生孢梭菌生长所需最低水分活度研究

目的探讨用不同介质调节培养基的水活度,严格厌氧微生物生孢梭菌生长所需的最低水分活度。方法用氯化钠、蔗糖及甘油调节梭菌增菌培养基的水分活度,取制备好的新鲜菌悬液,用无菌生理盐水稀释成每1 mL含104 cfu的菌悬液。将上述菌液分别加入3种调节好的梭菌增菌培养基水分活度中,取1 mL稀释至适宜的稀释级注平皿倾注哥伦比亚琼脂培养基,待培养基凝固后装入厌氧培养袋,在35℃培养72 h,计数。结果以氯化钠、蔗糖及甘油调节梭菌增菌液的水分活度,生孢梭菌生长所需最低水分活度分别为0.95~0.96,0.95~0.96,0.92,其中甘油的试验结果相对稳定,生孢梭菌生长所需最低水分活度最低。结论该方法可为水分活度测定在我国非无菌制剂微生物控制中的应用和2020年版《中国药典》相关内容的修订提供参考。

Minimum Water Activity Required for the Growth of Clostridium Sporogenes

Objective To explore the minimum water activity required for the growth of strictly anaerobic microorganisms Clostridium sporogenes,where the water activity is regulated by different media.Methods Sodium chloride,sucrose and glycerin were used to regulate the water activity of clostridium culture medium.The prepared fresh bacterial suspension was diluted with sterile normal saline solution to prepare the bacterial suspension containing 104 cfu per 1 mL.The above bacterial suspension was added into three kinds of clostridium culture media,of which the water activity had been well-regulated.The 1 mL solution was diluted to appropriate dilution level and poured into plate,together with Colombian Agar medium.After the medium solidified,it was loaded into anaerobic culture bag,cultured at 35℃for 72 h,and then counted.Results The minimum water activity required by the growth of Clostridium sporogenes was 0.95-0.96,0.95-0.96 and 0.92,r espectively.The glycerol test results were relatively stable,in which the minimum water activity required by the growth of Clostridium sporogenes was the lowest.Conclusion This method can provide data reference for the application of water activity measurement in microbial control of non-sterile preparations in China and the revision of relevant contents of the Chinese Pharmacopoeia(2020 Edition).