Polysaccharide-layered double hydroxide–aldolase biohybrid beads for biocatalysed CC bond formation.

This study describes the design a novel microbioreactor for the biocatalysed asymmetric synthesis of polyhydroxylated compounds. The bioreactor was elaborated by a hierarchical assembly of a recombinant fructose-6-phosphate aldolase (FSA wt ), layered double hydroxides (LDH) nanoplatelets and polysaccharide beads. Various polysaccharides were tested to encapsulate FSA wt and pre-immobilised FSA wt in LDH (FSA wt @Mg 2 Al-LDH). ι-Carrageenan appears as the most suitable candidate to prepare biohybrid beads. The retained activities in ι-carrageenan beads were measured for both free FSA wt and immobilised FSA wt revealing a 3 fold higher activity in favour of the pre-immobilised FSA. This result was probably due to a positive interaction between the negatively charged polysaccharide and the positively charged LDH layers. The catalytic activity, the recyclability and the storage of the beads were studied in addition to the leakage of FSA wt activity from beads. Nanostructuration of both FSA wt /ι-carr and FSA wt @Mg 2 Al-LDH/ι-carr was investigated by structural and textural characterization techniques. [ABSTRACT FROM AUTHOR]