Plastic Biodegradation

Plastic waste treatment draws much attention as the material is resistant and thus hard to degradated in nature. Microplastic particles resulted from the weathering are accumulated to the human body eventually through the food chain. Currently, recycling and pyrolysis only process a small portion of plastic waste. PET(polyethylene terephthalate) hydrolase is a class of enzymes discovered in the microorganisms that are able to break down PET to its monomer in nature. The currently identified PET hydrolases are having small turn over numbers to the substrate and work slowly against high-crystalline PET (hc-PET), which is widely used in making bottles. Photocatalysis is another newly discovered method to process plastic waste and produce hydrogen gas at the same time. The reaction also takes place at a mild condition under the visible light. Plastics could be turned to CO2 in a completed reaction. Our group is working to combine the PET hydrolase and photocatalysis to increase the breaking down of the process of PET waste.

Biodesulfurization

Reducing the sulfur amount in the fuel helps to decrease the release of sulfurous oxidative which causes acid rains and green-house effects. Compared to the conventional hydrogen desulfurization (HDS) process, the bio desulphurization (BDS) process using bacteria and fungi is showing specificity to the organosulfur compounds and can be performed at a mild condition. Besides, BDS is an eco-friendly process. BDS process via the 4S pathway removes the sulfur while maintaining the caloric value of the fuels. Our group is working to improve the BDS efficiency through several aspects: protein engineering with BDS enzymes; enzyme immobilization, and extending the catalytic reaction, trying to overcome the limitations of the 4S pathway and thus to promote its utilization in the industry.