Background: Invert sugar have a great impact in food and pharmaceutical industries. This paper describes scaling up batch conditions for sucrose inversion catalyzed by the recombinant Pichia pastoris BfrA4X whole cells, expressing Thermotoga maritima invertase entrapped in calcium alginate beads. By the first time we describe the application of a kinetic model to predict the fractional conversion expected during sucrose hydrolysis reaction in both, a model and a prototype bioreactor, with 0.5 and 5 L working volume, respectively.

Results: Different scaled up criteria used to operate the 0.5 L bioreactor like dosage of immobilized biocatalyst and stirring speed were analyzed. To explore the invert sugar large-scale production after model inversion studies, a 5-L scaled-up reaction system was performed in a 7-L stirred reactor. Both scaled up criteria like immobilized biocatalyst dosage and stirring speed were analyzed in each type of bioreactors and gathered data were useful to guaranty an efficient scaled up of this biocatalyst.

Conclusions: To date, there is not enough information to describe the large scale production of invert sugar by using different scaled up criteria like dosage of immobilized biocatalyst and stirring speed influence in mass transfer. This information constitutes a valuable tool to successfully carry out this type of high scale operation useful for industrial purposes.