1 research outputs found
High-Yield Synthesis of Lacto‑<i>N</i>‑Neotetraose from Glycerol and Glucose in Engineered Escherichia coli
Lacto-N-neotetraose (LNnT) is a neutral human
milk oligosaccharide with important biological functions. However,
the low LNnT productivity and the incomplete conversion of the intermediate
lacto-N-tetraose II (LNT II) currently limited the
sustainable biosynthesis of LNnT. First, the LNnT biosynthetic module
was integrated in Escherichia coli.
Next, the LNnT export system was optimized to alleviate the inhibition
of intracellular LNnT synthesis. Furthermore, by utilizing rate-limiting
enzyme diagnosis, the expressions of LNnT synthesis pathway genes
were finely regulated to further enhance the production yield of LNnT.
Subsequently, a strategy of cofermentation using a glucose/glycerol
(4:6, g/g) mixed feed was employed to regulate carbon flux distribution.
Finally, by overexpressing key transferases, LNnT and LNT II titers
reached 112.47 and 7.42 g/L, respectively, in a 5 L fermenter, and
107.4 and 2.08 g/L, respectively, in a 1000 L fermenter. These are
the highest reported titers of LNnT to date, indicating its significant
potential for industrial production