几种常用金属对大肠埃希菌杀灭作用观察

采用悬液定量浸泡杀菌试验和电镜技术,在实验室进行了常用金属对细菌的杀灭作用及其作用机理观察。结果,将不同金属置于含菌悬液内浸泡作用不同时间,金属铜对大肠埃希菌作用 30min,平均杀灭率为 97%;金属银和金作用 30min,平均杀灭率分别为 35. 6%和 30. 3%;不锈钢,金属铝、铁和锡等对细菌作用很弱。透射电镜观察发现,经金属铜作用 30min的大肠埃希菌,其细胞壁出现凹凸不平,局部细胞膜有分离现象,细胞质明显减少甚至消失,细胞核质浓缩呈块状。结论,常用金属中以金属铜、银对细菌作用明显,作用后的细胞结构有改变,其他常用金属对细菌作用不明显。

OBSERVATION ON EFFICACY OF SEVERAL METALS IN KILLING ESCHERICHIA COLI

Suspension immersion quantitative germicidal test and electronmicroscopic technique were used to observe the bactericidal efficacy of common metals and their mechanisms in laboratory. Results: When various metals were immersed in the bacterial suspension for different periods of time, the average killing rate of Escherichia coli exposed to metal copper, metal silver and gold for 30 min was 97%, 35.6% and 30.3% respectively. The effects of stainless steel, metal aluminum, iron and tin on bacteria were very weak. Transmission electronmicroscopic observation found that the cell wall of Escherichia coli exposed to metal copper for 30 min showed embossed unevenness and separation of local cell membrane. The cytoplasm decreased obviously even disappeared and the nucleus was pyknotic into a form of clump. Conclusion: Among the common metals, metal copper and silver have obvious effect on bacteria which have changes in cell structure after exposure to these metals. The effects of other common metals on bacteria are not obvious.