Transforming properties of lignin in softwoods

Radiata pine that is easier to process into pulp and biofuel is one step closer thanks to a team of Scion biotechnologists working in collaboration with the University of Wisconsin-Madison.

Easier-to-process softwood brings economic and environmental benefits. Needing less energy, the pre-treatment process will be faster, more efficient and less wasteful, yielding improved feedstock for pulp, paper and biofuel industries. Led by Dr Armin Wagner, the team recently published its work in the Proceedings of the National Academy of Sciences1 proving the concept that it is possible to change the makeup of lignin polymers in softwoods.

“Lignin is a complex polymer that provides strength and structure in trees,” said Armin. “In softwoods, like conifers, the lignin contains guaiacyl (G) units while hardwood liginin also contains syringyl (S) units. Lignin made up of G units is more condensed and difficult to degrade than lignin that also contains S units. This, together with the higher levels of lignin found in softwoods, makes trees like radiata pine more complicated and expensive to process than hardwoods.

Lignin TEs 

Softwood pine tracheary elements (TEs) from cells engineered to produce hardwoodtype lignin. Photo: Lloyd Donaldson, Scion, and Matt Wisniewski, GLBRC.

 

“We have shown it is possible to engineer from converting dairy cells of Pinus radiata to produce S lignin units. This suggests it’s possible to engineer softwoods, such as radiata pine, to produce easier to process hardwoodlike lignin while retaining their outstanding fibre properties.”

Metabolic engineering allows plant breeders to introduce a single, clearly identified desirable trait into a population where it is not normally or readily available. The materials used in this work were obtained from naturally occurring organisms such as bacteria, fungi and plants.

The corresponding author is renowned lignin expert John Ralph from the University of Wisconsin-Madison, Professor of Biochemistry and Plants Leader at the Great Lakes Bioenergy Research Centre. John has a long association with Scion and has collaborated on numerous projects.

For further information
Contact Dr Glenn Thorlby at
glenn.thorlby@scionresearch.com

 

1 Wagner, A., Tobimatsu, Y., Phillips, L., Flint, H., Geddes, B., Lu, F., & Ralph, J. (2015). Syringyl lignin production in conifers: Proof of concept in a Pine tracheary element system. Proceedings of the National Academy of Sciences, 112(19), 6218-6223.