Transketolase catalysed upgrading of l -arabinose: the one-step stereoselective synthesis of l -gluco-heptulose

Conversion of biomass using biocatalysis is likely to become a technology that contributes significantly to the future production of chemical building blocks, materials and transport fuels. Here the synthesis of a value-added chemical from l-arabinose, a major component of the carbohydrates in sugar beet pulp (SBP), in a concise and sustainable manner has been investigated. Biocatalytic conversions using transketolase variants have been developed for the efficient, scalable synthesis of a rare naturally occurring ketoheptose, l-gluco-heptulose, from l-arabinose. New active E. coli TK mutants that readily accept l-arabinose were identified using a versatile colorimetric screening assay and the reaction was performed on a preparative scale.