Co-reporter:Camilo S. López-Garzón, Luuk A.M. van der Wielen, Adrie J.J. Straathof
Separation and Purification Technology 2017 Volume 175() pp:9-18
Publication Date(Web):24 March 2017
DOI:10.1016/j.seppur.2016.11.018
•Fumarate, itaconate, malate and succinate have comparable ion-exchange equilibria.•The same model was valid for sorbent-type and extractant-type ion-exchangers.•Sorption led to a better exchange than extraction.•Hydroxide gave a better exchange than chloride.Ion-exchange can be used for primary recovery of aqueous dicarboxylic acids at neutral pH, where there is almost complete acid dissociation. The equilibria of anion exchange of aqueous dicarboxylate anions (fumarate, itaconate, malate and succinate) with anions (Cl− and OH−) bound to quaternary ammonium compounds (Aliquat extractant and Dowex sorbent) were quantified. All equilibria could be described by the same model. The four dicarboxylates behaved similarly, and were exchanged by two Cl− or OH− anions. Sorption gave a much better exchange than extraction and OH− gave a much better exchange than Cl−. In batch equilibrium experiments most Cl− is not exchanged by dicarboxylate, pointing at the importance of column operation.
Co-reporter:Carlos I. Cabrera-Rodríguez;Laura Paltrinieri;Louis C. P. M. de Smet;Luuk A. M. van der Wielen;Adrie J. J. Straathof
Green Chemistry (1999-Present) 2017 vol. 19(Issue 3) pp:729-738
Publication Date(Web):2017/02/06
DOI:10.1039/C6GC01391K
The recovery of carboxylic acids from fermentation broth is one of the main bottlenecks for the industrial production of bio-based esters. This paper proposes an alternative for the recovery of carboxylates produced by fermentations at pH values above the pKa of the carboxylic acid. In this approach, the aqueous carboxylate anion is recovered using anion exchange, followed by desorption and esterification with CO2-expanded alcohols. Using CO2-expanded methanol, we achieved a high desorption yield at 10 bar of CO2 and 20 °C. An ester yield of 1.03 ± 0.07 mol methyl acetate/acetatein was obtained for the combined desorption–esterification at 5 bar of CO2 and 60 °C. The proposed process has low chemical consumption and low waste production. The proposed process works, with a lower yield, for other carboxylates (e.g. lactate and succinate) and alcohols (e.g. ethanol).
Co-reporter:Carlos I. Cabrera-Rodríguez, Mónica Moreno-González, Florence A. de Weerd, Vidhvath Viswanathan, Luuk A.M. van der Wielen, Adrie J.J. Straathof
Bioresource Technology 2017 Volume 237(Volume 237) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.biortech.2017.02.030
•Paper mill wastewater was treated with an anaerobic mixed culture fermentation.•Carboxylic acids were produced at a pH above their pKa.•Carboxylates salts were recovered using a strong anion exchange resin.•The resin is regenerated and esters were produced using CO2-expanded methanol.This paper describes a new option for integrated recovery and esterification of carboxylates produced by anaerobic digestion at a pH above the pKa. The carboxylates (acetate, propionate, butyrate, valerate and lactate) are recovered using a strong anion exchange resin in the bicarbonate form, and the resin is regenerated using a CO2-expanded alcohol technique, which allows for low chemicals consumption and direct esterification. Paper mill wastewater was used to study the effect of pH and the presence of other inorganic anions and cations on the adsorption and desorption with CO2-expanded methanol. Calcium, which is present in paper mill wastewater, can cause precipitation problems, especially at high pH. Esters yields ranged from 1.08 ± 0.04 mol methyl acetate/mol of acetatein to 0.57 ± 0.02 mol methyl valerate/mol of valeratein.Download high-res image (82KB)Download full-size image
Co-reporter:Camilo S. López-Garzón, Luuk A. M. van der Wielen and Adrie J. J. Straathof
RSC Advances 2016 vol. 6(Issue 5) pp:3823-3829
Publication Date(Web):17 Dec 2015
DOI:10.1039/C5RA17752A
Two culture broths, one containing succinate produced de novo by Corynebacter glutamicum and the other containing 2,5-furandicarboxylate produced by whole cell biotransformation of 5-(hydroxymethyl)furfural (HMF) by a recombinant Pseudomonas putida, were used for dimethyl ester production. For anion exchange, they were characterized for competing organic anions (i.e., other carboxylates) and inorganic anions (phosphate, sulfate and chloride), which affect capturing of the target dicarboxylate via sorption. For the analysis of the sorption process, independent multicomponent column experiments using mimicked mixtures of the respective target building blocks with organic anions, inorganic anions and actual fermentation broth were performed. In the case of succinate, breakthrough profiles and column capacities showed that α-ketoglutarate, malate and other fermentation impurities reduced sorption capacity. For 2,5-furandicarboxylate, the effect of impurities in sorption was less pronounced, with residual HMF eluting without any apparent ionic interaction. After sorption, upgrading via alkylation from mimicked and bio-based broth was successfully carried out, producing the respective succinate and 2,5-furandicarboxylate dimethyl esters. The yield towards dimethyl succinate was reduced from 0.98 to 0.66 mol ester per mol carboxylate due to the presence of fermentation impurities, which were also esterified in good yields. The final yield of dimethyl 2,5-furandicarboxylate ranged between 0.75 and 0.77 mol ester per mol carboxylate for both pure and raw bio-based sorbed furandicarboxylate. Esterification kinetics correlate well with the acidity of the carboxylates and impurities.
