Pakistan Research Repository


Ali, Rashda (1984) PRIMARY METABOLITIES OF ASPERGILLUS FLAVIPES. PhD thesis, University of Karachi, Karachi.



Studies on the primary metabolites of Aspergillus flavipes were carried out. Proteins and peptides were isolated from the cell-free-broth and fungal-mass of Aspergillus flavipes. Some of these were found to be biologically active. A high molecular weight trypsin inhibitor of 40,000 ± 5000 dalton isolated, purified and characterized. Two new proteolytic enzmes, one from cell-free-broth and the other from fungal mass have been isolated and some of their physico-chemical properties are reported. The proteinase from fungal mass showed antifungal and antibacterial activities. A low molecular weight protein isolated from mycelial cells was found to act against Staphylococcus aureus and Sheigella dysentariae. The amino acid composition of these are reported. Five peptides have been isolated from cell-free-broth which exhibited antifungal and antibacterial activities. The compositions of these peptides are reported. A number of peptides present in the fungal-mass were separated and six of them were studied fro their amino acid composition. The amino acids synthesized by A. flavipes were analysed and the nutritional value of the fungal proteins evaluated. Organic acids and simple sugars produced by the fungus are also reported. These metabolites were not found to be synthesized in any significant quantity. The growth of A. flavipes on various synthetic media showed that urea and glycine are not used as sole carbon sources. Several of the rotten vegetables and fruits were successfully used as substrate for culture of A.flavipes and A.niger. Yield of fungal-mass was more on rotten vegetables and fruits than on Czapek synthetic medium. Acid sterilization was found to be an economical process as compared to autoclaving suggesting its industrial usage. Single-cell protein obtained from A.flavipes and A. flavipes and A.niger showed the presence of all the essential amino acids. Thus a high quality protein, at a low cost was produced by utilization of waste vegetables and fruits which may be used as animal feed and other similar purposes.

Item Type:Thesis (PhD)
Uncontrolled Keywords:aspergillus flavipes, amino acids, proteins, organic acids, toxins, alkaloids, enzymes, fermentation, peptides, carbohydrates, organic acids, waste vegetable
Subjects:Physical Sciences (f) > Chemistry(f2)
ID Code:831
Deposited By:Mr. Muhammad Asif
Deposited On:27 Oct 2006
Last Modified:04 Oct 2007 21:02

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