Bioassay-guided Isolation of Antibiotics from Selected Marine Fungi

Chong, Meng Shin (2011) Bioassay-guided Isolation of Antibiotics from Selected Marine Fungi. [Project Report] (Unpublished)


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The emergence of new life-threatening infectious diseases and rapid spread of antibiotic-resistant bacteria in nature have raised the awareness of researchers towards screening for novel antibiotics. In response to the marine environment as a potential source of novel secondary metabolites, a study of antibacterial activity in marine fungi isolates from marine biofilm was carried out. Three fungal isolates designated as 4.1.2, P 2.2.1 and P 1.8.2 screened for antibiotic activity using agar overlay technique against one Gram-positive, Staphylococcus aureus and three Gram-negative, Escherichia coli, Salmonella typhi and Enterobacter aerogenes test bacteria. Result showed that only isolate 4.1.2 exerted strong antibacterial activity against Staphylococcus aureus and Enterobacter aerogenes. In contrast, only weak antibacterial activity was obtained against Escherichia Coli and Salmonella typhi. Fungal isolates, 4.1.2, P 2.2.1 and P 8.1.2 were putatively identified using slide culture method up to genus level as Bipolaris sp., Endophragmia sp. and Penicillium sp., respectively. Hexane, chloroform, dichloromethane (DCM), ethyl acetate, water and methanolextracts from isolate 4.1.2 (Bipolaris sp.) were subjected to antibacterial screening against the four test bacteria using diffusion method. However, none of the extracts showed antibacterial activities. This result suggested that antimicrobial substances produced by Bipolaris sp. could be antimicrobial peptides, and thus failure in obtaining antimicrobial peptide activity could be due to the denaturation of protein-based antimicrobial. The result of thin layer chromatography demonstrated that solvent system DCM-ethyl acetate in ratio of 2:1 as a better solvent system for fractionation of DCM extract as three spots were visualized under UV light, and with vanillin solution. Further optimization of solvent system could be done for better seperation of DCM extract into distinct components. Further studies upon the antifungal activity of Bipolaris sp. can be taken into consideration as its antifungal property was detected against different fungal species.

Item Type: Project Report
Uncontrolled Keywords: Antibacterial activity, marine fungi, extracted antibiotic, thin layer chromatography, FSTS, 2011, Universiti Malaysia Sarawak, UNIMAS, universiti, university, Borneo, Malaysia, Sarawak, Kuching, Samarahan, IPTA, education, undergraduate, research
Subjects: Q Science > Q Science (General)
S Agriculture > S Agriculture (General)
Divisions: Academic Faculties, Institutes and Centres > Faculty of Resource Science and Technology
Depositing User: Karen Kornalius
Date Deposited: 05 Dec 2013 07:29
Last Modified: 25 May 2015 04:35

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