Bioremediation of contaminated diesel and motor oil through the optimization of biosurfactant produced by Paenibacillus sp. D9 on waste canola oil

The potential of the indigenously isolated biosurfactant producing organism, Paenibacillus sp. D9 to use waste frying oils (canola, sunflower, castor, and coconut) were evaluated as alternate cheap substrates for biosurfactant synthesis. The optimum parameters, functional properties, and applicability for bioremediation of the as-synthesized biosurfactant were assessed. Initial biosurfactant yield showed 2.11 g/L and 33.7 mN/m, a representative of low production. An improvement on maximum reduction in surface tension and biosurfactant yield of 31.2 mN/m and 5.31 g/L, respectively, was noted since the two quadratic models were adequate with regards to biosurfactant yield (R² = 0.9937) and surface tension (R² = 0.9862). The proficiency of biosurfactant when contrasted to a chemical surfactant led to the degradation of 73.2% motor oil, 71.8% diesel (shaking condition), 63.3% motor oil, and 59.3% diesel (static condition) in a solid environment. Meanwhile, using an aqueous environment, bio-removal of 77.6% motor oil, 74.3% diesel (shaking condition), 62.2% motor oil, and 57.4% diesel (static condition), respectively, was observed. The response surface methodology tool was suitable in identifying the optimum conditions on low-cost substrates and the biosurfactant is capable for bioremediation of diesel and motor and from contaminated environment.