Pathway Optimization and Uridine 5′-Triphosphate Regeneration for Enhancing Lacto-<i>N</i>-Tetraose Biosynthesis in Engineered <i>Escherichia coli</i>
Zeyu Li, Yingying Zhu, Pan Zhang, Wenli Zhang, Wanmeng Mu
Journal of Agricultural and Food Chemistry
Abstract
Recently, human milk oligosaccharides (HMOs) have attracted increasing attention and display great commercial importance, especially for the infant formula industry. Lacto-<i>N</i>-tetraose (LNT) is an important neutral HMO commercially added in infant formula and a core structure for synthesizing complex HMOs. Previously, a novel LNT-generating β-1,3-galactosyltransferase from <i>Pseudogulbenkiania ferrooxidans</i> was identified and used for construction of an LNT-producing engineered <i>Escherichia coli</i>. In this work, LNT biosynthesis was further enhanced by pathway optimization and uridine 5'-triphosphate (UTP) regeneration. The main strategies included genomic integration of UDP-glucose 4-epimerase-encoding gene, fine-tuning of the LNT pathway-related genes, blocking of competitive pathways related to UDP-galactose, and overexpression of UTP supply related genes. The maximal LNT titer reached 6.16 and 57.5 g/L by shake-flask and fed-batch fermentation, respectively.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
LNT biosynthesis was enhanced by pathway optimization and uridine 5'-triphosphate (UTP) regeneration
“In this work, LNT biosynthesis was further enhanced by pathway optimization and uridine 5'-triphosphate (UTP) regeneration.”
Lacto-N-tetraose (LNT) is an important neutral human milk oligosaccharide (HMO) commercially added in infant formula
“Lacto-N-tetraose (LNT) is an important neutral HMO commercially added in infant formula and a core structure for synthesizing complex HMOs.”
LNT titer reached 6.16 g/L by shake-flask and 57.5 g/L by fed-batch fermentation
“The maximal LNT titer reached 6.16 and 57.5 g/L by shake-flask and fed-batch fermentation, respectively.”