Escherichia coli engineering strain for efficiently producing 2'-fucosyllactose

Abstract

The invention provides an escherichia coli engineering strain for efficiently producing 2'-fucosyllactose, and belongs to the technical field of synthetic biology and microbial metabolism engineering. According to the invention, glycerol is taken as a carbon source, lactose and L-fucose are taken as substrates, and self-assembled oligopeptide-mediated pathway key enzymes Fkp and FutC are introduced to assemble and combine into an enzyme compound, so that the loss of metabolic intermediate products is reduced, the production efficiency of the products is improved, and the production yield and yield of the products 2'-FL are improved. In addition, a series of genes related to substrate degradation and intermediate product shunting in escherichia coli are knocked out through a CRISPR / Cas9 gene editing system, and meanwhile cyclic regeneration of cofactors in a metabolic pathway is enhanced, so that the yield of 2'-FL is further increased. The obtained escherichia coli engineering strain can accumulate 30.5 g / L of 2'-FL after being fed for 64 hours in batches under the condition of a 3L fermentation tank, and the molar yield is 0.661 mol(2'-FL) / mol fucose and 0.495 mol(2'-FL) / mol lactose. The invention has important significance on industrial production of the 2'-FL.

Description

technical field

[0001] The invention relates to an Escherichia coli engineering strain for efficiently producing 2′-fucosyllactose, belonging to the technical fields of synthetic biology and microbial metabolism engineering. Background technique

[0002] Human milk oligosaccharides (HMOs) are the third most abundant solid component in breast milk, which play a very important role in infant growth and development. Studies have shown that HMO has prebiotic effects, which can promote the proliferation of intestinal probiotics such as bifidobacteria and inhibit the growth of harmful bacteria, thereby regulating the intestinal flora. In addition, HMOs are able to bind pathogenic bacteria and affect the barrier function of the gut, thereby modulating local and systemic immunity. In HMOs, the proportion of fucosylated oligosaccharides is about 50%. Among them, 2′-FL is the most abundant and most common fucosylated HMOs. 2'-FL can act as a potent inhibitor of bacterial or viral a...

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