微波对普通液体培养基灭菌效果的观察

Observation of the effectiveness of microwave sterilization of ordinary liquid medium

目的探索家用微波炉对普通液体培养基的灭菌效果。方法对不同量的液体培养基分别用微波照射不同时间,观察灭菌效果。结果 200～1 400ml液体培养基在2 450MHz,700W的微波照射下得到3种沸点状态,照射到以上沸腾状态时,各液体培养基经培养后均有细菌生长。各组完全沸腾后继续照射7、9、10、15、19、24和35min,可达到完全灭菌效果,培养基室温保存15d仍无细菌生长,经枯草杆菌黑色变种芽胞菌片ATCC9372测试完全符合卫生部规定标准。用金黄葡萄球菌、大肠埃希菌及普通变形杆菌作为质检,其菌落和形态染色特征及生化反应均无明显变化。结论微波具有杀灭细菌作用,可用于液体培养基的灭菌,且营养成分未被破坏,方法安全可靠,操作简单,省工省时。

Objective To explore the effects of sterilization of ordinary liquid medium in a microwave oven.Methods Different amounts of liquid medium were sterilized with microwaves for different times.Results Samples of 200 ml-1400 ml liquid medium were irradiated with microwaves of 2 450 MHz,700 W to reach three boiling points.There was bacterial growth in each sample of boiling liquid medium.After boiling,each sample was irradiated for 7,9,10,15,19,24,and 35 min.After 15 days,there was no bacteria growth in samples kept at room temperature.After testing with strips of spores of a variant of Bacillus subtilis ATCC9372,all samples met health standards.Sample quality was inspected using Staphylococcus aureus,Escherichia coli,and Proteus vulgaris;there were no obvious differences in the colonies,morphological characteristics,and biochemical responses of these test bacteria.Conclusion Microwaves can kill bacteria and can be used to sterilize liquid media without destroying nutrients.This is a safe,reliable,simple,and easy method of sterilization.