Laccase improvement in submerged cultivation: induced production and kinetic modelling

Improvement of laccase production by Trametes versicolor was made by employing different operational strategies. In the cell growth medium, various glucose concentrations were compared for improving laccase production. A clear and significant stimulation of enzyme production under carbon limitation was obtained. Copper, 2,S-xylidine, and a phenolic mixture were also used as laccase inducers. A cooperative effect between the inducers on laccase production was identified. Mixtures of inducers produced higher laccase activities, reaching values of 5500 U dm(-3). Further productivity enhancement can be obtained using the inducers along with the carbon limitation strategy. It is shown that low laccase concentrations are obtained by a primary metabolism of T versicolor, and that phenolic compounds and carbon limitation induce a secondary metabolism, providing higher laccase concentrations. A mathematical model for laccase production based on a direct experimental measure of biomass, along with substrate consumption and enzymatic activity over time is proposed for non-homogeneous fermentations of T versicolor. (c) 2005 Society of Chemical Industry.