Page 69 - Plant Canada 2024 Proceeding

PLANT CANADA 2024

Wednesday, July 10

Dr. Guanqun (Gavin) Chen
University of Alberta

“Acids for sustainable growth in agriculture
and fermentation”

Abstract: Some plant and microalgae species
can produce high levels of unusual fatty acids
(UFAs), which are valuable in the food, feed, and
oleochemical industries. Understanding the
mechanisms of their biosynthesis and regulation,
as well as developing novel genetic engineering
strategies to increase their production, is an
exciting area of research in lipid biotechnology.
This presentation will cover our work on the
biochemical characterization of proteins associated with several UFAs in plants and
their production through biotechnology. The UFAs we will discuss include long-chain n-3
polyunsaturated fatty acids, hydroxyl fatty acids, and conjugated fatty acids, with punicic
acid as a representative example.

Punicic acid is primarily sourced from pomegranate seed oil, but its productivity is very
low. Therefore, it is attractive to establish its production in engineered oilseed crops and
yeasts. By expressing cDNAs encoding pomegranate fatty acid conjugase and Δ12
desaturase, we achieved the accumulation of 11% of total fatty acids as punicic acid in
canola seeds. In Saccharomyces cerevisiae, we created recombinant libraries by
directly shuffling candidate genes within its genome using Ty retrotransposon-targeted
random gene integration. Subsequent library screening and bioprocess development
identified a recombinant strain that accumulated 26.7% of total fatty acids as punicic
acid. We also engineered an oleaginous yeast strain, Rhodosporidium toruloides, which
accumulated 12% of its total fatty acids as punicic acid with glucose as the carbon
source and 6.4% with wood hydrolysate as the feedstock.

The presentation will conclude with a general discussion of the challenges and future
perspectives in this research field.
Bio: Dr. Guanqun (Gavin) Chen is an Associate Professor and Canada Research Chair in Plant
Lipid Biotechnology in the Department of Agricultural, Food, and Nutritional Science at the
University of Alberta, Canada. His research interests include expanding our understanding of
storage lipid biosynthesis and developing biotechnological approaches to enhance oil yield and
quality in both plants and microorganisms. This knowledge platform will further enable him to
redesign lipid biosynthesis in these organisms, producing unusual fatty acids for applications in
food, nutraceuticals, and industrial settings.

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