Co-reporter:Joana P. C. Pereira;Peter J. T. Verheijen
Applied Microbiology and Biotechnology 2016 Volume 100( Issue 21) pp:9069-9080
Publication Date(Web):2016 November
DOI:10.1007/s00253-016-7642-1
This paper describes the effect of several inhibiting components on three potential hosts for the bio-based production of methyl propionate, namely, wild-type Escherichia coli and Bacillus subtilis, and evolved Saccharomyces cerevisiae IMS0351. The inhibition by the lignocellulose-derived products 5-hydroxymethyl-2-furaldehyde, vanillin, and syringaldehyde and the fermentation products 2-butanol, 2-butanone, methyl propionate, and ethyl acetate has been assessed for these strains in defined medium. Multiple screenings were performed using small-scale cultures in both shake flasks and microtiter plates. Technical drawbacks revealed the limited applicability of the latter in this study. The microbial growth was characterized by means of a lag-time model, and the inhibitory thresholds were determined using product-inhibition models. The lignocellulose-derived products were found to be highly inhibitory, and none of the strains could grow in the presence of 2.0 g L−1 of product. From the fermentation products tested, methyl propionate had the most severe impact resulting in complete inhibition of all the strains when exposed to concentrations in the range of 12–18 g L−1. In general, S. cerevisiae and B. subtilis were comparatively more tolerant than E. coli to all the fermentation products, despite E. coli’s lower sensitivity towards vanillin. The results suggest that, overall, the strains investigated have good potential to be engineered and further established as hosts for the bio-based production of methyl esters.
Co-reporter:Carlos I. Cabrera-Rodríguez, Luuk A. M. van der Wielen, and Adrie J. J. Straathof
Industrial & Engineering Chemistry Research 2015 Volume 54(Issue 44) pp:10964-10973
Publication Date(Web):October 18, 2015
DOI:10.1021/acs.iecr.5b02911
Quaternary ammonium carboxylates (both ionic liquids and resins) can be used for formation of methyl carboxylate esters in an alkylation reaction with dimethyl carbonate (DMC). This reaction is pursued in the context of a low-waste process for recovery and upgrading of fermentative carboxylates. Byproducts, such as methanol, are produced during the alkylation reaction with DMC. A molar yield of methyl acetate on acetate of 0.84 and modest selectivity (0.54–0.95 mol of methyl acetate/mol of methanol) are obtained with an anion exchanger fully in the acetate form. Water and DMC concentrations have a strong effect on the yield and selectivity of the reaction. Model calculations indicate that an excess of 50 mol of DMCin/mol of acetatein in DMC is needed to achieve yields above 0.98 mol of methyl acetate/mol of acetatein, and water concentrations in the resin below 0.04 g of water/g of resin to achieve a selectivity above 1.1 mol of methyl acetate/mol of methanol. The explanation for the modest selectivity is the hydrolysis and absence of methylating activity of the methylcarbonate anion. This indicates that 1 mol of DMC is consumed for the alkylation of 1 mol of a monocarboxylate salt. The utilization of a low amount of DMC is critical, especially for low value products such as methyl acetate.
