两种物理方法破碎大肠杆菌比较试验

A Comparison of Two Physical Methods to Break E.coli Germs

采用超声波和反复冻融两种物理方法,对一定浓度的标准致病性大肠杆菌进行破碎率比较试验.结果表明:在试验条件下,超声波破碎法达到97%以上的破碎率所需时间为30～50min,尤其是菌液浓度为每毫升50亿,用φ10变幅杆破碎,30min破碎率可达99.9%.而反复冻融破碎,无论液氮的低温冷冻人为速溶或自溶,还是采取冷冻箱的冻融,达到50%以上的破碎,要耗时数小时,且要经过预冷冻的过程.

Both physical methods ultrasonic wave and repeated freeze-melt were used to break E. coli germs. The results show：it took 30-50 minutes to break the germs in fluid containing 5-10 billion germs/ ml by ultrasonic wave instrument with variable amplitude lever φ6 and when fluid germ concentration was 50 billion/ml it took 30 min. With φ10 instrument for germs to be broken up to 99.9 %. While the method of repeat freeze-melt, hours time and pre-freeze were needed for over 50 % germs could be broken, no matter artificial or self melting.