曲线变化基本一致,随着缓冲蛋白胨水培养基中酵母添加量的增加,沙门氏菌的调整期缩短,对数期斜率和稳定期数值呈增大的趋势。当改良缓冲蛋白胨水中酵母浸膏的添加量为9 g/L时,食品中沙门氏菌的前增菌时间缩短到8~10 h。通过实时荧光PCR法的验证,确定改良缓冲蛋白胨水培养基特异性良好。结论:根据实际情况选择缓冲蛋白胨水培养基中酵母的添加量,优化后的缓冲蛋白胨水培养基检测时间短、特异性强,可用于食品中沙门氏菌的快速检测,为商品化缓冲蛋白胨水培养基的生产提供参考依据。

Objective:By optimizing the ratio of buffered peptone water medium for Salmonella in food,the detection period is shortened and the time point of food safety warning is moved forward.Method:The growth curve of Salmonella in buffered peptone water medium under different optimized conditions was determined by absorbance method and plate counting method simultaneously.The results were processed and analyzed to determine the optimal plan,and the real-time fluorescent PCR method was used to verify the strains.Result:The curve changes of absorbance method and plate counting method were basically the same.With the increase of yeast addition in buffered peptone water medium,the adjustment period of Salmonella was shortened,and the slope of logarithmic phase and the value of stable phase increased.When the addition amount of yeast extract in modified buffered peptone water was 9 g/L,the pre-enrichment time of Salmonella in food was shortened to 8~10 h.The specificity of the modified buffered peptone water medium was confirmed by real-time fluorescence PCR method.Conclusion:The amount of yeast added in the buffered peptone water medium should be selected according to the actual situation.The optimized buffered peptone water medium has a short detection time and strong specificity,and can be used for the rapid detection of Salmonella in food.This study can provide a reference for the production of commercial buffered peptone water medium.