Bioassay-guided isolation of antibiotics from selected marine fungi
The emergence of new life-threatening infectious diseases and the 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...
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| Format: | Final Year Project Report / IMRAD |
| Language: | English |
| Published: |
Universiti Malaysia Sarawak, (UNIMAS)
2011
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| Subjects: | |
| Online Access: | http://ir.unimas.my/id/eprint/1202/ http://ir.unimas.my/id/eprint/1202/8/2013-11-prCmShinfull.pdf |
| Summary: | The emergence of new life-threatening infectious diseases and the 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 8.1.2 screened for antibiotic activity using agar overlay technique against one Gram-positive,
Staphylococclls aurells 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 (OCM), ethyl acetate, water and
methanol extracts from isolate 4.1.2 (Bipolaris sp.) were subjected to antibacterial screening against the four
test bacteria using disc 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 OCM-ethyl acetate
in ratio of 2: 1 as a better solvent system for fractionation of OCM extract as three spots were visualized under UV light, and with vanillin solution. Further optimization of solvent system could be done for better
separation of OCM 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. |
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