[NEWS] GMO Trees Better for Biofuels
– June 28, 2016, Phys.org
Lignin is a natural component of plant cell walls, the scaffolding that surrounds each cell and plays a pivotal role in plants’ ability to grow against gravity and reach heights ranging from stubbly grasses to the sky-scraping splendor of redwoods. But lignin is a problem for scientists interested in converting plant biomass to biofuels and other sustainable bio-based products. Lignin makes it hard to break down the plant matter so its carbon-rich building blocks can be converted into forms suitable for generating energy or running automobiles.
A simple solution might be to engineer plants with less lignin. But previous attempts to do this have often resulted in weaker plants and stunted growth-essentially putting the brakes on biomass production.
Now, by engineering a novel enzyme involved in lignin synthesis, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory and collaborators have altered the lignin in aspen trees in a way that increases access to biofuel building blocks without inhibiting plant growth. Their research, described in Nature Communications, resulted in an almost 50 percent increase in ethanol yield from healthy aspen trees whose woody biomass released 62 percent more simple sugars than native plants.
“Our study provides a useful strategy for tailoring woody biomass for bio-based applications,” said Brookhaven biologist Chang-Jun Liu, the lead author on the project.
Lignin makes up about 20 percent of aspen’s woody structures, with cellulose and hemicellulose polymers making up approximately 45 and 25 percent, along with other minor components.