Glucoseoxidase from Aspergillus niger in reverse micelles: pH and wo dependence.
The well known enzymatic method for the determination of glucose in aqueous solution with the system glucose oxidase/peroxidase/o-dianisidine was modified in a way that enables the quantitative determination of glucose in various reverse micellar systems. For instance in the 0.1 M sodium-bis-(2-ethylhexyl)-sulfosuccinate/n-octane system the useable glucose measuring range is between 10 and 70 micrograms glucose per 3 ml micellar solution. Investigations concerning the influence of the pH-value and the wo-value on the enzyme activity of glucose oxidase in the system 0.1 M sodium-bis-(2-ethylhexyl) sulfosuccinate/n-octane led to a shift of the pH-optimum from pH 5.5-6.0 in aqueous solution, to pH 4.0, in reverse micellar solution. The bell-shaped wo-dependence of the enzyme activity, typical for many other enzymes, was not found for glucose oxidase at pH 4.0, and was less clearly visible at the other investigated pH-values with an optimum at wo = 5.6.
Raabe
E
E
Institute of Foodchemistry, Technical University Berlin, Germany.
Kroh
L
L
Vogel
J
J
D001234:Aspergillus niger / Q000201:enzymology*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004143:Dioctyl Sulfosuccinic Acid; D005947:Glucose / Q000032:analysis*; D005949:Glucose Oxidase / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008722:Methods; D008823:Micelles; D009795:Octanes; D009994:Osmolar Concentration; D013501:Surface-Active Agents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D008823:Micelles; D009795:Octanes; D013501:Surface-Active Agents; D014867:Water; D004143:Dioctyl Sulfosuccinic Acid; D005949:Glucose Oxidase; D005947:Glucose