Due to the increase in the antimicrobial resistance, there is an unprecedented need for the discovery of novel antimicrobial drugs. Bioactive compounds produced naturally by marine seagrasses are promising agents for development of novel antimicrobial compounds. In this study, the antibacterial and antibiofilm performances of the rhizomes of Posidonia oceanica (L.) Delile collected within the shores of Northern Cyprus were investigated.
Samples were extracted via maceration using dichloromethane, chloroform, methanol, ethanol and acetone. The methanolic extraction exhibited two layers of crude extract: Viscous (ME1) and pulverant (ME2). Antibacterial activity was investigated against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603 by disk diffusion and broth microdilution methods. Biofilm inhibition performance of the sub-MIC concentrations of the extracts with notable antibacterial activities was investigated via microtiter plate assay using crystal violet.
None of the extracts showed any inhibition zone against the tested microorganisms. Minimum inhibitory concentration (MIC) of rhizome extracts are shown in Table 1. Furthermore, MBC of EE was >4 and 1 mg/ml, whereas that of ME1 and ME2 was >4 and 2 mg/ml against S. aureus and E. faecalis, respectively. EE inhibited biofilm growth by 78.6% at 0.5 mg/mL for E. faecalis and 87.6% at 0.25 mg/mL for S. aureus. ME1 significantly inhibited the biofilm growth by 92.1% at 1 mg/mL for E. faecalis and by 94.1% at 0.5 mg/mL for S. aureus. ME2 displayed weaker inhibition of biofilm growth of E. faecalis and S. aureus by 87.5% at 0.5 mg/mL and 83.3% at 0.5 mg/mL (Figure 1), respectively.
Anahtar Kelimeler: Antibacterial, antibiofilm, extract, natural products, Posidonia oceanica