Kinetic modeling of a bi-enzymatic system for efficient conversion of lactose to lactobionic acid

Wouter Van, Aditya Bhagwat, Roland Ludwig, Jo Dewulf, Dietmar Haltrich, Herman Van Langenhove

Research output: Contribution to journalArticle

34 Citations (Scopus)


A model has been developed to describe the interaction between two enzymes and an intermediary redox mediator. In this bi-enzymatic process, the enzyme cellobiose dehydrogenase oxidizes lactose at the C-1 position of the reducing sugar moiety to lactobionolactone, which spontaneously hydrolyzes to lactobionic acid. 2,20 Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt is used as electron acceptor and is continuously regenerated by laccase. Oxygen is the terminal electron acceptor and is fully reduced to water by laccase, a coppercontaining oxidase. Oxygen is added to the system by means of bubble-free oxygenation. Using the model, the productivity of the process is investigated by simultaneous solution of the rate equations for varying enzyme quantities and redox mediator concentrations, solved with the aid of a numerical solution. The isocharts developed in this work provide an easy-to-use graphical tool to determine optimal process conditions. The model allows the optimization of the employed activities of the two enzymes and the redox mediator concentration for a given overall oxygen mass transfer coefficient by using the isocharts. Model predictions are well in agreement with the experimental data.

Original languageEnglish
Pages (from-to)1475-1482
Number of pages8
JournalBiotechnology and Bioengineering
Issue number5
Publication statusPublished - 1 Apr 2009
Externally publishedYes



  • Biotransformations
  • Carbohydrates
  • Cellobiose dehydrogenase
  • Kinetic modeling
  • Laccase

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

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