Resazurin-based 96-well plate microdilution method for the determination of minimum inhibitory concentration of biosurfactants.

Objectives: To develop and validate a microdilution method for measuring the minimum inhibitory concentration (MIC) of biosurfactants.

Results: A standardized microdilution method including resazurin dye has been developed for measuring the MIC of biosurfactants and its validity was established through the replication of tetracycline and gentamicin MIC determination with standard bacterial strains.

Conclusion: This new method allows the generation of accurate MIC measurements, whilst overcoming critical issues related to colour and solubility which may interfere with growth measurements for many types of biosurfactant extracts.