Characterization of aqueous two-phase partition systems by distribution analysis of radiolabeled analytes (DARA): Application to process definition and control in biorecovery

• Published in: Biotechnology and bioengineering Vol. 77; no. 3; pp. 329 - 339
• Main Authors: Lebreton, Bénédicte, Walker, Simon G., Lyddiatt, Andrew
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 05.02.2002; Wiley
• Subjects: Amino acids; Amino Acids - analysis; Amino Acids - chemistry; aqueous two-phase systems; Biological and medical sciences; Biomass; biomass impact; Biotechnology; Biotechnology - instrumentation; Biotechnology - methods; Characterization; Chemical Fractionation - instrumentation; Chemical Fractionation - methods; Chromatography, High Pressure Liquid; Chromatography, Liquid - methods; Escherichia coli; Feedstocks; Fundamental and applied biological sciences. Psychology; hydrophobic factor; Hydrophobicity; Isotope Labeling; Methods. Procedures. Technologies; Molecular weight; Others; partition behavior of amino acids; pH effects; Polyethylene glycols; Polyethylene Glycols - chemistry; Purification; relative hydrophobicity; Solvents - chemistry; Thermodynamics; Various methods and equipments; whole blood processing; Separation method; Partition; Biphasic system; Purification; Aminoacid; Hydrophobicity; Aqueous solution
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.10005

In this article, we describe a characterization method applicable to aqueous two‐phase systems (ATPS) heavily loaded with complex biological feed‐stocks. We also studied the partition behavior of mixtures of traceable and quantifiable radiolabeled amino acids, selected on the basis of their relative hydrophobicity A unique linear relation was established between the tie‐line length (TLL: commonly determined by graphical methods) and the hydrophobic factor (HF) for ATPS comprising potassium phosphate and PEG alone, and validated for polymer molecular weights from 300 to 8000 Da in systems operated at an apparent pH value of 7.5. Radiolabeled amino acids were subsequently applied to the characterization of ATPS loaded with whole bovine blood by the determination of effective tie‐line lengths (TLLe). The addition of biomass to ATPS increased TLLe relative to that of blank ATPS of equivalent original composition of PEG and phosphate. In addition, an increase of biomass loading (variously sourced from blood, yeast, and E. coli) contributed to phase formation and stabilization of loaded ATPS in respect of system sensitivity toward operational conditions. The controlled application of sensitive ATPS (adjacent to the binodal curve) could thus be reconsidered for further application of aqueous two‐phase partitioning as a primary purification process. The application of effective tie‐line determinations by distribution analysis of radiolabeled analytes (DARA) as a process‐aid in the design and operation of ATPS in biorecovery is discussed. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 329–339, 2002.