Researchers engineer yeast to grow on xylose

Researchers at Tufts University have created a genetically modified yeast that can more efficiently consume a novel nutrient, xylose, enabling the yeast to grow faster and to higher cell densities, raising the prospect of a significantly faster path toward the design of new synthetic organisms for industrial applications, according to a study published March 26 in Nature Communications.

In synthetic biology, organisms such as bacteria or yeast may be transformed into “mini-factories” when fed nutrients to produce a wide range of products, from pharmaceuticals to industrial chemicals and biofuels.

However, a central challenge has been the efficient conversion of abundant feedstocks into the final product, particularly when the feedstock is not something the bacteria or yeast normally “eat.”

In this study, the researchers noted that conventional approaches to modifying organisms to consume novel nutrients constitutively (i.e. with no “off switch”) can lead to inefficiencies when the nutrient metabolic pathways are not linked to downstream pathways for stress-responses, cell growth and other functions important for the health of the organism.

Taking a different approach, the researchers took a set of regulatory genes, called a GAL regulon, that normally processes galactose—a favorite on the yeast menu of nutrients—and replaced some of the...

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