Effect of various solvents on bacterial growth in context of determining MIC of various antimicrobials

Dimethyl sulfoxide (DMSO) and ethanol are frequently used as solvent for natural as well as synthetic antibacterial compounds, in order to determine their MICs. Effect of these solvents on bacterial growth is an important factor to be considered, while considering reproducibility of experiments for MIC determination. Present study aimed at determining the effect of different concentrations (1% to 6%) of DMSO, ethanol, and methanol on the growth of five different bacteria. DMSO scored better followed by methanol and ethanol, in terms of their compatibility with MIC determination. Lower concentrations of solvents, which apparently do not affect the bacterial growth significantly, may still potentiate the effect of antibacterial compound under test.