The Potential of Clove Essential Oil Microemulsion as an Alternative Biocide Against Pseudomonas aeruginosa Biofilm

Biocorrosion phenomenon is known to be detrimental in oil and gas industry. Synthetic biocides have been widely used to eliminate microorganisms which promote biocorrosion. However, these biocides are known to be toxic and harmful to the environment. One of the natural agents that potentially serves as an alternative for biocide is clove essential oil which has antimicrobial constituents and also have been shown to inhibit quorum sensing (QS) process of Pseudomonas aeruginosa. In this study, clove essential oil extracted from clove bud and stem were formulated into microemulsion and evaluated for its antibiofilm and anti-QS activity. To observe its antibiofilm activity, minimum inhibitory concentration (MIC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradicating concentration (MBEC) of clove bud and stem essential oils were determined by microdilution method in microtiter 96 well-plate. Anti-QS activity was observed by analyzing clove bud and stem essential oil effect against P. aeruginosa’s extracellular protease activity and swarming motility. The MIC value of clove bud and stem essential oils microemulsions were 0,33% and 0,5%, while MBIC50% values for clove bud and stem essential oil were 0,33% and 0.5%. However, MBEC value for both clove essential oil could not be determined. In addition, 0.66% clove bud essential oil and 1% clove stem essential oil successfully inhibited extracellular protease activity and swarming motility of P. aeruginosa by 32.06% and 45.56% for clove bud, and 31.43% and 45% for clove stem, respectively.