Process limitations in a whole-cell catalysed oxidation: Sensitivity analysis

Biocatalytic oxidation processes have to date presented major problems for scale-up, in part due to the complexity of the number of process variables. In this paper we have analysed the key limitations in such processes using the Baeyer-Villiger monooxygenase catalysed synthesis of optically pure lactones as an illustrative example. Limitations in product concentration, catalyst longevity and reaction rate were quantified and their effect on previously defined process metrics identified. Of particular interest is the way these metrics change with catalyst concentration. Using this assessment, the sensitivity of the metrics to potential changes to process and catalyst were analysed. We believe such an analysis is of general use to guide development efforts for a given biocatalytic reaction. (c) 2006 Elsevier Ltd. All rights reserved

Biocatalysts for selective introduction of oxygen

Three types of oxygenase biocatalysts are treated in detail in this review: the non-haem iron alkene mono-oxygenases, the haem and vanadium haloperoxidases, and flavin-based Baeyer-Villiger mono-oxygenases. Other oxygenases are briefly included for comparison. Characteristics of the biocatalysts are presented, and the scope and limitations concerning their applicability for the selective introduction of oxygen are discussed. Key issues include catalytic activity, productivity, cloning and expression, as well as process engineering aspects. Various bottlenecks are identified for the different biocatalysts and measures to increase the number of oxygenase reactions in practical use are discussed