Characterization of Biosurfactant Produced Nmby Pseudomonas Aeruginisa Isolated from Domestic Liquid Waste

Biosurfactants are surface-active compounds produced by microorganisms, known for their ability to reduce surface and interfacial tension and enhance the bioavailability of hydrophobic substances, making them valuable in environmental remediation and industrial processes. This study was conducted to isolate, identify, and evaluate the biosurfactant production potential of Gram-negative bacteria from soils polluted with domestic liquid waste at ASUU restaurant and Motion Ground within the University of Ilorin, Kwara State, Nigeria. Soil samples were collected aseptically, and standard microbiological techniques were used for isolation and characterization of Gram-negative bacteria. Six isolates were obtained; Salmonella spp., Pseudomonas aeruginosa, Neisseria spp., Escherichia coli, Proteus spp., and Klebsiella pneumoniae. These were subjected to biosurfactant screening using haemolysis test, oil displacement test, emulsification index (E24), and drop collapse test. Pseudomonas aeruginosa (AS2) exhibited the highest biosurfactant activity, with β-haemolysis, an oil displacement zone of 9.0 cm², the highest E24 value (55.5%), and a crude biosurfactant yield of 1.37 g. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of the AS2 biosurfactant extract revealed the presence of surface-active compounds including fatty acid esters, alcohols, siloxanes, and ethers, indicative of glycolipid type biosurfactants. These results suggest that domestic liquid waste-polluted soils are promising sources of biosurfactant-producing bacteria. In particular, Pseudomonas aeruginosa demonstrated high biosurfactant yield and strong surface activity, making it a potential candidate for application in environmental cleanup and industrial formulations. The results indicate that polluted domestic environments can serve as reservoirs for biosurfactant-producing bacteria with potential industrial and environmental applications.