Use of the glucose oxidase system to measure oxygen transfer rates

Abstract

SummaryThis investigation used the glucose oxidase system to simulate oxygen transfer rate in fermentation broths. It was demonstrated that the fungal preparation contained sufficient lactonase activity 80 that D-glucono-8-lactone did not accumulate and that the rate of production of gluconic acid was proportional to the oxygen uptake rate. Enzyme concentrations of 1.5-2 g/l were found adequate to determine oxygen absorption rates in shake flasks while maintaining the dissolved oxygen concentration of low levels. The apparent Michaelis constant for oxygen, K,(Oz), was found to be 27% saturation with air; this value along with experimentally determined uptake rates could be used to calculate dissolved oxygen concentration in lieu of using a dissolved oxygen probe. Enzyme concentrations of 5 g/l were sufficient to give linear acid production and low dissolved oxygen concentrations in a bench-scale fermenter with no foaming or enzyme deactivation. The method is considered more valid and easier to employ than previously utilized techniques such as sulfite oxidation. Extension of the system to evaluating aeration effectiveness and scaleup of fermentation equipment is discussed.

Kinetics of the conversion of glucose to gluconic acid by Pseudomonas ovalis

“…Assuming the concentration of the enzyme-sugar complex is constant in the pseudo-steady state, then (9) For resting cells the total enzyme concentration is a constant: Equation (15) predicts that if K , is large then the rate of acid production will be independent of the dissolved oxygen concentration above a value characteristic of the kinetic constants of the enzyme system. This concentration may be identified with the classical "critical" oxygen concentration.…”

Enzyme production ofd-gluconic acid and glucose oxidase: successful tales of cascade reactions

“…For example, in well-established research, glucose oxidase was used to simulate the oxygen transfer rate in fermentation broths. 190 If there is enough lactonase activity in the fungus, the D-gluconic acid production rate is proportional to the oxygen uptake rate. Glucose oxidase was immobilized on a…”

Physiologische und biochemische Aspekte industrieller Fermentationsprozesse

“…Die industrielle Glukonsäureproduktion wird mit Aspergillus niger durchgeführt [Martin, 1963]. Die pri märe enzymatische Reaktion ist die Oxydation der Glukose zu Glukonsäure über D-Glucono-^-laclon als Intermediärprodukt [Hsieh et al, 1969] [Schlegel, 1969]. An hand der alkoholischen Gärung lässt sich die Möglichkeit der Be einflussung einer Produktbildung über extrazelluläre Massnahmen sehr schön illustrieren.…”