Development of efficient processes where biomass is used as raw material for sustainable production of biofuels and biochemicals is important for the transition into a fossil-free society. However, efficient degradation of residues from the forest industry is challenging as plant biomass contains lignin. Removal of lignin is not only difficult, but also expensive. The key to success may be a certain type of enzyme that can facilitate and accelerate the degradation of biomass.
Lignocellulose, the main component of residual biomass from the forest industry, is an important raw material to produce, among other things, bioethanol. It is a complex material, difficult to process in a cost-effective way, due to the strong chemical bonds between lignin and carbohydrates.
Johan Larsbrink, Associate Professor, and Scott Mazurkewich, postdoc, both at the Division of Industrial Biotechnology at Chalmers, participated in a research project in collaboration with several universities, where a recently published study has shown that − and how − the enzymes glucuronoyl esterases can break these chemical bonds.
How did you conduct this study and what were your results?
"This is an in-depth study with computer modelling, biochemistry and structural biology to understand mechanistically how the enzyme cuts bonds in plant biomass. The results show which of the enzyme's amino acids are most important to facilitate the reaction, and how the rate-limiting step is the enzyme itself being able to detach from the biomass to find a new position to cut", says Scott Mazurkewich.
Why did you start to investigate this group of enzymes?
"When we started the project, very few studies had been done on glucuronoyl esterases and in particular there was a lack of detailed information on the atomic scale. Thus, this has been both curiosity-driven research to understand how these enzymes work, but also to discover how they can be used in applications that can reduce the use of fossil raw materials. Using plant biomass in smarter ways to create new materials is also the main focus within the research center, the Wallenberg Wood Science Center, where both Scott and I are active, " says Johan Larsbrink.
What can your results lead to?
"The discovery provides an increased understanding of the factors that affect these enzymes' efficiency. The knowledge could be used to determine which type of enzymes are best suited for the degradation of different types of biomass," says Johan Larsbrink.
About the study:
- The study is a collaboration between the University of Copenhagen, Nankai University, Chalmers University of Technology, and the University of Campinas.
- Read the scientific article Mechanism and biomass association of glucuronoyl esterase: an α / β hydrolase with potential in biomass conversion
Text: Susanne Nilsson Lindh
Photo (portraits): Martina Butorac
