Antibacterial and antibiofilm activities of polysaccharides, essential oil, and fatty oil extracted from Laurus nobilis growing in Lebanon.

OBJECTIVE

To evaluate the antibacterial activity of the extracts of Laurus nobilis against three Gram-positive bacteria (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212 and Staphylococcus epidermidis CIP 444) and two Gram-negative bacteria (Escherichia coli ATCC 35218 and Pseudomonas aeruginosa ATCC 27853). Also, the antibiofilm activity has been investigated against the biofilm produced by Staphylococcus epidermidis CIP 444.

METHODS

The polysaccharides, essential oil, and fatty oils extracted from the plant were used in broth microdilution methods to study the minimal inhibitory concentration, and then the minimal bactericidal concentration was determined.

RESULTS

The results showed that alginate, fucoidan, fatty oils and essential oil have good antibacterial activities against the 5 bacterial strains, and a negligible biofilm eradication activity of fucoidan, laminaran, fatty oil, and essential oil was observed, but a promising biofilm eradication activity was obtained with alginate, which showed a reduced biofilm mass even at low concentration.

CONCLUSIONS

The extracts obtained have promising antibacterial capacities which need further investigation for them to be incorporated in medical or nutritional applications.