Antibacterial activity of malaysian edible herbs extracts on fish pathogenic bacteria

Abstract

The study was conducted to investigate the antibacterial properties of five edible herbs against fish pathogenic bacteria. Herbs extracts including black pepper (Piper nigrum), clove (Syzygium aromatic urn), curry leaf (Murraya koenigii), onion (Allium cepa) and Vietnamese coriander (Persicaria odorata) were screened against nine common fish pathogens namely Escherichia coli, Edwardsiella tarda, Aeromonas hydrophila, Citrobacter freundii, Vibrio parahaemolyticus, Vibrio vulnificus, Staphylococcus aureus, Streptococcus agalactiae and Streptococcus anginosus. Methanol extracts of S. aromaticum showed antibacterial properties against V. parahaemolyticus, V. vulnificus, S. aureus and S. anginosus with Minimum Inhibitory Concentration (MIC) values of 1.56, 3.13, 3.13 and 0.78 mg mL-1, respectively. Water extract of S. aromaticum exhibited activity against A. hydrophila and S. aureus with MIC values of 12.5 and 50.0 mg mL-1, respectively. Methanol extract of M. koenigii was active against S. agalactiae and its MIC was 0.39 mg mL-1 while methanol extract of P. odorata was active against S. aureus and its MIC was 3.13 mg mL-1. For the heat stability test, methanol extract of S. aromaticum showed activity at temperatures of 37, 47, 57, 97 and 105°C with 7 to 8 mm in diameter of inhibition zone while another herbs were only active at 37°C. In general, methanol extract of S. aromaticum showed the greatest antibacterial activity among all herbs extracts tested. © 2011 Academic Journals Inc.