Effect of fermentation broth and biosurfactants on mass transfer during liquid–liquid extraction

Abstract

Mass transfer rates in liquid-liquid extraction processes can be seriously affected by the presence of surface-active contaminants. This is especially true of applications of a biotechnological origin, where the microorganism used in the process may produce the surface-active contaminants. An investigation into the effects of soluble and insoluble fermentation broth components on mass transfer using chloramphenicol extraction into octanol as the model system was conducted. Soluble components produced during fermentation were found to adsorb to the interface, where they reduced the overall mass transfer coefficient by up to 70%. After fractionation it was found that components in the weight range from 10-30 kDa had the greatest effect on mass transfer. Protein and phospholipid compounds of similar size were found to reduce the overall mass transfer coefficient to a similar extent to the broth components at concentrations around 0.001mg/l. The biomass produced during the fermentation also reduced mass transfer substantially, and it is likely that this was due to physical blockage of the interface.

Interactions between surfactants and biomass during liquid–liquid extraction

“…The concentration-time data obtained from experiments are analyzed using a model based on the two-film theory to yield values for overall mass-transfer coefficients. 7 The error in determining the overall mass transfer coefficient was found to be AE4.7%.…”

“…Before inoculation, all media and growth flasks were sterilized in an autoclave (Astell Hearson) at 121 C for 20 min. A previous study 7 had determined the effect of the media and fermentation broth components on mass transfer.…”

“…Earlier work related to this study 7 examined the effect of fermentation broth components on mass transfer, and this included examining the effect of media components and the resulting fermentation broth. In that research, it was found that compounds produced during fermentation caused a reduction in mass transfer.…”

A Simple and Effective Isocratic HPLC Method for Fast Identification and Quantification of Surfactin

“…The proposed method was also tested with surfactin synthesized from culture broth of B. subtilis ATCC 21332. This fermentation broth also contained other fermentation products and residues such as proteins, sugar, lipid compounds and different types of amino acids (Pursell et al 2004). The complex nature of B. subtilis ATCC 21332 culture broth makes identification and quantification of surfactin difficult.…”

Coextraction during reactive extraction of phenylalanine using Aliquat 336: Modeling extraction equilibrium

“…An extraction system involving the recovery of phenylalanine by the quaternary ammonium compound Aliquat 336 has been studied previously by a number of researchers (Haensel et al, 1986;Pursell, 2001;Scarpello and Stuckey, 2000;Uddin et al, 1990Uddin et al, , 1992. It has been shown that Aliquat 336 is an effective extractant for phenylalanine, with recovery yields of up to 95% being reported (Scarpello and Stuckey, 2000).…”