Optimization of liquid–liquid extraction of biosurfactants from corn steep liquor

Abstract

In this work, the optimization of the operational conditions for the chloroform-based extraction of surface-active compounds from corn steep liquor (CSL) was carried out and the nutritional properties of the remnant aqueous phase (CSL-less biosurfactant) was evaluated as microbial fermentation medium. The optimal conditions to obtain biosurfactants from CSL were as follows: chloroform/CSL ratio 2 (v/v), 56 °C at extraction times >30 min. At the optima conditions, 100 % of biosurfactant extract can be obtained from CSL, obtaining 12.0 ± 0.5 g of biosurfactant extract/Kg of CSL. The critical micelle concentration (CMC) of the biosurfactant extract was 399.4 mg L(-1). This value is similar to the CMC of cetrimonium bromide (CTAB), a cationic surfactant used in the formulation of nanoparticles. The extraction of biosurfactant can be also carried out at room temperature although in this case, the extraction yield decreased about 15 %. The extraction of surface-active compounds from agroindustrial streams can suppose important advances for the bio-based surfactants industry. Biosurfactants obtained in this work are not only more eco-friendly than chemical detergents but also can be cost competitive with its chemical counterparts. Furthermore, after the extraction of surface-active compounds, CSL-less biosurfactant was found to be suitable as nutritional supplement for lactic acid bacteria, maintaining its nutritional properties in comparison with regular CSL.

Biogenic Synthesis of Metal Nanoparticles Using a Biosurfactant Extracted from Corn and Their Antimicrobial Properties

“…Finally, the bands at 1168, 1243 cm −1 1645 cm −1 indicate the presence of fatty acids. Therefore the FTIR analysis confirmed that the extracted biosurfactant comprises lipids and proteins showing a good agreement with the previously reported [30,31]. …”

“…The biosurfactant produced by spontaneous fermentation of lactic acid bacteria on CSL was extracted by using the protocol recently improved by Vecino and co-workers [30]. After a filtration step to remove some large insoluble molecules, the extract was characterized by Fourier Transform infrared spectroscopy (FTIR) spectroscopy.…”

“…The biosurfactant (BS) extraction was carried out using a liquid-liquid extraction process, with a CSL: organic phase ratio of 1:2 ( v / v ), at 150 rpm, for 1 h and at a temperature of 56 °C, following the protocol established by Vecino et al [30]. Once the biosurfactant was extracted, it was dissolved in the same volume of water present at the beginning of the extraction process.…”

“…Therefore, biosurfactants produced by lactic acid bacteria can be considered as non-toxic. Vecino and coworkers [30] have recently found that corn steep liquor (CSL) contains important concentrations of natural biosurfactant, 12.0 ± 0.5 g/Kg of CSL, which is probably produced, as a secondary metabolite, by the lactic acid bacteria that grow spontaneously in the CSL and prevent the growth of pathogenic microorganisms. Taking this into account, the aim of the present work is to exploit the use of the lipopeptide biosurfactant extracted from CSL for the synthesis of Au and Ag NPs in a “one-step” green protocol.…”

Wastewater treatment enhancement by applying a lipopeptide biosurfactant to a lignocellulosic biocomposite

“…After extraction, the biosurfactant was separated from the chloroform by rotary evaporation (Buchi R-210, Switzerland) at a pressure of 474 mbar and 60 • C, following the methodology proposed by Vecino, Barbosa-Pereira, et al (2015).…”