Charles, Trevor (University of Waterloo)

Purpose

The most commonly used herbicide on Earth is glyphosate, which kills plants by inhibiting a key enzyme involved in aromatic amino acid synthesis. It is popular for a number of reasons; low toxicity to humans and animals, short residence time in soil and water due to degradation through microbial metabolic activity, and development of glyphosate tolerant varieties of crop plants. Glyphosate is a phosphonate, with a highly stable carbon-phosphorous bond. It is readily biodegraded, however, by microbes in the soil. The details of the bacteria, the biochemical pathways, and the enzymes that are responsible for this biodegradation are not well known. Under some soil conditions, glyphosate can accumulate in the soil over time. We have assembled a team with complementary expertise in biochemistry, microbiology, bacterial genetics and metagenomics to investigate glyphosate metabolism in agricultural soils by isolating and studying new strains of glyphosate degrading bacteria, searching for novel glyphosate degradation pathways, and detailed characterization of the pathway enzymes. We will also attempt to generate evolved strains with improved glyphosate degradation properties. Our industrial partner is interested in the knowledge that we generate and the glyphosate degrading strains that we isolate for the potential future development of products for remediation of glyphosate contaminated soils. This project will contribute towards the maintenance of glyphosate as an important and valuable tool for modern sustainable agriculture in Canada.