Papermaking requires a lot of harsh and toxic chemicals to strip wood pulp of lignin, a tough polymer that makes trees strong and rigid. Wood chemist Vincent L. Chiang and a team of researchers from Michigan Technological University are trying to come up with a better solution: aspen trees that are bioengineered to produce less lignin. Their work was published in the August issue of Nature Biotechnology.
To create their trees, the scientists blocked the activity of a key lignin-producing molecule in the woody part of the tree. The result was a new strain of aspen with 45% less lignin. Surprisingly, engineered trees also grew 1.5 times faster and laid down more extensive root systems than their unmodified cousins. This may mean that more wood can be grown from less land using Chiang's trees, thus reducing the environmental impact of forestry. But aspens aren't normally processed to make paper, so Chiang's team is trying to repeat the result in two more popular pulpwood species, eucalyptus and pine. "It's a neat result that could make paper production easier and more economically viable," says Ronald R. Sederoff, a forestry expert at North Carolina State University.