Let’s face it, learning about renewable energy is awesome. Everything from electric cars to solar power to the ongoing research into nuclear fusion gets us excited for a cleaner and better future. Renewable energy, often referred to as clean energy, comes from natural sources of processes that are constantly replenished. While renewable energy is often thought of as a new technology, harnessing nature’s power has long been used for heating, transportation, lighting, and more. And when it comes to harnessing nature’s power, this includes everything. This includes a new artificial enzyme that has shown it can chew through lignin, the tough polymer that helps woody plants hold their shape. Lignin also stores tremendous potential for renewable energy and materials.
In a recent study published in Nature Communications, a team of researchers from Washington State University and the Department of Energy's Pacific Northwest National Laboratory showed that their artificial enzyme succeeded in digesting lignin, which has stubbornly resisted previous attempts to develop it into an economically useful energy source.
Lignin, which is the second most abundant renewable carbon source on Earth, mostly goes to waste as a fuel source. When wood is burned for cooking, lignin byproducts help impart that smoky flavor to foods. But burning releases all that carbon to the atmosphere instead of capturing it for other uses.
"Our bio-mimicking enzyme showed promise in degrading real lignin, which is considered to be a breakthrough," said Xiao Zhang, a corresponding author on the paper and associate professor in WSU's Gene and Linda Voiland School of Chemical Engineering and Bioengineering. Zhang also holds a joint appointment at PNNL. "We think there is an opportunity to develop a new class of catalysts and to really address the limitations of biological and chemical catalysts."
Lignin is in all vascular plants, where it forms cell walls and provides plants with rigidity. Lignin allows trees to stand, gives vegetables their firmness and makes up about 20-35% of the weight of wood. Because lignin turns yellows when exposed to air, the wood products industry removes it as part of the fine papermaking process. Once removed, it is often inefficiently burned to produce fuel and electricity.
Chemists have tried and failed for more than a century to make valuable products from lignin. That track record of frustration may be about to change.
"This is the first nature-mimetic enzyme which we know can efficiently digest lignin to produce compounds that can be used as biofuels and for chemical production," added Chun-Long Chen, a corresponding author, a Pacific Northwest National Laboratory researcher, and affiliate professor in chemical engineering and chemistry at the University of Washington.
If the new bio-mimetic enzyme can be further improved to increase conversion yield, to generate more selective products, it has potential for scale up to industrial scale. The technology offers new routes to renewable materials for aviation biofuel and biobased materials, among other applications.
While wood makes for great campfires, this research once again demonstrates how harnessing nature’s power can be used for the good of humanity. What further energies will be revealed from this research? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!