title: Response Surface Methodology for Optimizing the Production of Biosurfactant byCandida tropicalison Industrial Waste Substrates.
abstract: Biosurfactant production optimization byCandida tropicalisUCP0996 was studied combining central composite rotational design (CCRD) and response surface methodology (RSM). The factors selected for optimization of the culture conditions were sugarcane molasses, corn steep liquor, waste frying oil concentrations and inoculum size. The response variables were surface tension and biosurfactant yield. All factors studied were important within the ranges investigated. The two empirical forecast models developed through RSM were found to be adequate for describing biosurfactant production with regard to surface tension (R2= 0.99833) and biosurfactant yield (R2= 0.98927) and a very strong, negative, linear correlation was found between the two response variables studied (r= -0.95). The maximum reduction in surface tension and the highest biosurfactant yield were 29.98 mNm-1and 4.19 gL-1, respectively, which were simultaneously obtained under the optimum conditions of 2.5% waste frying oil, 2.5%, corn steep liquor, 2.5% molasses, and 2% inoculum size. To validate the efficiency of the statistically optimized variables, biosurfactant production was also carried out in 2 and 50 L bioreactors, with yields of 5.87 and 7.36 gL-1, respectively. Finally, the biosurfactant was applied in motor oil dispersion, reaching up to 75% dispersion. Results demonstrated that the CCRD was suitable for identifying the optimum production conditions and that the new biosurfactant is a promising dispersant for application in the oil industry.
authors.affiliation: Northeast Biotechnology Network, Federal Rural University of PernambucoRecife, Brazil; Advanced Institute of Technology and InnovationRecife, Brazil.
authors.forename: Darne G
authors.initials: DG
authors.lastname: Almeida
authors.affiliation: Northeast Biotechnology Network, Federal Rural University of PernambucoRecife, Brazil; Advanced Institute of Technology and InnovationRecife, Brazil.
authors.forename: Rita de Cássia F
authors.initials: RC
authors.lastname: Soares da Silva
authors.affiliation: Advanced Institute of Technology and InnovationRecife, Brazil; Center of Sciences and Technology, Catholic University of PernambucoRecife, Brazil.
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Luna
authors.affiliation: Advanced Institute of Technology and InnovationRecife, Brazil; Center of Sciences and Technology, Catholic University of PernambucoRecife, Brazil.
authors.forename: Raquel D
authors.initials: RD
authors.lastname: Rufino
authors.affiliation: Advanced Institute of Technology and InnovationRecife, Brazil; Center of Sciences and Technology, Catholic University of PernambucoRecife, Brazil.
authors.forename: Valdemir A
authors.initials: VA
authors.lastname: Santos
authors.affiliation: Northeast Biotechnology Network, Federal Rural University of PernambucoRecife, Brazil; Advanced Institute of Technology and InnovationRecife, Brazil; Center of Sciences and Technology, Catholic University of PernambucoRecife, Brazil.
authors.forename: Leonie A
authors.initials: LA
authors.lastname: Sarubbo
keywords: Candida tropicalis; biosurfactant; oil dispersion; optimization; scale up