Solid‐Gas Reactors A Comparison between the Horse Liver and the Thermostable <i>Sulfolobus solfataricus</i> ADH

Pulvin, Sylviane; Parvaresh, Firooze; Thomas, Daniel; Legoy, Marie‐Dominique

doi:10.1111/j.1749-6632.1988.tb25870.x

Cited by 34 publications

(10 citation statements)

References 5 publications

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“…Only a few studies were conducted using ADH enzymes such as yeast alcohol dehydrogenase from Saccharomyces cerevisiae (YADH), horse liver alcohol dehydrogenase (HLADH), Sulfolobus solfataricus alcohol dehydrogenase (SSADH), and Lactobacillus brevis alcohol dehydrogenase (LBADH) as either whole cell or isolated enzyme (6, 8, 13). Since gas‐phase reactions require elevated temperatures, Pulvin et al (14) compared the thermostability of mesophilic HLADH with that of the thermophilic SSADH in gas‐phase reaction.…”

Section: Introductionmentioning

confidence: 99%

Study on Mesophilic and Thermophilic Alcohol Dehydrogenases in Gas-Phase Reaction

Trivedi¹,

Spieß²,

Daußmann³

et al. 2006

Biotechnol. Prog.

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The initial reaction rate and the thermostability of the mesophilic alcohol dehydrogenase (ADH) from Lactobacillus brevis (LBADH), and the thermophilic ADH from Thermoanaerobacter sp. (ADH T) in gas-phase reaction were compared. The effects of water activity, cofactor-to-protein molar ratio, and reaction temperature on the reduction of acetophenone to 1-phenylethanol were studied. An optimal water activity of 0.55 in terms of productivity was found for both ADHs. The cofactor-to-protein molar ratio was chosen slightly higher than equimolar to increase both activity and thermostability. An excellent optimal productivity of 1,000 g x L(-1) x d(-1) for LBADH and 600 g x L(-1) x d(-1)for ADH T was found at 60 degrees C, while the highest total turnover numbers with respect to the enzyme were achieved at 30 degrees C and amounted to 4.2 million for LBADH and 1.7 million for ADH T, respectively. Interestingly, the ADH from the mesophilic L. brevisshowed the higher thermostability in the nonconventional medium gas phase.

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Section: Introductionmentioning

confidence: 99%

Study on Mesophilic and Thermophilic Alcohol Dehydrogenases in Gas-Phase Reaction

Trivedi¹,

Spieß²,

Daußmann³

et al. 2006

Biotechnol. Prog.

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“…In the case of gas/solid catalysis with lipases, several days of continuous reactor operation at temperatures up to 100°C were achieved (16). Until today, however, only a few examples were known, in which alcohol dehydrogenases were used to catalyze gas-phase reactions (1,8,(22)(23)(24)(25). Besides being labile enzymes, alcohol dehydrogenases require a nicotinamide cofactor NAD(P), which is expensive and sensitive to temperature (26).…”

Section: Introductionmentioning

confidence: 99%

Optimization of Enzymatic Gas-Phase Reactions by Increasing the Long-Term Stability of the Catalyst

et al. 2004

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Enzymatic gas-phase reactions are usually performed in continuous reactors, and thus very stable and active catalysts are required to perform such transformations on cost-effective levels. The present work is concerned with the reduction of gaseous acetophenone to enantiomerically pure (R)-1-phenylethanol catalyzed by solid alcohol dehydrogenase from Lactobacillus brevis (LBADH), immobilized onto glass beads. Initially, the catalyst preparation displayed a half-life of 1 day under reaction conditions at 40 degrees C and at a water activity of 0.5. It was shown that the observed decrease in activity is due to a degradation of the enzyme itself (LBADH) and not of the co-immobilized cofactor NADP. By the addition of sucrose to the cell extract before immobilization of the enzyme, the half-life of the catalyst preparation (at 40 degrees C) was increased 40 times. The stabilized catalyst preparation was employed in a continuous gas-phase reactor at different temperatures (25-60 degrees C). At 50 degrees C, a space-time yield of 107 g/L/d was achieved within the first 80 h of continuous reaction.

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“…Commercially available lipases (triacyl glycerol hydrolase EC 3.1.1.3) were used for the synthesis of flavor esters in nearly anhydrous organic solvent [6][7][8][9][10][11]. Because this has some problems with respect to the product recovery [12] and mass transfer of reactants [13], the transformation of gaseous reactants by dehydrated ''dry'' enzyme is preferred for those situations in which the reactant is gaseous or can be vaporized [14][15][16][17][18][19]. Although little gas phase ester synthesis occurred with C. rugosa [20] when incubated in ethanol-and acetic acid-containing vapor at 30°C and humidities from 56% to 92%, the synthesis of ethyl acetate from ethanol and acetic acid in the gas phase was studied because this can be extended to other flavor esters (such as isopropyl and isobutyl acetate, ethyl propionate and butyrate) synthesis in the gas phase as shown in organic solvents).…”

Section: Introductionmentioning

confidence: 99%

Gas phase ethyl acetate production in a batch bioreactor

Hwang¹,

Park

1997

Bioprocess Engineering

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Gas phase ethyl acetate production was studied using a porcine pancreatic lipase powder. It was observed that gaseous ethyl acetate was produced from gaseous ethanol and acetic acid. Accordingly, the effects of amount of lipase powder, gaseous ethanol and acetic acid concentrations, and reaction temperature on the performance of a batch bioreactor were investigated. Apparent Michaelis-Menten constant of ethanol was 0.163 [ M] and there was no inhibition by ethanol over the range investigated. As acetic acid concentration increased, ethyl acetate production increased to a maximum, then decreased, thus suggesting the inhibition effects by acetic acid. Over the reaction temperature of 25-55°C, activation energy was calculated as 3.93 kcal/gmol and initial reaction rate was obtained as follows: r 75.7 exp()1975.7/T) [ M/mg of lipase/hr]

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Solid‐Gas Reactors A Comparison between the Horse Liver and the Thermostable Sulfolobus solfataricus ADH

Cited by 34 publications

References 5 publications

Study on Mesophilic and Thermophilic Alcohol Dehydrogenases in Gas-Phase Reaction

Study on Mesophilic and Thermophilic Alcohol Dehydrogenases in Gas-Phase Reaction

Optimization of Enzymatic Gas-Phase Reactions by Increasing the Long-Term Stability of the Catalyst

Gas phase ethyl acetate production in a batch bioreactor

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