基于平板计数的类球红细菌测量方法研究

Study on Measurement Method of Rhodobacter Sphaeroides Based on Plate Counting

类球红细菌是产辅酶Q10的主要微生物之一,定量检测类球红细菌活菌数对优化类球红细菌的发酵条件具有重要意义。通过对接种方式、接种量、培养基种类以及培养温度进行比较研究,对类球红细菌的平板计数法进行优化,并对优化后的平板计数法进行协同实验验证和不确定度分析。平板计数法最终优化结果为:接种方式为涂布法,接种量为50μL,培养基为营养琼脂,培养温度为32℃;该方法重复性和再现性均较好,室内重复性相对标准偏差为6.0%,室间相对标准偏差为16.4%。所优化方法的相对扩展不确定度为9.2%(k=2),适用于类球红细菌定量测量。

Rhodobacter sphaeroides is one of the main microorganisms producing coenzyme Q 10.The quantitation detection is of great significance for optimizing the fermentation conditions of Rhodobacter sphaeroides.In this study,the plate counting method of Rhodobacter sphaeroides was optimized by comparing the inoculation method,the inoculation volume,the type of culture medium,and the culture temperature.Additionally,the optimized method was validated by collaborative experiments and uncertainty was analyzed.The final optimization result of the plate counting method is:the inoculation method is coating method,the inoculation amount is 50μL,the culture medium is Nutrient Agar,and the culture temperature is 32℃.The optimized method possessed a good repeatability and reproducibility,of which the RSD of within-laboratory repeatability is 6.0%,and inter-laboratory RSD is 16.4%.With relative expanded uncertainty of 9.2%(k=2),the optimized method could play an important role in the quantitation of Rhodobacter sphaeroides.