Screening of Bacterial Isolates from Spent Lubricating Oil Polluted Soil for Potential to Produce Biosurfactant

Abstract

Biosurfactants are surface – transitive biomolecules generated by microbes that have different capability in utilizing crude oil polluted soil, biosurfactants are better than chemical surfactants because of their cost effectiveness, complete degradability and environmentally friendly. The research focused in isolating, identifying and screening bacteria for potential of producing biosurfactants from spent lubricating oil polluted soil from automobile Mechanic Workshop Artillery Barrack, Kakuri, Kaduna, Kaduna state Nigeria. Soil samples were collected and processed. Bacteriological analysis of the soil sample was carried using standard methods. In all, fifteen (15) bacterial strains were isolated, identified and characterized following standard microbiological assay. The isolates include Pseudomonas aeruginosa (33%), Bacillus subtilis (20%), Bacillus cereus (27%), Staphylococcus aureus (13%) and Escherichia coli (7%) respectively with Pseudomonas having the highest occurrence while Escherichia coli had the least. The fifteen bacterial isolated were screened for potential of producing Biosurfactants using drop collapse, oil displacement as well as Emulsification activity (E-24) test. Nine isolates out of fifteen identified bacteria were positive for drop collapse test, displacement as well as emulsification activity (E-24) test. Isolate J12 had the highest emulsification activity of (43±0.2) followed by J6 (22±0.0) others are J9 (17±0.1). J15 (16±0.0), J2 (15±0.0), J10 (12±0.0), J13 (11±0.0), J1 (10±0.0) while no emulsification activity on J3, J4, J5, J7, J8, J11 and J14 . For oil displacement method, J12 had the highest with (4.1±0.0) followed by J6 and J15 having (3.0±0.0) each. J9 and J2 had 2.5±0.0 and 2.0±0.0 respectively.