Scientists and engineers at North Carolina State University are working on finding ways to use trees as sustainable alternatives to producing industrial chemicals from petroleum. Lignin, a polymer that makes trees rigid and resistant to degradation, has been identified as a problematic component. Researchers have discovered that the methoxy content of lignin determines how easy it is to use microbial fermentation to convert trees and plants into industrial chemicals.
Robert Kelly, the corresponding author of a study published in Science Advances, believes that the findings bring us closer to economically and environmentally sustainable production of industrial chemicals from trees. While previous research showed the potential of extreme thermophilic bacteria to degrade cellulose in trees, the high lignin content remained a challenge. Kelly has been collaborating with Associate Professor Jack Wang to address this issue, utilizing CRISPR genome editing technology to modify the lignin content and composition of poplar trees.
Research conducted by Kelly’s group, along with former Ph.D. student Ryan Bing, found that certain thermophilic bacteria have varying appetites for different types of plants, influencing their ability to degrade plant matter. They discovered that trees with lower lignin methoxy content were more degradable, providing insight into what makes a plant more suitable for microbial degradation and fermentation. These findings suggest that engineered poplar trees with low lignin and low methoxy content are ideal for the production of chemicals through microbial fermentation.
The engineered poplar trees developed by Wang’s team have shown promise in the greenhouse, but field testing results are pending. Previous research has demonstrated that low lignin poplar trees can be converted into industrial chemicals with favorable economic outcomes and low environmental impact. By focusing on trees with specific lignin properties, researchers hope to optimize chemical production from trees and enhance sustainability in the bio-based industry.
Using engineered microbes to break down lignin offers advantages over traditional methods, such as lower energy requirements and environmental impact. Enzymes can break down cellulose into simple sugars, but microorganisms can produce essential enzymes continuously, making the process more economical. The high temperatures at which these bacteria grow also eliminate the need for sterile conditions, making the conversion of trees into chemicals more feasible for industrial applications.
Researcher Daniel Sulis stressed the importance of finding sustainable alternatives to fossil fuels, particularly in light of environmental disasters caused by climate change. Harnessing trees for industrial applications offers a promising solution to meet society’s needs while protecting the planet. The findings from these studies not only advance the field but also set the stage for further innovations in utilizing trees for sustainable bio-based products.
