High-Yield Synthesis of Lacto-<i>N</i>-Neotetraose from Glycerol and Glucose in Engineered <i>Escherichia coli</i>
Yingxue Liao, Caiwen Lao, Jinyong Wu, Lixia Yuan, Yanyi Xu, Weijian Jin +4 more
Journal of Agricultural and Food Chemistry
Abstract
Lacto-<i>N</i>-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-<i>N</i>-tetraose II (LNT II) currently limited the sustainable biosynthesis of LNnT. First, the LNnT biosynthetic module was integrated in <i>Escherichia coli</i>. 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.
Extracted Claims
4 claims extracted from this paper into the knowledge graph
Lacto-N-neotetraose (LNnT) produced Escherichia coli
“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.”
Lacto-N-neotetraose (LNnT) produced Escherichia coli
“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.”
Lacto-N-tetraose II (LNT II) produced Escherichia coli
“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.”