Evaluation of antibacterial and anti-biofilm effects of carvacrol and eugenol on bacteria isolated from the Persian Gulf waters

The formation of microbial biofilms is one of the key steps in marine fouling. Therefore, the development of anti-biofilm strategies, especially through research on environmentally friendly antifouling materials, can help control biofouling. The present study was performed to evaluate the antibacterial and anti-biofilm activity of carvacrol and eugenol against marine bacteria isolated from Persian Gulf waters. In disk diffusion method, Vibrio sp. (KM1) bacteria showed more sensitivity against carvacrol and eugenol with a growth inhibition zone diameter of 17±0.3 and 15±0.5mm, respectively. Minimum inhibitory concentration (62.5µg/mL) and minimum bactericidal concentration (125µg/mL) were also obtained with carvacrol against KM1. In this study, the inhibitory effect of carvacrol and eugenol on biofilm formation by Pseudoalteromonas sp. (PH18) using tissue culture plate method (TCP) was investigated and 4MIC concentration showed the highest biofilm inhibition (carvacrol 90% and eugenol 87%). Based on the results, carvacrol and eugenol can be used as an alternative in antifouling coatings due to their appropriate anti-biofilm activity against marine bacteria.