The accumulation of plastic waste is a worldwide problem with detrimental effects on our natural environments. Not only does it accumulate at rates that parallel its production, but the current strategies to recycle some of these plastics, such as polyethylene terephthalate (PET), are insufficient in generating a circular economy and impeding plastic waste accumulation. 

Strikingly, a mesophilic bacterium has been described to secrete enzymes that degrade PET at temperatures near 40ºC. Have we found the most efficient natural PET-degrading enzyme? Are there any enzymes that can degrade PET at lower temperatures? What about higher temperatures?

In this seminar, Cesar shares the efforts of his research group on discovering and characterising novel PET-degrading enzymes from different environments that catalyse this depolymerisation at different temperatures, including the identification of Antarctic enzymes that degrade PET at room temperature and plant compost enzymes that efficiently degrade PET at high temperatures. 

Then, we will discuss how protein engineering and computational biology enable us to redesign these enzymes to generate potential candidates to enable the biological degradation of PET.

About the Speaker

Cesar Ramirez-Sarmiento is an Associate Professor at the Institute for Biological and Medical Engineering (IIBM) from the Pontifical Catholic University of Chile and an Adjunct Researcher at the Millenium Institute for Integrative Biology (iBio).

He obtained his PhD in Molecular and Cellular Biology and Neurosciences at the University of Chile, and he also received doctoral training in biophysics and computational biology at the University of California San Diego.

His research group employs experimental and computational strategies to unveil the folding-function-evolution relationships of many proteins of biomedical and biotechnological interests.

On the one hand, his research group studies metamorphic proteins that dramatically change their three-dimensional structure to regulate crucial cellular processes, such as bacterial virulence and cyanobacterial circadian cycles.

On the other hand, his research is focused on the discovery, characterization and engineering of bacterial enzymes that hydrolyse PET, a widely used plastic that accumulates as waste in landfills and natural environments at similar rates to its production.