Research ArticleMICROBIOLOGY

Significantly enhancing production of trans-4-hydroxy-l-proline by integrated system engineering in Escherichia coli

See allHide authors and affiliations

Science Advances  22 May 2020:
Vol. 6, no. 21, eaba2383
DOI: 10.1126/sciadv.aba2383

Abstract

Trans-4-hydroxy-l-proline is produced by trans-proline-4-hydroxylase with l-proline through glucose fermentation. Here, we designed a thorough “from A to Z” strategy to significantly improve trans-4-hydroxy-l-proline production. Through rare codon selected evolution, Escherichia coli M1 produced 18.2 g L−1 l-proline. Metabolically engineered M6 with the deletion of putA, proP, putP, and aceA, and proB mutation focused carbon flux to l-proline and released its feedback inhibition. It produced 15.7 g L−1 trans-4-hydroxy-l-proline with 10 g L−1 l-proline retained. Furthermore, a tunable circuit based on quorum sensing attenuated l-proline hydroxylation flux, resulting in 43.2 g L−1 trans-4-hydroxy-l-proline with 4.3 g L−1 l-proline retained. Finally, rationally designed l-proline hydroxylase gave 54.8 g L−1 trans-4-hydroxy-l-proline in 60 hours almost without l-proline remaining—the highest production to date. The de novo engineering carbon flux through rare codon selected evolution, dynamic precursor modulation, and metabolic engineering provides a good technological platform for efficient hydroxyl amino acid synthesis.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

View Full Text

Stay Connected to Science Advances