不同方法保存的菌种对次氯酸钠敏感性的比较

为比较实验室不同方法保存的大肠杆菌对次氯酸钠的敏感性,进行了悬液定量杀菌试验。结果,保存前的大肠杆菌,用含有效氯25mg/L的溶液作用15min,杀灭率≥99.90％;经4℃半固体培养基保存至9个月或-20℃肉汤甘油保存至18个月的大肠杆菌,用含有效氯25mg/L的溶液作用10min,杀灭率即≥99.90％;以-150℃肉汤甘油保存的大肠杆菌,至21个月才较易杀灭。说明4℃保存的大肠杆菌宜在半年内使用。

COMPARATIVE SUSCEPTIBILITY OF TYPE CULTURE PRESERVED BY DIFFERENT METHODS TO SODIUMHYPOCHLORITE

In order to compare the susceptibility of Escherichia coli preserved by different methods in laboratory to sodium hypochlorite, quantitative suspension germicidal test was carried out. The results showed that before preserving the killing rate of Escherichia coli exposed to the solution containing available chlorine 25 mg/L for 15 min was ≥99.90%. After being preserved in 4℃ semisolid culture medium for 9 months or in -20℃ broth-glycerin for 18 months, the killing rate of Escherichia coli exposed to the solution containing available chlorine 25 mg/ L for 10 min was ≥99.90%. Escherichia coli preserved in -150℃ broth-glycerin was easy to be killed only after being preserved for 21 months. The above results indicate that Escherichia coli preserved at 4℃ should be used within half a year.