Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Aalborg, Denmark.
J Appl Microbiol. 2008 Nov;105(5):1310-7. doi: 10.1111/j.1365-2672.2008.03901.x.
To investigate the effect of oxygen limitation, glucose-starvation and temperature on the susceptibility of Escherichia coli towards the quaternary ammonium biocide benzalkonium chloride (BAC).
The effect of BAC on planktonic and sessile cells were investigated using the gfp-tagged E. coli K-12 strain MG1655[pOX38Km]. Increasing temperature from 10 degrees C to 30 degrees C increased the bactericidal effect of BAC for both starved and nonstarved E. coli under aerobic and anaerobic conditions. The lowest minimum bactericidal concentration was observed for cells in anaerobic media at 30 degrees C (30 mg l(-1) BAC). Decreasing cell densities increased the decay rate for BAC-exposed cells for both starved and nonstarved E. coli. Biofilms of E. coli exposed to BAC in anaerobic medium showed a greater percentage of membrane-compromised cells than biofilms grown in aerobic medium. Image analyses of BAC-exposed biofilms showed that membrane-compromised cells were occasionally located in the interior structure of the biofilm microcolonies.
Increasing temperatures and the absence of oxygen, and energy substrates increased the antimicrobial effect of BAC towards E. coli.
The results are relevant for understanding the disinfection efficacy of quaternary ammonium compounds towards planktonic and sessile bacteria.
研究氧限制、葡萄糖饥饿和温度对大肠杆菌对季铵盐杀菌剂苯扎氯铵（BAC）敏感性的影响。
使用 GFP 标记的大肠杆菌 K-12 菌株 MG1655[pOX38Km]，研究了 BAC 对浮游细胞和生物膜细胞的影响。从 10°C 升高到 30°C，在有氧和无氧条件下，饥饿和非饥饿大肠杆菌的 BAC 杀菌效果均增加。在 30°C 下的厌氧培养基中，观察到最低的最小杀菌浓度（30mg l(-1) BAC）。对于饥饿和非饥饿大肠杆菌，降低细胞密度会增加 BAC 暴露细胞的衰减率。在厌氧培养基中暴露于 BAC 的大肠杆菌生物膜比在有氧培养基中生长的生物膜显示出更高比例的膜损伤细胞。对 BAC 暴露生物膜的图像分析表明，偶尔会有膜损伤细胞位于生物膜微菌落的内部结构中。
升高温度和缺乏氧气、能量底物会增加 BAC 对大肠杆菌的抗菌效果。
本研究结果有助于理解季铵化合物对浮游和生物膜细菌的消毒效果。
