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

• Published in: Biotechnology and bioengineering Vol. 85; no. 2; pp. 155 - 165
• Main Authors: Pursell, Mark R., Mendes-Tatsis, M. Alcina, Stuckey, David C.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 20.01.2004; Wiley
• Subjects: Biological and medical sciences; Bioreactors; biosurfactant; Biotechnology; Cell Culture Techniques - methods; cell debris; Chloramphenicol - biosynthesis; Chloramphenicol - isolation & purification; Culture Media - chemistry; Culture Media - metabolism; Fermentation - physiology; fermentation broth; fractionation; Fundamental and applied biological sciences. Psychology; Liquid-liquid extraction; mass-transfer; Membranes, Artificial; Methods. Procedures. Technologies; Motion; Others; Pilot Projects; Rheology - methods; Solutions; Streptomyces - chemistry; Streptomyces - isolation & purification; Streptomyces - metabolism; Surface-Active Agents - chemistry; Surface-Active Agents - metabolism; Ultrafiltration - methods; Various methods and equipments; Culture medium; Separation method; Fractionation; Liquid liquid extraction; Downstream processing; Surfactant; Fermentation; Mass transfer
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.10840

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. © 2003 Wiley Periodicals, Inc.