Functional antimicrobial substance and their bioactive compounds extracted from secondary metabolites of Aspergillus terreus

Methods: Fungal isolates were isolated fromsoil samples using Potato Dextrose Agar (PDA). The plates were incubated at 25°C for 72 – 96 h and identification was based on molecular techniques by targeting 18S rRNA. Isolation of bioactive compounds from the extracts was carried out by GC-MS analysis. The extracted secondary metabolites was concentrated by evaporation of the solvents at room temperature. Concentrated extract was constituted by dissolving it in DMSO and stored at 4°C for antimicrobial assay.

Results: Two hundred and fifty six (256) fungal isolates were isolated and sixteen (16) of them showed promising antimicrobial potential. Phylogenetic tree showed evolutionary trend of the fungus with 99% similar to Aspergillus terreus. The broad spectrum activity of the antimicrobial substance were observed to be24.7±4.619 and 26.0±0.000 against Gram positive and negative respectively.The bioactive compounds isolated were phenols, amines, terpenes and fatty acid esters.

Conclusion: The functional and new antibiotics can be obtained from fungal family especially in this era of multi-drug resistant (MDR) bacteria. It is observed that there are functional antimicrobial substances associated with Aspergillus terreus. The extracted substances was found to be active against MDR bacteria in vitro. The bioactive compounds obtained from the GC MS analysis revealed the nature of compounds and some of these compounds have been documented in different areas of antimicrobial and related properties.