Neglected antibacterial activity of ethylene glycol as a common solvent

For the first time, the antibacterial activity of ethylene glycol (EG), a routine frequently used solvent against Escherichia coli (E. coli) bacterium, was assessed. The antibacterial activity of EG against E. coli was measured using colony counting and broth turbidity assays. The influence of EG concentration (1.5-25.0%v/v) and exposure time on the growth of E. coli was investigated. By increasing EG concentration, its antibacterial activity against E. coli increased so that for 24.0% of EG, the bacteria growth was totally inhibited within 4 h. The MIC and MBC values of EG are 18.0 and 24.0%v/v, respectively. Since the ratio of MBC to MIC is less than four, EG acts as a bactericidal agent. Also, a model for the slopes of the linear part of the growth curves was proposed. The SEM images of bacteria cells before and after exposure to EG show that most E. coli were seriously distorted.