In California, scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have shown for the first time that an enzyme can be tweaked to reduce lignin in plants. Their technique could help lower the cost of converting biomass into carbon-neutral fuels to power your car and other sustainably developed bio-products.
They focused on an enzyme called HCT that plays a key role synthesizing lignin in plants. Ordinarily, the enzyme binds with a particular molecule as part of the lignin-production process. The scientists explored whether HCT binds with several other molecules that have similar structures to the original molecule, and they found HCT is pretty indiscriminate with what it accepts.
With this in mind, the researchers introduced another molecule to the enzyme that occupies the binding site usually occupied by the lignin-producing molecule. This swap inhibits the enzyme’s ability to support lignin production.
Initial tests in a model plant show this approach decreases lignin content by 30 percent while upping sugar production. What’s more, the technique promises to be much more “tunable” than the current way of reducing plant lignin, in which lignin-producing genes are silenced. This decreases lignin everywhere in a plant and throughout its lifespan, resulting in a weakened plant and a lower sugar yield.