Co-reporter:Adrie J. J. Straathof
Chemical Reviews 2014 Volume 114(Issue 3) pp:1871
Publication Date(Web):August 29, 2013
DOI:10.1021/cr400309c
Co-reporter:Carol A. Roa Engel, Joop H. ter Horst, Mervin Pieterse, Luuk A. M. van der Wielen, and Adrie J. J. Straathof
Industrial & Engineering Chemistry Research 2013 Volume 52(Issue 27) pp:9454-9460
Publication Date(Web):June 12, 2013
DOI:10.1021/ie400794r
Fumaric acid is a dicarboxylic acid applied in food industry and in some polymers. Currently, its fermentative production from renewable resources is receiving much attention, and crystallization is used to recover it. To determine the window of operation for crystallization from multicomponent fermentation mixtures, the aqueous solubilities of fumaric acid and its sodium salts were investigated. For fumaric acid, sodium hydrogen fumarate, and sodium fumarate, solubilities and pH increased in this order because of increasing polarity and dissociation. A mathematical model was developed to predict crystal type and amount as function of temperature and pH. The effect of glucose (up to 3.0 mmol·mol–1) on the solubility can be neglected, but ethanol (1.0 mmol·mol–1) slightly increased the solubility of fumaric acid and significantly decreased the solubility of the sodium salts, because the aqueous solution becomes less polar upon ethanol addition but not upon glucose addition.
Co-reporter:Bianca N. M. van Leeuwen
Applied Microbiology and Biotechnology 2012 Volume 93( Issue 4) pp:1377-1387
Publication Date(Web):2012 February
DOI:10.1007/s00253-011-3853-7
Isobutene (2-methylpropene) is one of those chemicals for which bio-based production might replace the petrochemical production in the future. Currently, more than 10 million metric tons of isobutene are produced on a yearly basis. Even though bio-based production might also be achieved through chemocatalytic or thermochemical methods, this review focuses on fermentative routes from sugars. Although biological isobutene formation is known since the 1970s, extensive metabolic engineering is required to achieve economically viable yields and productivities. Two recent metabolic engineering developments may enable anaerobic production close to the theoretical stoichiometry of 1isobutene + 2CO2 + 2H2O per mol of glucose. One relies on the conversion of 3-hydroxyisovalerate to isobutene as a side activity of mevalonate diphosphate decarboxylase and the other on isobutanol dehydration as a side activity of engineered oleate hydratase. The latter resembles the fermentative production of isobutanol followed by isobutanol recovery and chemocatalytic dehydration. The advantage of a completely biological route is that not isobutanol, but instead gaseous isobutene is recovered from the fermenter together with CO2. The low aqueous solubility of isobutene might also minimize product toxicity to the microorganisms. Although developments are at their infancy, the potential of a large scale fermentative isobutene production process is assessed. The production costs estimate is 0.9 € kg−1, which is reasonably competitive. About 70% of the production costs will be due to the costs of lignocellulose hydrolysate, which seems to be a preferred feedstock.
Co-reporter:Rosario Médici;Pablo Domínguez de María;Linda G. Otten;Adrie J. J. Straathof
Advanced Synthesis & Catalysis 2011 Volume 353( Issue 13) pp:2369-2376
Publication Date(Web):
DOI:10.1002/adsc.201100386
Abstract
The development of sensitive and easy-to-apply high-throughput screening methods is a common need in modern biocatalysis. With these powerful analytical tools in hands, chemists can easily assess enzyme libraries to identify either novel biocatalysts or improved mutants. Within biocatalysis, amino acid decarboxylases are gaining an increased importance, with several diverse applications ranging from the synthesis of bio-commodities to medical applications (e.g., synthesis of enzyme inhibitors at the level of L-DOPA decarboxylase). Herein, an efficient and simple analytical method for high-throughput screening of amino acid decarboxylase activity is reported. The method is valid for the discrimination of a broad range of amino acid/amine pairs such as L-tyrosine/tyramine, L-DOPA/dopamine, 5-hydroxy-L-tryptophan/serotonin, L-histidine/histamine, L-serine/ethanolamine, L-tryptophan/tryptamine, L-glutamic acid/GABA, and L-alanine/ethylamine. It has proven its versatility by using pure substrates, mixtures, or enzymatic reactions, both coming either from commercial enzymes or derived from cell-free (crude) extracts. The limit of detection was 13 μM for ethanolamine in the presence of 50 mM L-serine, while z′ values were in the range 0.75–0.93, indicating the suitability for high-throughput screening.
