Transgenic Lignin Easier to Break Down for Biofuel
Lignocellulosic biomass is a very desirable feedstock for biofuel production. If the fermentation process could be optimized, conversion of this biomass could yield 25 to 50 billion gallons of ethanol or other biofuels per year.
Yet lignocellulose is composed of tough lignin, cellulose and hemicelluloses that resist breakdown. This limits the conversion of biomass into fermentable sugars. Pretreatment steps require high heat, harsh chemicals and large amounts of water.
Lignin can be modified by introducing weaker structure chemicals like coniferyl ferulate (CAFA). Decoding the enzymes responsible for these chemicals could lead to new transgenic plants.
UW–Madison researchers and others have developed methods to genetically alter the structure of plant lignin to be less resistant to chemical (mostly alkaline) degradation.
They have identified and isolated nucleic acids from the Angelica sinensis plant that encode feruloyl-CoA:monolignol transferase. This enzyme produces lignin rich in CAFA and similar chemicals, and thus contains ester bonds that cleave under relatively mild conditions.
Plant cells can be modified to contain the enzyme gene sequence using standard genetic techniques. Whole plants (and their seeds) then can be generated from these cells.
- Makes plant material easier to break down
- By reducing the severity of the required pretreatment step, this discovery should lead to savings in both energy costs and water consumption.
- May enable sustainable local processing without massive facility costs
- Processing low-density plant materials locally may decrease transportation costs and reduce greenhouse emissions.
- May make animal feed more digestible
- Applicable to many types of plants
- Conversion of lignocellulosic biomass to biofuels and industrially important chemicals
- Production of pulp for papermaking
- Production of animal feeds and forages