Biosynthesis of Trans-4-Hydroxyproline By Recombinant Strains of Corynebacterium Glutamicum and Escherichia coli

Background: Trans-4-hydroxy-L-proline (trans-Hyp), one of the hydroxyproline (Hyp) isomers, is a useful chiral building block in the production of many pharmaceuticals. Although there are some natural biosynthetic pathways of trans-Hyp existing in microorganisms, the yield is still too low to be scaled up industrially. Until now the acid hydrolysis of collagen has been applied in industry. However, the environmental issues should be considered seriously. It is essential to construct new recombinant strains to develop efficient process for trans-Hyp production.

Result: In this study, the genes of trans-proline 4-hydroxylase (trans-P4H) from diverse resources were cloned and expressed in Corynebacterium glutamicum and Escherichia coli, respectively. The trans-Hyp production by these recombinant strains was investigated. The results showed that all the genes from different resources had been expressed actively. Either the recombinant C. glutamicum or E. coli strains could produce trans-Hyp in the absence of proline and 2-oxoglutamate.

Conclusions: The whole cell microbial systems for trans-Hyp production have been successfully constructed by introducing trans-P4H into C. glutamicum and E. coli. Although the highest yield was obtained in recombinant E. coli, using recombinant C. glutamicum strains to produce trans-Hyp was a potential strategy.

Keywords: Trans-4-hydroxy-L-proline; recombinant Corynebacterium glutamicum; recombinant Escherichia coli; proline 4-hydroxylases