The new production method uses an inexpensive modified E. Coli strain to quickly synthesise the human milk oligosaccharide 2-fucosyllactose (2FL), which until now has not been widely studied or utilised.
“We know these oligosaccharides play a vital role in developing a breast-fed baby’s gut microbiota and in strengthening their immunity,” said Professor Michael Miller from the University of Illinois, USA, who led the research. “2FL is the most abundant HMO [human milk oligosaccharide] in breast milk.”
Despite 2FL being the most abundant of all human milk oligosaccharides, very little research has been conducted on the sugar because of its high costs. Just 1mg costs $100 (€77), meaning that until an alternative production method could be put in place any research on the breast milk oligosaccharide would cost millions for the ingredient supply alone.
The high cost of 2FL has also been cited as a key reason for its absence in infant formula.
Cheap and quick production
Writing in the journal Microbial Cell Factories, Miller and his colleagues reveal how the oligosaccharide can now be produced using the modified E. Coli strain. The team says the bacterially synthesised 2FL can be produced very cheaply and quickly – with a current return of 1 gram of 2FL per litre of E. Coli broth.
“E. coli makes a starting material for 2FL as part of its normal metabolism, and that suggested to us that it was possible to use E. coli to produce 2FL,” explained, Yong-Su Jin – a metabolic engineer also at the University of Illinois.
“And we can use this technique to synthesize and study the hundreds of other HMOs in human milk too,” added Miller
“The trick is to get the E. coli cells to increase their production of the starting material (GDP-fucose), which we did by overexpressing the pre-existing biosynthetic pathway,” explained Jin. “Then we had to give it the ability to transfer GDP-fucose to lactose. We solved that problem by inserting a gene from another organism.”
The engineer said the next step was to modify the E. Coli strain so that it would assimilate lactose: “Because the engineered mutant cannot use the lactose for its own growth, it instead uses lactose to make great quantities of 2FL, the HMO that many researchers want to study,” said Jin.
As a result of the new technique, Miller says he will soon be able to begin a study investigating the role of 2FL in infant nutrition – and may eventually be able to make recommendations about whether it should be added to infant formula.
In addition to its potential use in infant nutrition, the researchers suggest 2FL could be useful in reducing the risk from Campylobacter.
“If chickens consumed poultry feed containing 2FL, pathogens would bind to this oligosaccharide instead of the mucosal lining of the bird’s intestine and be eliminated well before the chicken arrived at your supermarket,” Miller added.
Jin and Miller also believe the Campylobacter protection could have applications in military nutrition: “Adding 2FL to the food of soldiers on deployment could keep them out of sick bay,” said Jin. “More than half of all soldiers in the field are incapacitated at some point with diarrheal illness caused by Campylobacter jejuni.”
Source: Microbial Cell Factories
Volume 11, Number 48, doi:10.1186/1475-2859-11-48
“Whole cell biosynthesis of a functional oligosaccharide, 2' -fucosyllactose, using engineered Escherichia coli”
Authors: Won-Heong Lee, Panchalee Pathanibul, Josh Quarterman, Jung-Hyun Jo, Nam Soo Han, Michael J Miller, Yong-Su Jin, Jin-Ho Seo