Deepika Koyappayil, Sooraj S. Nath, Smitha K.V. and Kunhi A.A.M. 2016. Activity of Antimicrobial Metabolites Produced by Aspergillus sp. S-CSR0024 against Multi Drug Resistant E.coli S-CSR0025, Pseudomonas aeruginosa S-CSR0026 and Staphylococcus aureus S-CSR0027. Abstract Book. National symposium on ‘Biosciences and Technology –Recent Developments and Future Prospects’, SIAS-Centre for Scientific Research, Safi Institute of Advanced Study, Vazhayoor, Malappuram, Kerala, p. 58.

ABSTRACT

An investigation was carried out to determine the presence of antibiotic-producing fungus from the soil environment. Soil samples were collected from different locations for the isolation of fungi. Pour plate method involving serial dilution was used for the isolation of fungus. The media used for the isolation were Sabouraud dextrose agar (SDA), Potato Dextrose Agar (PDA). Screening of antibiotic producing organism was done by cross streak method. Inability of Multidrug resistant Staphylococcus aureus to grow in the presence of Aspergillus sp. suggests antibiotic production by Aspergillus sp.and showed a zone of inhibition of 12 mm in Mueller Hinton Agar media by agar well diffusion method. Microorganisms were characterized by saline wet mount and LPCB staining technique was Aspergillus sp., named as Aspergillus sp. S-CSR-0024. Sensitivity test with Multidrug resistant Escherichia coli,named as Escherichia coli. S-CSR-0025, Pseudomonas aeruginosa named as Pseudomonas aeruginosa S-CSR-0026and Staphylococcus aureus named as. Staphylococcus aureus S-CSR-0027 as test organisms were employed to determine the ability of the fungal isolates to produce antimicrobial compounds. The minimum inhibitory concentration of Staphylococcus aureus S-CSR-0027 was 1000μl.In order to improve its efficiency, the effect of medium, temperature, pH, inoculums concentration and drug concentration were optimized and its productivity was examined by agar well diffusion method and tube dilution method against Multidrug resistant Staphylococcus aureusS-CSR-0027. There was no turbidity in the test tubes containing the smallest drug concentrations 5, 10, 15μl. while the turbidity kept increasing with the increase in the size of the inoculums from 20-30μl and the optimal inoculum concentration was 2% inoculum concentration of Aspergillus sp. S-CSR-0024. Sabouraud Dextrose broth to be the effective culture media for maximum antibiotic production by showing 12 mm zone of inhibition for Staphylococcus aureusS-CSR-0027 with an optimal temperature of 30° C and pH 10.The results from this study confirmed that the antibacterial substance produced by Aspergillus sp. S-CSR-0024were found to be more effective. 

 

Key words: Aspergillus sp., Antimicrobial compound, Multidrug resistant organisms.