Current Research Themes

Discovery and development of enzymes to functionalize plant biopolymers

We are isolating and engineering carbohydrate-active enzymes to upgrade (rather than degrade) plant polysaccharides and lignin. To date, we have focused our efforts on the discovery, characterization, and development of accessory hemicellulases, carbohydrate oxidoreductases, transaminases, and multicopper oxidases. The discovery and development of accessory hemicelluases is important given the potential of these enzymes to tailor the chemistry of complex plant polysaccharides to thereby control their miscibility, adsorption properties, and chemical reactivity. Carbohydrate oxidoreductases and transaminases with ability to functionalize the termini of oligosaccharides or polysaccharide backbones are also valuable enzymes for re-assembly and/or targeted chemical derivatization of biomass fractions.

Biophysical characterization and application of microbial expansin-related proteins

Microbial expansin-related proteins are non-lytic proteins with potential to disrupt inter-fibrillar bonding within cellulosic and chitinous networks. Accordingly, these proteins have potential to widen applications of renewable biofibres through moderating their solubility and dispersibility. We are mining the growing number of microbial genome sequences and establishing complementary biophysical methods to identify expansin-related proteins with distinct substrate preference and applied potential.

Expanding analytical methods for direct assessment of protein action on lignocellulosic materials

While advances in “omics” techniques has accelerated enzyme discovery, our ability to fully benefit from these discoveries is limited by our capacity to characterize enzyme action on relevant substrates. Accordingly, the objective of projects within this research theme is to apply state-of-the-art analytical techniques to characterize enzyme action directly on lignocellulose components. Methods being applied include isothermal calorimetry, measurements using quartz-crystal microbalance with dissipation, time-of-flight secondary ion mass spectrometry, x-ray photoelectron spectroscopy, and scanning transmission x-ray microscopy. In addition to translating enzyme discovery to application, it is anticipated that these studies will advance our fundamental understanding of enzyme accessibility and action on complex composite materials.