Co-reporter:Arjan Oudshoorn;Marjolein C. F. M. Peters;Luuk A. M. van der Wielen ;Adrie J. J. Straathof
Journal of Chemical Technology and Biotechnology 2011 Volume 86( Issue 5) pp:714-718
Publication Date(Web):
DOI:10.1002/jctb.2577
Abstract
BACKGROUND: Fermentative production of 1-butanol yields dilute aqueous solutions. Recovery of the butanol from these solutions is most commonly performed by energy-intensive distillation. This work investigated the liquid-liquid (L-L) phase behavior of mixtures of butanol and water to explore the potential of using L-L phase separation as a recovery possibility for 1-butanol. The phase behavior is preferably influenced by compounds already present in the fermentation, such as carbohydrates and salts.
RESULTS: The L-L phase equilibria of butanol and water were determined in the presence of glucose, fructose, sucrose, NaCl, LiCl and CaCl2. The aqueous and organic phase split is more pronounced in the presence of salts than in the presence of carbohydrates. Demixing is achieved with about 0.3 kg salt kg−1 aqueous phase containing 40 g of butanol.
CONCLUSION: Operation of L-L based recovery using salts or carbohydrates requires extreme concentrations of those compounds. For feed material containing 40 g kg−1 butanol, the tested carbohydrates do not influence the phase equilibria sufficiently to allow butanol separation. Fermentative butanol concentrations up to 70 g kg−1 are required to create an effective L-L phase split. The remaining residual aqueous carbohydrate solution might be used as feed for a following fermentation. Copyright © 2011 Society of Chemical Industry
Co-reporter:Çağri Efe, Luuk A. M. van der Wielen and Adrie J. J. Straathof
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 4) pp:1837-1843
Publication Date(Web):January 5, 2010
DOI:10.1021/ie901110b
Initial studies were performed on succinic acid adsorption from aqueous solutions by zeolite powders. CVB-28014 (high-silica ZSM-5) showed higher equilibrium loadings (up to 0.16 g/g) than CBV-901 and CP811C-300, and was used for follow up studies. In the presence of Na+ counterions, the succinic acid adsorption decreased in parallel with the succinic acid dissociation, but the adsorbent also showed some affinity toward sodium hydrogensuccinate with selectivities in the range 10−20 toward succinic acid. The presence of acetic acid resulted in lower succinic acid loadings but the capacities remained sufficient for efficient recovery. The selectivity between succinic acid and acetic acid ranged from 1 to 6. Increasing the temperature to 70 °C reduced the equilibrium loadings, but in ethanol the succinic acid loadings showed a more significant drop. Therefore, regeneration might be achieved by using an adsorption-competitive solvent like ethanol. The current results suggest that this may lead to an attractive option for the recovery of succinic acid from fermentation media. Hydrophobic rather than ionic interactions are used, thus avoiding regeneration involving acid and base and the associated waste salt production.
Co-reporter:Maria C. Cuellar, Adrie J. J. Straathof, Emile J. A. X. van de Sandt, Joseph J. Heijnen and Luuk A. M. van der Wielen
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 2) pp:682-689
Publication Date(Web):November 20, 2009
DOI:10.1021/ie901007g
The production of the amino acid l-phenylalanine (Phe) by fermentation is in many cases limited by the tight regulation of the microbial pathway leading to Phe synthesis. One way of circumventing feedback repression is to remove the product from the vicinity of the micro-organism as soon as it is being formed. In the case of Phe, techniques like adsorption and extraction have been applied with this aim. In these processes, however, additional recovery steps are required in order to obtain the product as anhydrate crystals, which is its commercial form. In this work we evaluated conceptually the recovery of Phe anhydrate crystals during a fermentation process. The product recovery consisted of water removal by reverse osmosis, crystallization, and recycle of the mother liquor either to the fermenter, to the water removal unit or to both. By maintaining the Phe mass fraction in the fermenter at about 17 g kg−1 the fermentation productivity increased according to the calculations from 0.66 g kg−1 h−1, without product removal, to 1.07 g kg−1 h−1, with product removal, where about 70% of the produced Phe was directly recovered as anhydrate crystals. By means of a simplified economic model it was shown that the membranes required for cell retention and water removal have much more impact on the economic performance of the process than the consumption of raw materials, and therefore, the favored recycling option for the mother liquor is to the water removal unit.
