麻豆淫院

Forestry waste can be turned into a high-value fatty acid, thanks to a bright red yeast engineered by University of Alberta researchers.

Using wood-derived sugar as a feedstock, the strain, developed from a yeast called Rhodosporidium toruloides, proved capable of producing punicic acid.

The discovery offers potential economic wins for the forestry and food industries, says study co-author Guanqun Chen, associate professor in the Faculty of Agricultural, Life & Environmental Sciences and Canada Research Chair in Plant Lipid Biotechnology. The research is in the journal Bioresource Technology.

Derived mainly from the seed oil of pomegranate fruit, punicic acid offers healthy cholesterol-lowering, anti-inflammatory and anti-carcinogenic properties. However, with a very low seed-to-fruit ratio and oil yield, it's currently not financially feasible to produce for large-scale use in the food industry.

But being able to produce the fatty acid using a sugar solution derived from low-value leftovers like wood chips provides both economic and environmental benefits, Chen says, noting that the yeast strain could also be used on agricultural byproducts such as canola and wheat straw, after pre-treatment.

"We've shown that this engineered strain can serve as an industrial platform for converting large volumes of biomass waste or byproducts into a valuable product, which may open up opportunities for creating high-value nutritional supplements, functional food and animal feed ingredients.

"That creates additional revenue, improves resource efficiency and can help sustainability for these various industries."

The strain, which is now under a provisional patent application, could, for example, serve as an alternative to using baker's yeast, the current approved choice for animal feed supplements, notes study co-author Juli Wang, who carried out the research as part of his Ph.D. thesis project in plant science.

"It's got high oil content and a quick growth rate that make it a better option for producing punicic acid using fermentation."

The research, conducted in collaboration with U of A professor David Bressler's Biorefining Conversions and Fermentation Lab, marks the first time R. toruloides was engineered to produce punicic acid.

In their experiments, the researchers genetically modified the red yeast by introducing two key enzymes from pomegranate fruit. When cultured with a sugar solution derived from the wood waste, the yeast strain produced 6.4% of its total fatty acids as punicic acid.

The discovery proves that the strain can produce a high amount of the fatty acid during fermentation, signaling the potential for producing it at the commercial level.

"We can now look at how to optimize and then scale up the fermentation process," Wang says.

The researchers plan to continue tweaking the yeast strain to boost its punicic acid content and exploring the use of other renewable feedstocks from Alberta's forestry and agricultural industries, such as sugar beet molasses.

It could also have wider-ranging uses, Chen adds. "Beyond producing punicic acid, red yeast could potentially be engineered to produce a variety of other specialty fatty acids, such as omega-3 fatty acids, which have many nutraceutical applications."