engleski

Synthesis of valuable building block with immobilized biocatalyst in rotating bed reactor

Halohydrin dehalogenases (HHDHs) are industrially important bacterial enzymes that belong to the group of lyases. On account on their activity, stability, β-regioselectivity and (R)- enantioselectivity, HHDHs can be used in the synthesis of optically active epoxides and β- substituted alcohols. Industrial applicability of biocatalysts increases with their stability and reusability, both of which can be improved with the use of different immobilization methods. Some of the most common methods of enzyme immobilization include covalent binding, adsorption, ionic binding, encapsulation, and cross-linking. Apart from enzymes, it is also possible to immobilize whole cells. The method of encapsulating whole cells in alginate beads is a cheap and simple method that enables the use of mild process conditions. Calcium alginate is one of the most commonly used carriers for the immobilization of whole cells. This method of encapsulation has several advantages, good biocompatibility, low cost, it is easily available and simple to prepare. In this work, recombinant Escherichia coli cells harboring HheC-ISM4 variant were immobilized in alginate beads and employed in rotating bed reactor (RBR) for the synthesis of (S)-2-(4-fluorophenyl)-3-hydroxypropanenitrile, valuable fluorinated building block for uses in fine chemicals industry. Given synthesis resulted in a high product yield and high optical purity of the product. The advantages of the RBR reactor over traditional batch reactor include enhancement of mass transfer, which often represents limitation in immobilized whole-cell synthesis, together with extremely simple recycling of the biocatalyst and its reuse in subsequent reactions.

Halohydrin dehalogenase ; Fluorinated building blocks ; Immobilized biocatalyst ; Rotating bed reactor

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