Clemson University

Colloquium: César A. Ramírez-Sarmiento


Department of Physics and Astronomy Zoom: R6Zz09

Meeting ID: 962 6907 1707

Password: 567780

Thursday, April 22, 4:00 pm


Characterization of novel enzymes from bacterial genomes and metagenomes that break down PET at moderate temperatures


César A. Ramírez-Sarmiento

Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile

Millennium Institute for Integrative Biology (iBio), Millennium Science Initiative Program, ANID

Polyethylene terephthalate (PET) is one of the most commonly used synthetic plastic in the packaging industry. Unfortunately, it accumulates as waste in landfills and oceans at rates that parallel its annual production. While mitigation of the impact of PET waste has been achieved through thermomechanical and chemical recycling methods, they merely account for 10-20% reutilization.

Strikingly, several microorganisms have been described to encode enzymes that catalyze a depolymerization of PET, termed PETases. These enzymes often require reaction temperatures between 60 to 70°C for an efficient hydrolysis of PET. However, an enzyme from the mesophilic bacteria Ideonella sakaiensis (IsPETase) was recently reported to enable partial hydrolysis of PET at temperatures between 30 to 40ºC.

Here, we will describe how a combination of structural biology, molecular docking and molecular dynamics led to identity the key sequence and structure features that enable IsPETase to degrade PET at moderate temperatures. Based on these findings, we search for novel PETases that could degrade PET at room temperature in Antarctic genomes and metagenomes. Our search led us to describe an enzyme from the Antarctic bacteria Moraxella sp. strain TA144 that is able to hydrolyze PET at 25 ºC, and to identify several genes from Arctic and Antarctic metagenomes that encode for potential PET hydrolases that are active at low temperatures.

FUNDING: ANID-FAPESP 2019/13259-9, ANID – Millennium Science Initiative Program – ICN17_022, PCI REDI170624.

Dial-In Information R6Zz09

Meeting ID: 962 6907 1707

Password: 567780

Thursday, April 22, 2021 at 4:00pm to 5:00pm

Virtual Event
Event Type

Lectures / Seminars / Speakers

Target Audience

Students, Faculty, Undergraduate, Graduate, Postdocs


College of Science, Physics and Astronomy

Contact Name:

Amanda Ellenburg

Contact Phone:


Contact Email:


Recent Activity