A mathematical model for glucose oxidase kinetics, including inhibitory, deactivant and diffusional effects, and their interactions

Activity of carbohydrate oxidases as influenced by wheat flour dough components

“…The acidification of the reaction medium can not explain in itself the observed inhibitory effect of gluconolactone on the oxidases' activities since, at the concentration tested, the decrease in pH of a gluconolactone solution was below 0.1 pH unit one hour after its preparation. Gluconic acid, the hydrolysis product of gluconolactone, can act as a competitive inhibitor to COXMn as was reported for A. niger GOX (Gibson, Swoboda, & Massey, 1964;Mirón, González, Vázquez, Pastrana, & Murado, 2004). Polarography measurements showed that COXMn (0.64 mg in polarograph cell) had no catalase activity towards 1 mol L À1 H 2 O 2 at pH 5.6 and 30°C, contrary to GOX which had a strong activity.…”

“…Similarly, Nordkvist et al (2007) concluded that the produced hydrogen peroxide concentration was not sufficient to inhibit or deactivate COXMn. In the case of GOX supplied by Novozymes, its strong catalase activity can prevent the reported inhibitory effect of hydrogen peroxide (Bao, Furumoto, Yoshimoto, Fukunaga, & Nakao, 2003;Kleppe, 1966;Mirón et al, 2004). In bread making, the contribution of COXMn and GOX in the formation of networks depends on the hydrogen peroxide that they produce and that is used by peroxidases.…”

Effect of hydrodynamics on kinetics of gluconic acid enzymatic production in bubble column reactor

“…Due to the fact that hydrogen peroxide has the inhibition effect on GOD and reaction rate [9,[21][22][23], it was necessary to prevent its production by adding sufficient amount of catalase, thus, no free hydrogen peroxide was observed. In order to determine the reaction rate, the concentration of gluconic acid was measured by titration with NaOH.…”

On-line estimation in a distributed parameter bioreactor: Application to the gluconic acid production

“…Preliminary experiments [19,20] show that the peroxide is quickly consumed to produce water and oxygen so reaction (6d) is not limiting. This leads to the following simplified mechanism representative of the behavior of the system:…”

“…Microorganisms also produce catalasa (CAT ) that breaks the hydrogen peroxide (H 2 O 2 ). This suggests the following reaction mechanism [21,19,20]:…”