Review Article Enzymes in Non-Conventional Phases

Ballesteros, Antonio; Bornscheuer, Uwe T.; Capewell, A.; Combes, Didier; Condoret, Jean‐Stéphane; Koenig, Kerstin; Kolisis, Fragiskos N.; Marty, Alain; Menge, Ulrich; Scheper, Thomas; Stamatis, Haralambos; Xenakis, Aris

doi:10.3109/10242429509040103

Cited by 100 publications

(49 citation statements)

References 130 publications

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“…The reaction rates observed with AOT MBGs were two to five times higher than these observed with surfactant free MBGs, while the conversion yields observed with all MBGs used were high. It is well known that the catalytic behavior of the enzymes in various microemulsion systems depends strongly on the structure and size of microdroplets [5,18,19], while the structure of the microdroplets depends on the nature and/or the presence of surfactant molecules [4,5,12]. Therefore, the difference on the reaction rates observed between AOT and surfactant free MBGs could be attributed to the effect of the different structure of the microdroplets on the enzyme catalytic behavior.…”

Section: Biocatalysis With Surfactant Free Microemulsion-based Organomentioning

confidence: 99%

“…[1][2][3][4]. These include: (a) macroheterogeneous biphasic systems such as liquid-liquid systems composed of a water-immiscible organic solvent and water; nearly anhydrous systems where the enzyme is usually suspended as a powder or in an immobilized form adsorbed onto a suitable carrier in organic solvents, ionic liquids or supercritical fluids and (b) microheterogeneous systems such as different types of water-in-oil (w/o) microemulsions or reverse micelles.…”

Section: Introductionmentioning

confidence: 99%

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Lipase biocatalytic processes in surfactant free microemulsion-like ternary systems and related organogels

Zoumpanioti

Karali

Xenakis

et al. 2006

Enzyme and Microbial Technology

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Section: Biocatalysis With Surfactant Free Microemulsion-based Organomentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Lipase biocatalytic processes in surfactant free microemulsion-like ternary systems and related organogels

Zoumpanioti

Karali

Xenakis

et al. 2006

Enzyme and Microbial Technology

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“…In the field of catalysis, the use of enzymes in organic synthesis and in non-conventional solvents has become an interesting alternative to conventional chemical methods [3,4]. One of the most intensively studied methods has been the technique of solubilizing enzymes in hydrated reverse micelles or water-in-oil microemulsions where they may retain their catalytic ability.…”

Section: Introductionmentioning

confidence: 99%

Biocatalysis using lipase encapsulated in microemulsion-based organogels in supercritical carbon dioxide

Blattner

Zoumpanioti

Kröner

et al. 2006

The Journal of Supercritical Fluids

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Lipases from Candida antarctica and Mucor miehei were encapsulated in lecithin water-in-oil (w/o) microemulsion-based organogels (MBG). These gels were formulated with either hydroxypropylmethyl cellulose (HPMC) or gelatin. The esterification of lauric acid and 1-propanol catalyzed by these MBGs was examined in supercritical carbon dioxide (scCO 2 ; 35• C, 110 bar) as solvent for the substrates. The results were compared to those obtained with the reference substrate solvent isooctane. It turned out that the initial rates of this model reaction in scCO 2 were higher than those observed in the reference system. Various parameters affecting the biocatalysis such as pressure, alcohol and acid chain length, and gel composition were investigated. Kinetic studies showed that the ester synthesis catalyzed by the immobilized C. antarctica lipase occurs via a Ping Pong Bi Bi mechanism in which only inhibition by excess of alcohol was identified. Values of all kinetic parameters were determined. In addition, experiments on the reusability of these gels in scCO 2 were carried out and the state of water within the organogel was examined with the help of differential scanning calorimetry. The present study shows that biocatalysis using MBGs in scCO 2 is a promising alternative to other bioconversion processes.

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“…These observations indicate that an improved enzymatic process might be developed if it could maintain relatively low concentrations of benzaldehyde in an aqueous phase while removing the PAC and related byproducts into an associated organic phase. The containment of high concentrations of one or more toxic substrates in the organic phase, as well as the continuous extraction of product/byproducts into this phase, away from the enzyme in the aqueous phase, can protect the biocatalyst from both potential inhibition and inactivation (Ballesteros et al, 1995;Bauer et al, 1999;Biselli et al, 1995;Husken et al, 2001). …”

Section: Introductionmentioning

confidence: 99%

(R)‐phenylacetylcarbinol production in aqueous/organic two‐phase systems using partially purified pyruvate decarboxylase from Candida utilis

Sandford

Breuer

Hauer

et al. 2005

Biotech & Bioengineering

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Aqueous/organic two-phase systems have been evaluated for enhanced production of (R)-phenylacetylcarbinol (PAC) from pyruvate and benzaldehyde using partially purified pyruvate decarboxylase (PDC) from Candida utilis. In a solvent screen, octanol was identified as the most suitable solvent for PAC production in the two-phase system in comparison to butanol, pentanol, nonanol, hexane, heptane, octane, nonane, dodecane, methylcyclohexane, methyl tert butyl ether, and toluene. The high partitioning coefficient of the toxic substrate benzaldehyde in octanol allowed delivery of large amounts of benzaldehyde into the aqueous phase at a concentration less than 50 mM. PDC catalyzed the biotransformation of benzaldehyde and pyruvate to PAC in the aqueous phase, and continuous extraction of PAC and byproducts acetoin and acetaldehyde into the octanol phase further minimized enzyme inactivation, and inhibition due to acetaldehyde. For the rapidly stirred two-phase system with a 1:1 phase ratio and 8.5 U/mL carboligase activity, 937 mM (141 g/L) PAC was produced in the octanol phase in 49 h with an additional 127 mM (19 g/L) in the aqueous phase. Similar concentrations of PAC could be produced in the slowly stirred phase separated system at this enzyme level, although at a much slower rate. However at lower enzyme concentration very high specific PAC production (128 mg PAC/U carboligase at 0.9 U/mL) was achieved in the phase separated system, while still reaching final PAC levels of 102 g/L in octanol and 13 g/L in the aqueous phase. By comparison with previously published data by our group for a benzaldehyde emulsion system without octanol (50 g/L PAC, 6 mg PAC/U carboligase), significantly higher PAC concentrations and specific PAC production can be achieved in an octanol/aqueous two-phase system.

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Review Article Enzymes in Non-Conventional Phases

Cited by 100 publications

References 130 publications

Lipase biocatalytic processes in surfactant free microemulsion-like ternary systems and related organogels

Lipase biocatalytic processes in surfactant free microemulsion-like ternary systems and related organogels

Biocatalysis using lipase encapsulated in microemulsion-based organogels in supercritical carbon dioxide

(R)‐phenylacetylcarbinol production in aqueous/organic two‐phase systems using partially purified pyruvate decarboxylase from Candida utilis

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