Antibacterial Activity of Linum usitatissimum L. Seeds and Active Compound Detection

In the present study, antibacterial properties of four different extracts from Linum usitatissimum L. seeds were screened against four types of Gram-positive and negative bacteria: Staphylococcus aureus, Bacillus cereus, Klebsiella pneumoniae and Pseudomonas aeruginosa using agar-well diffusion method and comparing their antibacterial activities with the antibiotics Ampicillin, Cefalexin, Chloramphenicol and Tetracycline. Petroleum ether extract demonstrated significant inhibitory effects against all tested bacteria using all extract concentrations compared with used antibiotics except chloramphenicol, the clearest activity was seen against K. pneumoniae using the extract concentration 50mg/cm3. Ethanol extract possessed considerable antibacterial activities against the pathogenic bacteria, the highest inhibitory effect was observed against B. cereus using the extract concentration 200mg/cm3, followed by aqueous extract which revealed good inhibitory action against Ps. aeruginosa using the same concentration. The weakest extract used was the chloroform extract which was only active against S. aureus. Thin-Layer Chromatography of petroleum ether extract indicated the presence of active fatty acids.