Please use this identifier to cite or link to this item: http://hdl.handle.net/10603/2270
Title: Studies on the isolation characterization and bioevaluation of secondary metabolites from Aspergillus Funiculosus Aspergillus Gorakhpurensis and Curvularia Oryzae
Researcher: Siddhardha, B
Guide(s): Murty, U S N
Keywords: Biotechnology
Upload Date: 18-Aug-2011
University: Jawaharlal Nehru Technological University
Completed Date: 2010
Abstract: Microbial diversity serves as potential source for the isolation of bioactive secondary metabolites. Fungi are the most versatile and diversified organisms, exploited for the isolation of therapeutics and agriculturally important metabolites from decades. Indigenous and unexploited fungi serve as a source to isolate new metabolites or known metabolites with new biological activities. In the present thesis, EtoAc extracts of thirty species of fungi indigenously available were evaluated against Gram-positive and negative bacteria for antibacterial activity and larvicidal activity against Spodoptera litura 4th instar larvae. Preliminary screening results reveals that Aspergillus funiculosus, Aspergillus gorakhpurensis and Curvularia oryzae exhibited significantly higher biological activities and warranted for further extensive studies. Chemical structures of the metabolites produced from these fungi were elucidated by 1H, 13C NMR and mass spectral data. Mode of action of the isolated bio active metabolites was established against the bacteria, fungi and S. litura larvae. Kojic acid, 3-phenylpropionic acid and butanoic acid were isolated from A. funiculosus. Antibacterial and antifungal activity of the kojic acid and 3-phenylpropionic acid demonstrated moderate activity against the test bacteria and fungi. Minimum inhibitory concentration (MIC), minimum bactericidal activity (MBC) and time-kill kinetic study results revealed the bacteriostatic nature of the metabolites. Scanning electron microscopic observations of the bacteria treated with metabolites reveals that the metabolites were not induced morphological changes. Moderate antifeedent (DC50= 180.64 and 113.26 Bg/cm2 for kojic acid and 3-phenylpropionic acid respectively) and larvicidal activity (LD50= 693.52 and 381.72Bg/ml respectively) were ascertained against 4th instar S. litura larvae.
Pagination: xxvi, 208p.
URI: http://hdl.handle.net/10603/2270
Appears in Departments:Faculty of Biotechnology

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01_title.pdfAttached File51.77 kBAdobe PDFView/Open
02_declaration.pdf69.63 kBAdobe PDFView/Open
03_certificate.pdf82.09 kBAdobe PDFView/Open
04_dedication.pdf25.74 kBAdobe PDFView/Open
05_acknowledgements.pdf64.99 kBAdobe PDFView/Open
06_abstract.pdf86.22 kBAdobe PDFView/Open
07_table of contents.pdf120.36 kBAdobe PDFView/Open
08_list of tables.pdf102.73 kBAdobe PDFView/Open
09_abbreviations.pdf56.17 kBAdobe PDFView/Open
10_chapter 1.pdf183.18 kBAdobe PDFView/Open
11_chapter 2.pdf702.83 kBAdobe PDFView/Open
12_chapter 3.pdf1.81 MBAdobe PDFView/Open
13_chapter 4.pdf1.49 MBAdobe PDFView/Open
14_chapter 5.pdf1.59 MBAdobe PDFView/Open
15_chapter 6.pdf126.07 kBAdobe PDFView/Open
16_references.pdf176.6 kBAdobe PDFView/Open
17_publications.pdf955.41 kBAdobe PDFView/Open


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