Response Surface Methodology for Optimizing the Production of Biosurfactant by Candida tropicalis on Industrial Waste Substrates

Abstract

Biosurfactant production optimization by Candida tropicalis UCP0996 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−1 and 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.

Nano-fluid viscosity screening and study of in situ foam pressure buildup at high-temperature high-pressure conditions

“…From the table, all the data in each case were in reasonable agreement because the observed p values are less than 0.05 with good R 2 near 1.0. Real statistical data are recognized based on p and R 2 values, and good data must have a strong confidence interval (> 90%) at p < 0.05 for the model to be significant and the lack of fit not significant, respectively (Almeida et al 2017). The interaction effects of MFomax*aging 2 and aging 3 in the MFomax/SiO 2 NF are not significant (p > 0.05) after reducing the model to eliminate the non-significant terms; therefore, they could be ignored.…”

Biosurfactants: Production and application prospects in the food industry

“…Studies with C. tropicalis have increased the production scale in bioreactors combined with the use of industrial and agricultural by-products to increase yield and lower costs, achieving a product with considerable potential in the dispersion test of oil on the surface of water. 98 Other studies also report the production of a biosurfactant with the structure of a sophorolipid by the same yeast, achieving promising results in the emulsification of hydrophobic compounds. 99 The use of waste products for the production of biosurfactants is also possible when C. sphaerica is cultured in the medium, enabling good results in terms of surface tension, the emulsification index, along with stability under adverse environmental conditions.…”

BIOSSURFACTANTE PRODUZIDO PELA LEVEDURA Candida utilis: PRODUÇÃO E ISOLAMENTO

“…Segundo Luna et al (2013), surfactantes que são capazes de reduzir a tensão superficial da água de 72 para 35 mN.m -1 e a tensão interfacial frente o n-hexadecano de 40 para 1 mN.m -1 são considerados bons agentes. Comparando-se o valor de tensão superficial obtido com os valores apresentados por Almeida et al (2017) utilizando-se a C. tropicalis UCP0996 em um meio contendo 2,5% de melaço de cana-de-açúcar, 2,5% de óleo de fritura e 2,5% de licor de milho, os valores são bastante próximos: 34,12 ± 0,07 mN.m -1 (biorreator 2 L) e 35,60 ± 0,05 mN.m -1 (biorreator 50 L). Em relação à tensão interfacial, de acordo com Santos et al (2016), esta é considerada baixa para valores abaixo de 7 mN.m -1 .…”