Antimicrobial mechanism analysis of an oil-in-water micro-emulsion by DNA microarray-mediated transcriptional profiling of Escherichia coli

The DNA microarray was employed in this study to investigate the gene expression profiles of Escherichia coli treated by an oil-in-water (o/w) microemulsion, in order to better understand the antimicrobial mechanism of the microemulsion as a promising food-grade antimicrobial system. 5,440 open reading frames (ORFs) of E. coli were investigated. 5 ml bacterial cultures with a known inoculum of E. coli cells (1.0 × 109 cfu/ml) was added at 1:1 (v/v) to the microemulsion and incubated on a tube rotator at 200 rpm for 4 h at 37 °C for the subsequent DNA microarray analysis.