Efficient Catalytic Synthesis of Allitol in Recombinant Escherichia coli

Abstract:

[Objective] This study aims to enhanced the conversion efficiency of allitol through biocatalytic methods. [Methods] The ribulose dehydrogenase (RDH) genes rdh from Providencia alcalifaciens, Klebsiella pneumoniae and Klebsiella oxytoca were respectively expressed in Escherichia coli (E. coli) BL21, designated as Pardh, Kprdh and Kordh respectively to identify the target genes with higher transformation rates. Further, the RDH from Klebsiella oxytoca was coupled with the formate dehydrogenase (FDH) from Candida boidinii for co-catalysis, and the catalytic conditions and the addition amounts of co-substrates were optimized to achieve efficient enzymatic catalytic synthesis of allitol. [Results]When using FDH and RDH from Klebsiella pneumoniae with an initial substrate D-piscose of 50 g/L and continuous feeding over 6 h to a total concentration of 100 g/L, in the presence of sodium formate as the auxiliary substrate, the conversion rate of allitol reached 53.3%. [Conclusion] By coupling the RDH and FDH systems, the conversion rate of allitol can be increased.