Biodegradable plastics, unlike conventional plastics have a hydrolysable backbone, which makes them susceptible to degradation by microorganisms. The biodegradability of these materials are certified according to internationally-standardized testing methods, and are graded as compostable (industrial or home), soil or wastewater biodegradable. However, as the global market share of biodegradable plastics increases, it is still not clear how these new materials would behave in the marine environment due to lack of standardized testing schemes, the complexity of the marine ecosystem and the diversity of materials. In this project, we aim to uncover biodegradation mechanisms of several commercially-relevant biodegradable plastics with culture based and independent approaches. The ultimate aim is to address questions regarding the marine environmental fate of these materials, uncover biodegradation mechanisms and hopefully to use these newly-discovered marine enzymes to enhance the recycling of biodegradable (and conventional) plastics.
Bacteria have the unique capability to degrade and mineralize chlorinated aromatic hydrocarbons. The ability of environmental microorganisms to adapt to and degrade synthetic aromatic hydrocarbons is well-studied; however with the emerging of new sequencing technologies, we are able to address a broader range of questions regarding the adaptation of microorganisms to these xenobiotic compounds. In this project, we aim to spy on the lives of several bacterial species that degrade phenylurea herbicides, and try to elucidate how microbes isolated from geographically-distant locations adapt to the same synthetic substrate.
A broad aim of this project is to uncover the mechanisms behind the adaptation of proteins that degrade natural compounds to synthetic compounds, and how short evolutionary pathways lead to the expansion of substrate ranges and enzyme families.