This Scientific Focus Area Program provides fundamental knowledge about how solvents alter the structures of critical biomolecular assemblies that compose plant cell walls and microbial membranes. Structural effects are dominant in the efficient solvent-based pretreatment and deconstruction of biomass, and in product titer limitations from fermentation caused by the solvent-based destabilization of microbial membranes.
Our overarching hypothesis is that knowledge of partitioning or binding the solvent from the bulk phase to biomass or biomembranes can help predict maximal or minimal disruption. Amphiphilic solvents may be especially good at disruption of structures comprising amphiphilic molecules and polymers (e.g., membranes and biomass). Determining common biophysical principles of solvent disruption, as well as the use of shared approaches, will lead to new understandings of how solvents affect the relevant biomolecular structures. This information will help determine the ultimate microbial limits in tolerating high levels of specific solvents, as well as the eventual design of cosolvents best suited for pretreatment.
We integrate the power of world-class neutron scattering capabilities available at the Spallation Neutron Source and the High Flux Isotope Reactor with the use of leadership-class supercomputing facilities at ORNL. These capabilities are complemented by expertise in biodeuteration, biomembranes, and bacterial membrane engineering at ORNL, plant cell wall physical chemistry at the University of Tennessee, and preparing and interpreting in vitro small-angle neutron scattering membrane samples and data at the University of Cincinnati. The integrated research program is organized into three principal tasks: sample design and creation, including deuterium labeling to fully utilize neutron scattering; experimental interrogation of natural and deuterium-labeled materials by neutron and x-ray scattering and NMR; and simulation and modeling to understand of the underlying molecular forces.