A new enzymatic microdetermination procedure for ethanol with particulate alcohol dehydrogenase from acetic acid bacteria.

Abstract

A new enzymatic method for microdetermination of ethanol has been established with particulate alcohol dehydrogenase from acetic acid bacteria and applied to the practical purposes. The enzyme had an optimum pH for ethanol oxidation at a fairly acidic region. Trace amounts of ethanol could be assayed by measuring the initial reaction rate as successful as by reading the end point of the reaction.Some advantages in using this enzyme for ethanol determination were pointed out comparing with NAD-linked alcohol dehydrogenase from yeast or horse liver. Impurity in the enzyme preparations, stability of reagents and coexistence of other substances in the assay mixture were not as critical as in NAD-linked enzyme. Acidic samples could also be directly determined for ethanol without preadjustment of sample pH.

D-fructose dehydrogenase of Gluconobacter industrius: purification, characterization, and application to enzymatic microdetermination of D-fructose

“…The result indicates that the D-fructose dehydrogenase was present as a monomer in the presence of 1% Triton X-100, and that the molecular weight of this enzyme, 151,000, was nearly equal to that of yeast alcohol dehydrogenase, a result in good agreement with the 2 3 4 Volume (ml) FIG. 6. Sucrose density gradient centriftgation in the presence and absence of Triton X-100.…”

Intracellular ethanol — accumulation and exit from yeast and other cells

“…In the first of the direct injection techniques, cells taken directly from fermentation are centrifuged, washed with distilled water, recentrifuged and then injected into the gas chromatograph [8,26,27,[40][41]. Excessively high values are generally not obtained by this method, however, the highest apparent concentrations are obtained for the fastest growing cells [40,41]. This observation is significant since this technique assumes that the permeability of ethanol is low and hence washing with distilled water is assumed not to remove any ethanol.…”

L-Erythrulose Production by Oxidative Fermentation is Catalyzed by PQQ-Containing Membrane-bound Dehydrogenase

“…It was obvious that pH of the culture broth was decreased from 6.5 to 4.0-3.5 after 24-36 h of cultivation, suggesting that this oxidative fermentation had taken place by the action of membrane-bound dehydrogenase of the organism of which the optimum pH for oxidation reaction is shown to be in the acidic region. 2,7,[12][13][14][15][16][17][18][19][20][21] It appeared that the optimal production of L-erythrulose at higher temperatures was better than those at lower temperatures. The oxidation product from mesoerythritol formed by the action of Gluconobacter is based on the fact that this tetritol has the erythro form of two secondary hydroxyl groups adjacent to the primary alcohol moeity.…”