Antibiotic-Free High-Level l-Methionine Production in Engineered Escherichia coli

Journal of Agricultural and Food Chemistry, Journal Year: 2024, Volume and Issue: 72(46), P. 25791 - 25800

Published: Nov. 11, 2024

l-Methionine, a valuable sulfur-containing amino acid, holds great significance as feed additive, nutraceutical, pharmaceutical, or even in the cosmetic industry. However, achieving efficient microbial production of l-methionine remains challenging due to its complex biosynthetic pathway and plasmid loss during fermentation. Herein, biosynthesis was improved by enhancing succinyl-CoA supply, introducing direct-sulfurylation pathway, weakening l-threonine branched pathway. The engineered strain produced 21.55 g/L with yield 0.14 g/g glucose 5 L bioreactor. To eliminate need for antibiotics minimize loss,

Language: Английский

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Optimization of l-Fucose Biosynthesis in Escherichia coli through Pathway Engineering and Mixed Carbon Source Strategy

Journal of Agricultural and Food Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 3, 2025

This study presents an engineered strain of Escherichia coli specifically designed to enhance the production l-fucose while minimizing residues 2′-fucosyllactose. The optimization strategies employed include selection key enzymes, gene copy numbers, and fermentation using mixed carbon sources. metabolic flux was directed toward synthesis by integrating preferred 1,2-fucosyltransferase α-l-fucosidase into genome. Furthermore, numbers were optimized enzyme expression, thereby increasing production. Additionally, supply guanosine 5′-triphosphate improved, cofactors regenerated better regulate metabolism. Modifications transporter proteins effectively reduced accumulation implementation a glucose/glycerol co-fermentation strategy enhanced distribution efficiency. achieved yield 91.90 g/L in 5 L bioreactor, representing 80.01% increase over previous yields, with productivity 1.18 g L–1 h–1. is highest reported for l-fucose, demonstrating its potential industrial

Language: Английский

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Dual Antibiotic-Free Plasmid Systems Enable High-Efficiency l-Fucose Biosynthesis

ACS Synthetic Biology, Journal Year: 2025, Volume and Issue: unknown

Published: March 27, 2025

l-Fucose, a functional monosaccharide with significant commercial potential in the pharmaceutical, nutraceutical, and cosmetic industries, faces challenges microbial production due to antibiotic-dependent plasmid maintenance systems. This study presents dual antibiotic-free strategy engineered Escherichia coli BL21(DE3) achieve high-efficiency l-fucose biosynthesis. By integration of hok/sok toxin-antitoxin system cysC-based auxotrophic selection into two plasmids, genetic stability retention were ensured without antibiotics. Metabolic pathway optimization involved enhancing GDP-l-fucose supply via promoter replacements, genomic key enzymes (α1,2-fucosyltransferase α-l-fucosidase), blocking degradation. The strain demonstrated robust performance, producing 7.99 g/L shake-flask fermentation 61.91 fed-batch cultivation─both antibiotic-free. titer represents highest reported yield date, highlighting effectiveness combining toxin–antitoxin systems for sustainable, high-productivity manufacturing.

Language: Английский

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Iterative multimodule reprogramming and protein engineering for efficient lactodifucotetraose bioproduction

Food Bioscience, Journal Year: 2024, Volume and Issue: unknown, P. 105364 - 105364

Published: Oct. 1, 2024

Language: Английский

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