New bio-engineered trees make it easier to produce pulp

Researchers have genetically engineered trees that will be easier to break down to produce paper and biofuel, a breakthrough that will mean using fewer chemicals, less energy and creating fewer environmental pollutants.
"One of the largest impediments for the pulp and paper industry as well as the emerging biofuel industry is a polymer found in wood known as lignin," said Shawn Mansfield, a professor of Wood Science at the University of British Columbia, Canada.
Lignin makes up a substantial portion of the cell wall of most plants and is a processing impediment for pulp, paper and biofuel.
Currently the lignin must be removed, a process that requires significant chemicals and energy and causes undesirable waste.

Researchers have now used genetic engineering to modify the lignin to make it easier to break down without adversely affecting the tree's strength.
"We're designing trees to be processed with less energy and fewer chemicals, and ultimately recovering more wood carbohydrate than is currently possible," said Mansfield.

Researchers had previously tried to tackle this problem by reducing the quantity of lignin in trees by suppressing genes, which often resulted in trees that are stunted in growth or were susceptible to wind, snow, pests and pathogens.
The structure of lignin naturally contains ether bonds that are difficult to degrade. Researchers used genetic engineering to introduce ester bonds into the lignin backbone that are easier to break down chemically.

The new technique means that the lignin may be recovered more effectively and used in other applications, such as adhesives, insolation, carbon fibres and paint additives.
The genetic modification strategy employed in this study could also be used on other plants like grasses to be used as a new kind of fuel to replace petroleum.
Genetic modification can be a contentious issue, but there are ways to ensure that the genes do not spread to the forest, researchers said.
These techniques include growing crops away from native stands so cross-pollination isn't possible; introducing genes to make both the male and female trees or plants sterile; and harvesting trees before they reach reproductive maturity.

The study, a collaboration between researchers at the University of British Columbia, the University of Wisconsin-Madison and Michigan State University was published in the journal Science.