Transporter Engineering Enables the Efficient Production of Lacto-<i>N</i>-triose II and Lacto-<i>N</i>-tetraose in <i>Escherichia coli</i>
Tomotoshi Sugita, Kento Koketsu
Journal of Agricultural and Food Chemistry
Abstract
Lacto-<i>N</i>-triose (LNT II) and lacto-<i>N</i>-tetraose (LNT) are human milk oligosaccharides (HMOs) with various potential functions for infants. HMO production by <i>Escherichia coli</i> fermentation has attracted attention in recent years. However, little is known about the cellular export of HMOs. In this study, we identified four endogenous <i>E. coli</i> transporter genes (<i>setA</i>, <i>setB</i>, <i>ydeA</i>, and <i>mdfA</i>), overexpression of which significantly increased the efficiency of LNT II production. The <i>setA</i>-enhanced strain accumulated 34.2 g/L LNT II in a 3 L bioreactor. In the production of LNT, which uses LNT II as an intermediate, disruption of <i>setA</i> remarkably decreased the LNT II accumulation and enhanced the titer of LNT. Furthermore, by heterologous expression of extracellular β-1,3-<i>N</i>-acetylglucosaminidase from <i>Bifidobacterium bifidum</i>, which degrades LNT II, we eliminated LNT II completely. This study shows that regulation of sugar efflux transporters in <i>E. coli</i> can increase the production of HMOs and decrease the amounts of undesired byproducts.
Extracted Claims
3 claims extracted from this paper into the knowledge graph
Lacto-N-tetraose (LNT) enhanced titer
“disruption of setA remarkably decreased the LNT II accumulation and enhanced the titer of LNT.”
Lacto-N-triose II (LNT II) accumulated 34.2 g/L
“The setA-enhanced strain accumulated 34.2 g/L LNT II in a 3 L bioreactor.”
Lacto-N-triose II (LNT II) degraded completely
“by heterologous expression of extracellular β-1,3-N-acetylglucosaminidase from Bifidobacterium bifidum, which degrades LNT II, we eliminated LNT II completely.”