Analysis of phase composition in aqueous two-phase systems using a two-column chromatographic method: Application to lactic acid production by extractive fermentation

Planas, Jordi; Lefebvre, Denys; Tjerneld, Folke; Hahn‐Hägerdal, Bärbel

doi:10.1002/(sici)1097-0290(19970520)54:4<303::aid-bit2>3.0.co;2-o

Cited by 23 publications

(9 citation statements)

References 21 publications

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“…The work of KoÈ hler et al (1989) clearly con®rms both the diculty and potential success of such approaches in certain circumstances. Other workers have exploited chromatographic analyses to determine the concentrations of phase component chemicals in top and bottom phases (Planas et al, 1997;SebastiaÄ o et al, 1995), but such approaches require extensive sample preparation and method validation when applied to complex particulate systems.…”

Section: Introductionmentioning

confidence: 99%

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

Lebreton

Walker

Lyddiatt

2001

Biotech & Bioengineering

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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 (TLL(e)). The addition of biomass to ATPS increased TLL(e) 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.

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Section: Introductionmentioning

confidence: 99%

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

Lebreton

Walker

Lyddiatt

2001

Biotech & Bioengineering

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“…Separation of carboxylic acids and of phase components of EOPO-PEI-DEX and EOPO-PEI-WM systems, was performed by HPLC using a prepacked gel exclusion chromatography column (Ultrahydrogel 500, 300 × 7.8 mm i.d. ; Waters, Millipore Corp., Milford, MA) at 22°C (Planas et al, 1997). The mobile phase was a 0.005 M H 2 SO 4 water solution.…”

Section: Discussionmentioning

confidence: 99%

“…The use of PEI-based conjugates as phase-forming polymers, together with polysaccharides as second polymers, successfully shifted the partitioning of lactic acid to the conjugate-rich top phase. Lactic acid distributes evenly (Katzbauer et al, 1995) or to the bottom phase (Planas et al, 1997) of PEG-DEX systems. The highest value of K lac in EOPO-DEX systems, (i.e., K lac 1.3) was observed at pH 2 and decreased to 0.4 at pH 5.…”

Section: Discussionmentioning

confidence: 99%

“…The uneven partitioning of cells in an ATPS allows the removal of the product from the cell-free phase. ATPS have been used for the production of bulk chemicals (Drouin and Cooper, 1992;Jarzebski et al, 1992), and specifically for the production of lactic acid (Katzbauer et al, 1995;Kwon et al, 1996;Planas et al, 1996Planas et al, , 1997. However, an even distribution of lactic acid between the two phases, together with the cost of the poly-mers, makes this process concept economically nonviable.…”

Section: Introductionmentioning

confidence: 99%

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Novel polymer-polymer conjugates for recovery of lactic acid by aqueous two-phase extraction

Planas

Kozlowski

Harris

et al. 1999

Biotechnol. Bioeng.

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A new family of polymer conjugates is proposed to overcome constraints in the applicability of aqueous two‐phase systems for the recovery of lactic acid. Polyethylene glycol–polyethylenimine (PEI) conjugates and ethylene oxide propylene oxide–PEI (EOPO‐PEI) conjugates were synthesized. Aqueous two‐phase systems were generated when the conjugates were mixed with fractionated dextran or crude hydrolyzed starch. With 2% phosphate buffer in the systems, phase diagrams with critical points of 3.9% EOPO‐PEI–3.8% dextran (DEX) and 3.5% EOPO‐PEI–7.9% crude starch were obtained. The phase separation temperature of 10% EOPO‐PEI solutions titrated with lactic acid to pH 6 was 35°C at 5% phosphate, and increased linearly to 63°C at 2% phosphate. Lactic acid partitioned to the top conjugate‐rich phase of the new aqueous two‐phase systems. In particular, the lactic acid partition coefficient was 2.1 in 10% EOPO‐PEI–8% DEX systems containing 2% phosphate. In the same systems, the partitioning of the lactic acid bacterium, Lactococcus lactis subsp. lactis, was 0.45. The partitioning of propionic, succinic, and citric acids was also determined in the new aqueous two‐phase systems. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 66: 211–218, 1999.

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“…Successful applications of ATPS have been reported in enhancing the production of lactic acid by Lactococcus lactis [22], catalyzing acid acylation of 7-aminocephalosporanic acid with (R)-mandel by Penicillin G acylase [19] and recovering porcine pancreatic lipase more than 90% with a purification factor of approximately 3.4 [23]. To date, however, there is little published information on the stereo-selectivity of microbes in ATPS.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of substrate concentration in microbial stereoinversion through one-pot oxidation and reduction by aqueous two-phase system

2009

Bioprocess Biosyst Eng

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An extractive biocatalytic method of aqueous two-phase system was employed for stereoinversing (R)-1-phenyl-1,2-ethanediol into (S)-1-phenyl-1,2-ethanediol by Candida parapsilosis CCTCC M203011. It was observed that substrate and product inhibitions in microbial stereoinversion through one-pot oxidation and reduction were removed efficiently by extractive biocatalysis in aqueous two-phase system with PEG 4000/phosphate potassium system, and that the substrate concentration was enhanced from 15 to 30 g/L with product optical purity of 99.02% e.e. and yield of 90% after 60 h. Simultaneously, it was observed that change in cell morphology impedes the further enhancement of substrate concentration in this system but can be reversibly changed after stereoinversion or cultivation in systems without PEG.

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Analysis of phase composition in aqueous two-phase systems using a two-column chromatographic method: Application to lactic acid production by extractive fermentation

Cited by 23 publications

References 21 publications

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

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

Novel polymer-polymer conjugates for recovery of lactic acid by aqueous two-phase extraction

Enhancement of substrate concentration in microbial stereoinversion through one-pot oxidation and reduction by aqueous two-phase system

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