ATP荧光微生物快检法中不同材质及孔径微孔滤膜细菌截留效果的评价

Evaluation on microporous membrane with different material and aperture through ATP fluorescent rapid detection

在相同的操作条件下考察了直径13 mm的混合纤维素酯膜、聚碳酸酯膜、醋酸纤维素膜、硝酸纤维素膜等4种常用微孔滤膜对细菌的截留能力。以细菌总数含量为10 CFU/m L的水样为待测样品,过滤体积为50m L,过滤测定5次。当孔径为0.22μm时,4种滤膜的平均截留率依次为100%、94%、84%和72%;当孔径为0.45μm时,4种滤膜的平均截留率依次为92%、82%、70%和70%。因此,孔径为0.22μm的混合纤维素酯膜对细菌的截留效果最好。以该滤膜过滤细菌总数含量为42 CFU/m L、20 CFU/m L、10 CFU/m L、4 CFU/m L的水样各50 m L,然后以ATP生物发光法测定膜上细菌,所得ATP荧光值与细菌浓度的线性相关系数R2>0.9,线性相关性较好。结果显示,0.22μm的混合纤维素酯膜能够满足ATP生物发光法对微菌含量样品的富集测定要求。

The bacterial retention performances of mixed cellulose membrane,polycarbonate membrane,cellulose nitrate membranes and cellulose acetate membranes with 13 mm-diameter were investigated under the same conditions. The total plate count of bacteria in the tested sample was 10 CFU / m L. The filtrate volume was 50 m L,and the filtration was repeated 5 times. When the aperture was 0. 22 μm,the average retention rates of four membranes were100%,94%,84% and 72%,respectively. When the aperture was 0. 45 μm,they were 92%,82%,70% and70%,respectively. Therefore,the best membrane to retain bacteria was mixed cellulose membrane with 0. 22 μm aperture. 50 m L samples respectively containing bacteria 42 CFU / m L,20 CFU / m L,10 CFU / m L and 4 CFU / m L were separately filtered through mixed cellulose membrane. The bacteria on the membranes were determined by ATP bioluminescent method. There was a good linear correlation between fluorescent value and the bacteria concentration( R2>0. 9). The experiment results proved that mixed cellulose membrane with 0. 22 μm aperture could meet the requirements about concentration and measurement of low-level bacteria content sample by ATP bioluminescent method.