Immobilization of the engineered Raoultella ornithinolytica BF60 for biocatalytic synthesis of 2, 5-furandicarboxylic acid.

As a bio-based platform chemical, 2, 5-furandicarboxylic acid (FDCA) is a promising substitute of terephthalic acid to synthesize poly (ethylene furanoate) used for bio-substitute of polyethylene terephthalate (PET). In previous work, we engineered a Raoultella ornithinolytica BF60 strain and achieved the effective biocatalytic synthesis of FDCA from 5-hydroxymethylfurfural (HMF). Herein, to improve the reusability of the engineered R. ornithinolytica BF60 cells, we used two materials PVA1799-boric acid and sodium alginate-Ca2+ to immobilize the cells. The sodium alginate-Ca2+ was more suitable for FDCA production, and 22 mmol/L FDCA was obtained with Ca(H2PO4)2 as the cross-linker. In addition, the immobilization conditions were optimized and FDCA production was further increased to 74.8 mmol/L. Here the developed immobilization strategy for R. ornithinolytica BF60 cells may be helpful for the economical production of FDCA in the future.