NREL researchers produce first macromolecular model of plant secondary cell wall; more efficient utilization of biomass for fuels, chemicals, and materials
07 January 2024
Researchers with the US Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL) have defined quantitatively the relative positioning and arrangement of the polymers in Populus wood and to create a computer model that details the findings.
The research into solving this macromolecular puzzle, which appears in an open-access paper in the journal Science Advances, may hold the key to disentangle and deconstruct biomass efficiently for conversion to fuels, chemicals, and materials.
In this rendition of the macromolecular model of the secondary cell wall in poplar wood, cellulose is shown in white, hemicellulose in green, and lignin in yellow. Image by Peter Ciesielski, NREL
Scientists have long known that the secondary cell wall of hardwoods involves three major biopolymers—cellulose, hemicellulose, and lignin—but detailed and quantitative understanding of how these polymers are arranged relative to each other has remained elusive.
The researchers capitalized on advances in the field of solid-state nuclear magnetic resonance (ssNMR) technology to infer refined details about the structural configuration of the cell wall, the intermolecular interactions, and the relative positions of the biopolymers within the wood. Solid-state nuclear magnetic resonance (NMR) spectroscopy is an atomic-level method to determine the chemical structure, 3D structure and dynamics of solids and semi-solids (Reif et al.).
The research was funded by two DOE research centers, The Center for Bioenergy Innovation from the Biological and Environmental Research program and the Feedstock-Conversion Interface Consortium from the Bioenergy Technologies Office.
The use of ssNMR allowed researchers to construct a computer model of the cell wall, which provided greater insight into the role lignin plays. Considered a recalcitrant part of the cell wall when it comes to breaking down biomass, lignin is notable for lending plasticity to a plant.
Articulating results into a computationally accessible molecular model is fundamentally more useful than a conceptual illustration. It allows us to rapidly evaluate hypotheses about the roles and behaviors of each component in a physics-based environment and unlocks the power of modern high-performance computing. This will help design more efficient deconstruction approaches or identify molecular modifications to produce better biobased materials.
—Peter Ciesielski, co-corresponding author
Yannick Bomble, the other co-corresponding author of this study, said prior research into the makeup of a secondary cell wall relied on techniques that overall yielded incomplete or inconclusive results. Those findings produced drawings with approximations of the connections between the biopolymers.
Here’s the first time we really have a glimpse of the structure altogether with a quantitative technique providing that level of detail. That’s never been achieved before.
—Yannick Bomble
Resources
Bennett Addison et al. (2024) “Atomistic, macromolecular model of the Populus secondary cell wall informed by solid-state NMR.” Sci. Adv.10 doi: 10.1126/sciadv.adi7965
Reif, B., Ashbrook, S.E., Emsley, L. et al. (2021) Solid-state NMR spectroscopy. Nat Rev Methods Primers 1, 2 doi: 10.1038/s43586-020-00002-1
Comments