- Category: Technology
04 Jan 2013
- Published on Friday, 04 January 2013 09:59
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An enzyme capable of boosting the amount of the polymer galactan in plant cell walls could increase the amount of fermentable sugars found plant biomass, raising the amount of advanced biofuel it can produce.
The Department of Energy’s Joint BioEnergy Institute has confirmed that GT92 enzyme is the first enzyme that has the ability to increase the production of galactan. Galactan is a polymer of galactose, a six-carbon sugar that can be fermented into cellulosic ethanol.
Advanced biofuels, such as cellulosic ethanol, are a more sustainable and carbon-neutral form of fuel to replace gasoline, diesel and jet fuels. They can be used in existing engines and distributed through existing fuel infrastructure.
Galactans are components of pectin, a sticky sugar substance that binds together the individual cells in plant cell walls. The galactan component of pectin is especially abundant in what is known as “tension wood,” a buildup of woody cellulose that occurs when a plant is subjected to mechanical stress from wind or snowfall.
Tension wood has also been found to contain larger quantities of GT92 genes. This led the J.B.E.I. researchers to further investigate the function of GT92.
They used the Arabidopsis thaliana, a small flowering relative of mustard, as a model organism. Arabidopsis has three types of GT92 which they identified as GALS1, GALS2 and GALS3.
They tested the plants both with and without the genes. Those without genes were found to be galactan deficient, while those with genes had increased GALS1 with 50 percent more galactan. The scientists are anticipating similar results for plants with increased GALS2 and GALS3.
Next step would be to combine mutations of GALS genes to determine which would result in even higher production of galactan. They believe that these genes could also be found in switchgrass, miscanthus, poplar and other biomass crops that allow them to be manipulated for greater sugar content – and a potential increase in biofuel production. – EcoSeed Staff