Co-reporter:Çağri Efe, Mervin Pieterse, Jorge Gascon, Freek Kapteijn, Luuk A. M. van der Wielen and Adrie J. J. Straathof
Industrial & Engineering Chemistry Research 2010 Volume 49(Issue 8) pp:3794-3801
Publication Date(Web):March 10, 2010
DOI:10.1021/ie1000168
In adsorptive separation processes, regeneration of the adsorbent plays an important role. Depending on the type of product the regeneration strategy might differ from one process to another. In this study, the desorption of succinic acid from a high silica ZSM-5 adsorbent is studied, using displacement by an organic solvent or CO2, or temperature swing. According to a number of process criteria and solvent selection criteria, 2-butanone performed better than the other displacing agents studied. However, the subsequent regeneration step involved desorption of butanone, which proved to be difficult and required a temperature above the normal boiling point of water under elevated pressures. Such a temperature swing with hot water can also be applied for direct succinic acid desorption without intermediate displacement by butanone. A countercurrent continuous adsorption process was modeled to compare these options. Direct temperature swing using pressurized water at >100 °C proved to be more attractive to achieve a sustainable process.
Co-reporter:Arjan Oudshoorn, Luuk A. M. van der Wielen and Adrie J. J. Straathof
Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 15) pp:7325-7336
Publication Date(Web):June 24, 2009
DOI:10.1021/ie900537w
The microbial production of 1-butanol occurs in aqueous fermentation broth, with up to ∼20 g/L of product. Efficient recovery of butanol from this dilute aqueous phase determines, to a large extent, the efficiency of the production process. Starting from the thermodynamic (phase) properties of butanol and water systems, this paper presents a structured approach to determine the key characteristics of various butanol recovery methods. Analysis of reported separations, combined with fundamental phase properties, has resulted in both the characterization of the selectivity of recovery and estimations of the energy requirement during product recovery for a variety of recovery methods. Energy-efficient systems for the recovery of butanol from aqueous solution are pervaporation- and adsorption-based techniques. The applied method predicts the recovery energy requirement for both techniques to be <4 MJ/kg of butanol, which, on an energy basis, is similar to ∼10% of the internal combustion energy of butanol.
Co-reporter:Carol A. Roa Engel, Adrie J. J. Straathof, Walter M. van Gulik, Emile J. A. X. van de Sandt, Thom van der Does and Luuk A. M. van der Wielen
Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 9) pp:4352-4364
Publication Date(Web):April 6, 2009
DOI:10.1021/ie801335r
Integration of fermentation and downstream steps is required to improve the sustainability of industrial biotechnology processes. In this context, a new integrated process for β-lactam nuclei production is proposed, which has been theoretically investigated and conceptually designed. This process is an integration of fermentation and enzymatic deacylation of adipyl-7-aminodeacetoxycephalosporanic acid (adADCA) in one reactor producing 7-aminodeacetoxycephalosporanic acid (ADCA) directly from glucose. Although the deacylation equilibrium is unfavorable at the fermentation pH, it is pulled to completion because ADCA starts to crystallize and the liberated side chain, adipic acid (AA), is consumed by the fermentation. Therefore the integrated process requires much less AA than the nonintegrated process. In addition, the new process will lead to a reduction in number of downstream processing units, should avoid the use of acids and bases for pH shifts, and might lead to a reduction in waste salts production. A conceptual process was designed including an economic and technical analysis. The design goal was to produce 2000 tons/year of ADCA of 99% purity. Rigorous simulations were performed to evaluate different process options. Among the economic advantages of the new integrated process are 13.4% lower capital investments and 7.8% lower manufacturing costs. An analogous process for 6-aminopenicillanic acid (APA) is not feasible due to chemical degradation of this product.
Co-reporter:Maria C. Cuellar, Simone N. Herreilers, Adrie J. J. Straathof, Joseph J. Heijnen and Luuk A. M. van der Wielen
Industrial & Engineering Chemistry Research 2009 Volume 48(Issue 3) pp:1566-1573
Publication Date(Web):January 8, 2009
DOI:10.1021/ie8012659
Integration of crystallization and water removal using membrane technology is being used as a means to improve control over supersaturation generation and, consequently, to improve crystal quality. However, it is not clear yet how water removal, which has a limited window of operation, can be combined with crystallization in case of occurrence of several crystal forms (and, therefore, also a limited window of operation). In this work we evaluated the use of nanofiltration and reverse osmosis for water removal to achieve selective crystallization of l-phenylalanine anhydrate from aqueous solution. Water removal and crystallization were first studied separately, and models were used to define the limits of operation for the coupled system so that the target crystal form and production rate could be achieved. A narrow window of operation was obtained, and it was shown that practical implementation can be difficult due to operation near the limits of the window of operation. Possibilities for widening the window of operation are briefly discussed.
