Current Research Themes
We are particularly interested in enzymes that microorganisms have evolved to transform coniferous wood, which is an abundant source of biomass in Canada. Accordingly, we initiated genomic and transcriptomic analyses of Phanerochaete carnosa, a white-rot fungus that was predominantly isolated from fallen coniferous trees. Having sequenced the P. carnosa genome in 2012, we are currently investigating time-dependent transitions in gene expression profiles produced by P.carnosa during growth on different softwood (coniferous) and hardwood (deciduous) preparations. In this way, it is anticipated that we will identify enzymes particularly relevant to softwood conversion, as well as proteins with unknown function that contribute to lignocellulose conversion.
Enzyme Discovery Through Metagenomic and Metatranscriptomic Analysis of Anaerobic Microbial Communities that Transform Lignocellulosic Materials
Through our participation in the Genome Canada funded program “BEEM: Bioproducts and Enzymes from Environmental Metagenomes”, we have enriched anaerobic microbial communities on a range of lignocellulosic compounds. Environmental inocula selected for these studies included samples from Canadian pulp mills, as well as digestive systems of moose and beaver, two iconic Canadian mammals known to utilize typically recalcitrant components of woody biomass. In addition to creating anaerobic enrichments that could promote bioenergy recovery from pulp mill effluents, it is anticipated that metagenomic and metatranscriptomic analysis of corresponding enrichments will reveal new enzymes relevant to biosynthesis of high-value biopolymers and chemicals from plant fibre.
Our enzyme discovery projects have revealed several enzyme candidates relevant to plant biopolymer and phytochemical engineering, including accessory hemicellulases, carbohydrate esterases, polysaccharide oxidases, multi copper oxidases (MCOs), and hydrophobins (HFBs). While we are using accessory hemicellulases and carbohydrate esterases to control and fine-tune the chemistry and performance of various hemicelluloses, polysaccharide oxidases and MCOs are being used to facilitate site-specific derivatization of plant polysaccharides and bioactive phytochemicals. Moreover, we are investigating the self-assembling characteristics of HFBs, which could be used to create functional surface coatings and multi-enzyme complexes. It is anticipated that this research will create new market opportunities for Canada’s agricultural and forest industries by generating high-value biochemicals and biopolymers from underutilized biomass fractions.
Development and Application of Analytical Techniques for Direct Assessment of Enzyme Action on Lignocellulose
While advances in “omics” techniques has accelerated enzyme discovery, our ability to fully benefit from these discoveries is limited by our ability 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, Fourier transform-infrared spectroscopy, time-of-flight secondary ion mass spectrometry, 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.
Many of these themes are part of FFABnet, our collaborative ORF-funded project that aims to harness biological processes to create high-value, high-performance chemicals and polymers from renewable plant resources.