Peterz M, Norberg P
J Assoc Off Anal Chem. 1983 Nov;66(6):1510-3.
A method is presented for preparing samples of freeze-dried mixtures of microorganisms for proficiency tests and collaborative studies. The samples may include most microorganisms that are found in routine analysis in food laboratories. Transport of samples during 48 h did not decrease the number of microorganisms, nor was the variability among samples significantly affected by transport. The standard deviation of counts after 5 weeks of storage varied from 0.04 (Staphylococcus aureus) to 0.17 (Clostridium perfringens) log unit. Storage of samples for 10 weeks decreased the number of viable organisms by 0.02-0.43 log unit. Variability among samples increased for Providencia alcalifaciens and Bacillus cereus after 10 weeks of storage. No significant increase was found for the other organisms.
本文介绍了一种制备用于能力验证和协作研究的微生物冻干混合物样品的方法。这些样品可能包括食品实验室常规分析中发现的大多数微生物。在48小时内运输样品不会减少微生物数量，运输也不会显著影响样品之间的变异性。储存5周后计数的标准差从0.04（金黄色葡萄球菌）到0.17（产气荚膜梭菌）对数单位不等。样品储存10周会使活菌数量减少0.02 - 0.43对数单位。储存10周后，产碱普罗威登斯菌和蜡样芽孢杆菌样品之间的变异性增加。其他微生物未发现显著增加。
