Antibiotic Activity of a Newly Discovered Aspergillus Species Isolated from Sewage Dump Site

Abstract

Infectious agents causing diseases are becoming resistant to drugs produced to manage them. This has continued to spur scientific investigations for newer and better antibiotics to aid and/or replace existing ones. Soil samples were collected from sewage dump sites with the sole aim of isolating and screening fungi species for antibacterial substances using the cultural method. A newly discovered fungi species of Aspergillus was used to produce crude antibiotic, fractionated by column chromatography and tested on clinical isolates – Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Candida albicans and Pseudomonas aeruginosa. The result of zones of inhibition was 45 mm, 47 mm, 48 mm, 49 mm and 47 mm in order of listing of organisms. Gas chromatography mass spectrometry analysis of the fractionated extract revealed the following compounds as being responsible for the observed inhibition – methylene chloride, heptanoic acid, octanoic acid, methyl hydrogen phthalate, 2,4-di-tert-butylphenol, dodecanoic acid, z-10-tetradecen-1-ol acetate, tetradecanoic acid, 2-tetradecyloxy-ethanol, n-hexadecanoic acid, hexadecanamide, octadecenamide and octadecanamide. A cocktail of organic compounds – fatty acids and amides that displayed strong antimicrobial ability, if well tapped, hold a future in the development of new antibiotics.