Public Release: 

Modified plants may yield more biofuel

Penn State


Lignin, a major component of woody plant material, is woven in with cellulose and provides plants with the strength to withstand strong gusts of wind and microbial attack. However, this protective barrier or "plastic wall" also makes it harder to gain access to the cellulose.







These enzymes that attack proteins are already used widely in the laundry detergent industry and are commercially readily available, added Carlson.


"When we looked at the first generation of modified plants we noticed that the lignin content has not changed," said Tien, whose work is funded by the U.S. Department of Energy. "We haven't done a fitness test yet but we did see an increase in the yield of sugars for converting into ethanol."

The researchers may also have stumbled on an unexpected side benefit.

One of the problems with forage crops such as ryegrass and clover is that they have too much lignin, which can cause ruminants like cows to get sick. Their digestive enzymes go into overdrive to break down the lignin, creating a lot of gas and digestion problems for the animals.

"All animals produce enzymes in their digestive process that break down amino acids and small proteins that can be absorbed by the intestine," said Carlson. "If this technology were to be transferred to alfalfa or hay or such cattle feed, it might make it easier for the cows to break down the lignin through their own enzymes."

Carlson added that the technology could potentially be transferred to other biomass crops and even help turn agricultural waste products found on farms into animal feed. But the modified plants will require federal approval before they can be commercialized.

