Biosurfactants were produced using Pseudomonas sp, A. vinelandii and a consortium of A. vinelandii and Pseudomonas species using crude oil as substrate. The result of the Bacterial Adhesion To Hydrocarbon (BATH) shows 18.81 ± 4.32 %, 3.79 ± 0.82 % and 10.52 ± 276% for Pseudomonas sp., A. vinelandii and a consortium (Pseudomonas sp. and A. vinelandii) respectively, while producing 1.03 ± 0.03, 0.08 ± 0.02 and 1.22 ± 0.03 mg of biosurfactant/100ml from the cell free broth respectively. The emulsification of the biosurfactant from the consortium of Pseudomonas sp. and A. vinelandii in crude oil, diesel oil and kerosene are stable over a wide range of temperature and pH. The Fourier Transform Infrared (FTIR) analysis show that the Pseudomonas sp produced a rhamnolipid biosurfactant while that of A. vinelandii and the consortium produced a lipoprotein kind of biosurfactant respectively. This suggests that A. vinelandii might be utilizing rhamnolipid biosurfactant produced by Pseudomonas sp for energy in addition to the crude oil and that the type of association existing between the organisms is a symbiotic association in which the A. vinelandii depends on the exopolymer produced by Pseudomonas sp. in addition to the breakdown of crude oil.
Keywords: Biosurfactant, consortium, lipopeptide, exopolymer, hydrocarbon and crude oil