Co-reporter:Carol A. Roa Engel;Adrie J. J. Straathof
Applied Microbiology and Biotechnology 2008 Volume 78( Issue 3) pp:379-389
Publication Date(Web):2008 March
DOI:10.1007/s00253-007-1341-x
The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical process yields 112% w/w fumaric acid from maleic anhydride and the fermentation process yields only 85% w/w from glucose, the latter raw material is three times cheaper. Besides, the fermentation fixes CO2. Production of fumaric acid by Rhizopus species and the involved metabolic pathways are reviewed. Submerged fermentation systems coupled with product recovery techniques seem to have achieved economically attractive yields and productivities. Future prospects for improvement of fumaric acid production include metabolic engineering approaches to achieve low pH fermentations.
Co-reporter:Camilo S. López-Garzón, Adrie J.J. Straathof
Biotechnology Advances (September–October 2014) Volume 32(Issue 5) pp:873-904
Publication Date(Web):September–October 2014
DOI:10.1016/j.biotechadv.2014.04.002
Co-reporter:Carol A. Roa Engel, Walter M. van Gulik, Leonie Marang, Luuk A.M. van der Wielen, Adrie J.J. Straathof
Enzyme and Microbial Technology (5 January 2011) Volume 48(Issue 1) pp:39-47
Publication Date(Web):5 January 2011
DOI:10.1016/j.enzmictec.2010.09.001
Dicarboxylic acids that are produced from renewable resources are becoming attractive building blocks for the polymers industry. In this respect, fumaric acid is very interesting. Its low aqueous solubility facilitates product recovery. To avoid excessive waste salt production during downstream processing, a low pH for fumaric acid fermentation will be beneficial. Studying the influence of pH, working volume and shaking frequency on cell cultivation helped us to identify the best conditions to obtain appropriate pellet morphologies of a wild type strain of Rhizopus oryzae. Using these pellets, the effects of pH and CO2 addition were studied to determine the best conditions to produce fumaric acid in batch fermentations under nitrogen-limited conditions with glucose as carbon source. Decreasing either the fermentation pH below 5 or increasing the CO2 content of the inlet air above 10% was unfavourable for the cell-specific productivity, fumaric acid yield, and fumaric acid titer. However, switching off the pH control late in the batch phase did not affect these performance parameters and allowed achieving pH of 3.6. A concentration of 20 g L−1 of fumaric acid was obtained at pH 3.6 while the average cell mass specific productivity and fumaric acid yield were the same as at pH 5.0. Consequently, relatively modest amounts of inorganic base were required for pH control, while recovery of the acid should be relatively easy at pH 3.6.
Co-reporter:Maria C. Cuellar, Tiemen W. Zijlmans, Adrie J.J. Straathof, Joseph J. Heijnen, Luuk A.M. van der Wielen
Biochemical Engineering Journal (15 May 2009) Volume 44(Issues 2–3) pp:280-288
Publication Date(Web):15 May 2009
DOI:10.1016/j.bej.2009.01.006
Co-reporter:Arjan Oudshoorn, Luuk A.M. van der Wielen, Adrie J.J. Straathof
Biochemical Engineering Journal (15 December 2009) Volume 48(Issue 1) pp:99-103
Publication Date(Web):15 December 2009
DOI:10.1016/j.bej.2009.08.014
Co-reporter:Marija Saric, Luuk A.M. van der Wielen, Adrie J.J. Straathof
Chemical Engineering Science (1 February 2011) Volume 66(Issue 3) pp:510-518
Publication Date(Web):1 February 2011
DOI:10.1016/j.ces.2010.11.020
Irreversible reactions are being applied in enzymatic kinetic resolution to obtain enantiomerically pure compounds from racemic mixtures. Using model calculations for situations without mass transfer limitation, we show that reversible reactions might also be useful for enzymatic kinetic resolution, provided that countercurrent systems are used rather than batch or cocurrent systems. The required reaction time or enzyme amount in a countercurrent system is much lower than in an analogous cocurrent system or its batch equivalent. More importantly, often the calculated yield and enantiomeric excess are better in countercurrent systems. Racemization can also be favorably used in countercurrent systems. Consequently, to achieve with a reversible reaction a particular enantiomeric excess and yield, a countercurrent system needs less dilution or activated co-reactant and less enantioselective enzyme than a cocurrent system.
