Antibiofilm and antioxidant activity of Rosmarinus officinalis essential oil

The aim of the work was to explore the antioxidant potential and antibiofilm activity of the Rosmarinus officinalis essential oil. The DPPH method was used to determine the antioxidant activity. The agar microdilution method was used to determine the minimum biofilm inhibiting concentration (MBIC). The MALDI-TOF MS Biotyper was used to evaluate the antibiofilm activity on the wood and glass surface. Vapor phase antimicrobial analysis was used to determine the effect on the food model. The antioxidant activity was 28.76 % ± 2.68 %. The MBIC for Stenotrophomonas maltophilia was 25 µL.mL-1 and for Bacillus subtilis 12.5 µL.mL-1. Analysis of the mass spectra of S. maltophilia revealed an inhibitory effect from the 5th, which persisted until the end of the experiment. Analysis of the mass spectra of B. subtilis showed an inhibitory effect from the 7th of the experiment. The experiments showed an effect on both tested surfaces. The food model showed a more pronounced effect of the Rosmarinus officinalis essential oil against B. subtilis. We assume that the effect of the essential oil is to disrupt the polysaccharide structure of the biofilm and consequently reduce the resistance of the biofilm. We have established that MALDI-TOF MS Biotyper is a suitable tool for evaluating changes in biofilm structure and could find more significant application for the study of biofilms in food and clinical practice.