School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR, China.
Water Res. 2012 Sep 1;46(13):3951-7. doi: 10.1016/j.watres.2012.05.033. Epub 2012 May 27.
The roles of bacterial cellular components, namely, fatty acid profile and coenzyme A, in photocatalytic inactivation of bacteria were investigated. Escherichia coli BW25113, as a "parental strain", and its isogenic single-gene deletion mutants E. coli JW1081 (fabF(-) mutant) and E. coli JW3942 (coaA(-) mutant) showed different susceptibilities towards photocatalytic inactivation by titanium dioxide (TiO(2), irradiated by UVA lamps (λ = 365 nm)). Regulating the fatty acid composition through pre-incubation temperature adjustment demonstrated the crucial role of cell membrane fatty acid profile in bacterial susceptibility towards photocatalytic inactivation, while the lower coenzyme A level in coaA(-) mutant correlated well with its lower susceptibility towards photocatalytic inactivation. Furthermore, transmission electron microscopic study demonstrated the photocatalytic destruction process of bacterial cells. This is the first study using single-gene deletion mutants to explore better understanding of the photocatalytic inactivation mechanism of E. coli.
研究了细菌细胞成分（即脂肪酸谱和辅酶 A）在光催化细菌灭活中的作用。大肠杆菌 BW25113 作为“亲本菌株”及其同工基因缺失突变体大肠杆菌 JW1081（fabF(-)突变体）和大肠杆菌 JW3942（coaA(-)突变体）对二氧化钛（TiO(2)）的光催化灭活表现出不同的敏感性，UVA 灯（λ = 365nm）照射）。通过预孵育温度调节来调节脂肪酸组成，证明了细胞膜脂肪酸组成在细菌对光催化灭活的敏感性中的关键作用，而 coaA(-)突变体中辅酶 A 水平较低与其对光催化灭活的敏感性较低密切相关。此外，透射电子显微镜研究证明了细菌细胞的光催化破坏过程。这是首次使用单基因突变体研究来更好地理解大肠杆菌的光催化灭活机制。
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