A new enzyme can transform lignin waste using a green hydrogen peroxide base into valuable chemicals and offer a cleaner, sustainable alternative to methods based on petroleum.
About 98% of Lignin, a by -product of forestry that comes from plants, is currently being rejected. However, a newly discovered enzyme can enable the efficient extraction of valuable molecules from this waste with environmentally friendly, green chemical methods.
These extracted molecules serve as building blocks for products such as fragrances, flavors, fuels and medicines and transform a largely unused waste current into a valuable resource.
“Traditional chemical processes for the synthesis of these types of chemicals are based on start connections and heavy metal catalysts based on petroleum, which means that they do not make it renewable and naturally toxic processes” Natural communication.
“This new catalytic processing method supports the development of other new Green Chemistry 'Enzyme Factories” or BioraFineries to transform lignin and other biological waste streams into a valuable repository of fine chemicals. “
Understand Lignin and his potential
Lignin is the name that is given to the hard polymers, which act as mechanical support in hardwood and softwood and are one of the most common polymers on earth.
Agriculture and forestry collect around 100 million tons of waste -lignin per year, but this could be redirected to a promising renewable and sustainable starting point for chemicals that are currently obtained from fossil fuels.
“Strategies for the use of lignin include a combination of chemical and biological processes,” says Associate Professor Stephen Bell from the University of Physics, Chemistry and Geosciences.
“High temperatures, high pressure, strong acids and toxic solvents are used to break the polymers in the waste current.
“The valuable connections included in the waste are then extracted and are chemically processed at temperatures above 400 ° C to” valorize “the lignin. These processes are expensive and bad for the environment.”
A biological breakthrough
Hartholz Lignin has two important chemical components that require processing to establish useful connections.
The researchers had previously discovered an enzyme with which one of these compounds could be broken down, which was also found in softwood. However, no biological demolition process was identified, which was able to use the second more complex hardwood connection, which includes about 50 percent of the waste.
“The biological degradation of Lignin occurs in a complex microbial quorum, with mushroom enzymes probably breaking hard polymers, and bacteria that take the non -negligent small connections and process them to maintain metabolic energy,” said Dr. Whelan.
“In the microbial kingdom we found that a soil bacterium, Amycolatopsis ThermoflavaContains enzymes that could process molecules from lignin cheaply, with hydrogen peroxide being promoted to reaction – which makes valorization much less harmful to the environment. “
The research team has used this new enzyme as a model for retrofitting the hydrogen peroxide-powered activity in other enzymes to create green-chemical approaches of the future for the generation of high-quality application chemicals in the sectors, fragrance and medical chemistry.
Reference: “Structural insights into the S-Lignin-O-Demethylation over a rare class of hemperoxygenase enzymes” by Alix C. Harlington, Tuhin Das, Keith E. Shearwin, Stephen G. Bell and Fiona Whelan, February 20, 2025, Natural communication.
Two: 10.1038/S41467-025-57129-6