Recently, a research team from the Institute of Plasma Physics, the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, successfully developed an engineered Escherichia coli strain capable of efficiently producing L-fucose, achieving a substantial increase in yield.
The research findings have been published in the Journal of Agricultural and Food Chemistry.
L-fucose is a rare monosaccharide known for its roles in promoting gut health, reducing lipid levels, supporting cancer prevention, and enhancing skin hydration. However, conventional production methods have been hampered by high costs and low yields, posing a challenge for industrial-scale application.
The research team systematically optimized the metabolic pathways of Escherichia coli through metabolic engineering. They first screened and integrated key enzyme genes, including α-1, 2-fucosyltransferase and α-L-fucosidase, to direct the metabolic flux towards L-fucose synthesis. By optimizing the gene copy number, they significantly enhanced enzyme expression levels, thereby increasing L-fucose production.
Additionally, the team enhanced the supply of guanosinetriphosphate (GTP) and nicotinamide adenine dinucleotide phosphate (NADPH), optimized metabolic regulation, and engineered the 2'-fucosyllactose transporter to reduce the accumulation of 2'-fucosyllactose, further improving the production efficiency of L-fucose.
In terms of fermentation strategy, the team adopted a co-fermentation method using glucose and glycerol, optimizing carbon source allocation and improving strain fermentation efficiency. This approach improved nutrient utilization and fermentation efficiency, ultimately enabling the engineered strain to reach an impressive L-fucose titer of 91.90 g/L in a 5-liter bioreactor — a record-setting level that is 80.01% higher than previously reported values, with a productivity rate of 1.18 g/L·h.
This study not only provides a new technological route for the industrial production of L-fucose but also offers valuable experience and strategies for the field of microbial metabolic engineering.
Schematic Diagram of L-Fucose Biosynthetic Pathway Optimization and Fermentation Performance Enhancement (Image by XIA Zihan)
