African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12278

Full Length Research Paper

Antibacterial activity of Sargassum polycystum C. Agardh and Padina australis Hauck (Phaeophyceae)

Chong Chiao-Wei1, Hii Siew-Ling2 and Wong Ching-Lee1,3*
1Department of Science, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman (UTAR), Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur, Malaysia. 2Department of Chemical Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman (UTAR), Jalan Genting Kelang, 53300 Setapak, Kuala Lumpur, Malaysia. 3School of Biosciences, Taylor's University Lakeside Campus, No .1, Jalan Taylors, 47500 Subang Jaya, Selangor D. E., Malaysia.
Email: [email protected]

  •  Accepted: 19 August 2011
  •  Published: 19 October 2011


Seaweeds are used in pharmaceutical and biochemical applications as they possess interesting biological activities that contribute to the discovery of natural therapeutic agents. In this study, the antibacterial activity of n-hexane, dichloromethane and methanolic extracts of brown seaweeds (Phaeophyceae), Sargassum polycystum C. Agardh and Padina australis Hauck, was examined using the disc diffusion and broth microdilution methods. The bioactivity of the seaweed extracts was expressed as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibacterial activity against Gram-negative bacteria (beta-lactamase positive and negative Escherichia coli,Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Bacillus cereus) was discussed. Gram-positive bacteria especially B. cereus was more susceptible to the seaweed extracts (MIC = 0.130 to 0.065 mg/ml). Generally,S. polycystum extracts exhibited higher bacteriostatic activity (lower MICs) against all the tested bacterial strains when compared with P. australis. However, P. australis extracts showed a narrow spectrum of bactericidal activity against B. cereus. n-Hexane extracts of S. polycystum exhibited promising bacteriostatic agents against B. cereus (MIC = 0.065 mg/ml) with MIC value lower than the standard MIC of potential antimicrobial drug (0.100 mg/ml). Since only crude seaweed extracts were tested in this study, further purification and isolation of bioactive compounds from the extracts are essential in future studies in order to optimize their antibacterial activity.  


Key words: Phaeophyceae, disc diffusion test, minimum bactericidal concentration (MBC), minimum inhibition concentration (MIC).