微波杀菌规律的研究

STUDY ON GERMICIDAL RULE OF MICROWAVE

试验结果表明，在６５０Ｗ微波照射下，杀灭敷料包中枯草杆菌黑色变种芽胞的Ｄ_（１０）值为１．９４分钟。随着微波的功率增大、物品含湿率增高、物品包装密封及与洗必泰协同，均有助于微波的杀菌。枯草杆菌黑色变种芽胞对微波的抗力强于嗜热脂肪杆菌芽胞。

The germicidal rule of microwave in killing some microorganisms under different conditions was observed in laboratory.The results indicated that by exposure to 650 W(2450MHz) microwave radiation,the D10 value for killing spores of Bacillus subtilis var. niger in dressing pack(200 g in weight,moisture rate 50%) was 1.94 min. From the changes of D10 value of microwave for killing spores of B. subtilis var. niger under different conditions,it could be seen that the germicidal action of microwave could be potentiated by increasing microwave power(90 W～650 W) and moisture rate(0%～25%. It meant the degree of moistening of the dressing pack by water spray,i.e.the ratio of the amount of water sprayed to the total weight of wet pack),airtightness of the article(sealed in polypropylene bag) and synergism with chlorhexidine.To the contrary,overload of water(the volume of water put in the chamber)in the microwave sterilizer had unfavorable effect on killing bacteria. The bacterial carriers under the surface of upper layer were less easy to be killed than the bacteria on the carrier in the middle layer.This might be due to that the heat produced in the superficial layer was more easy to dissipate.In addition.the D10 values of synergetic action of microwave and chlorhexidine in killing Escherichia coli,Candida albicans,spores of Bacillus stearothermophilus and spores of B.subtilis var.niger were measured to be 0.33,0.34,1.03 and 1.08 min respectively.The resistance of spores of B. subtilis var.niger was higher than that of spores of B.stearothermopilus,indicating that the action of microwave may be similar to that of dry heat.