New artificial enzyme breaks down tough, woody lignin: Study shows promise for developing a new renewable energy source

A new artificialidase has shown it can chew through lignin, a tough material that helps plants hold their shape. Lignin has a lot of potential for renewable energy and materials.

A team of researchers from Washington State University and the Department of Energy's Pacific Northwest National Laboratory reported in the journal Nature Communications that their artificialidase succeeded in breaking down lignin, which has resisted previous attempts to develop it into an economically useful energy source.

Lignin, which is the second most abundant renewable carbon source on Earth, goes to waste as a fuel source. Lignin byproducts help impart that smoky flavor to foods when wood is burned. Burning releases carbon to the atmosphere instead of capturing it for other uses.

Xiao Zhang, a corresponding author on the paper and associate professor in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering, said that the bio-mimicking enzyme showed promise in degrading real lignin, which is considered to be a breakthrough. There is an opportunity to develop a new class of catalysts and to really address the limitations of biological and chemical catalysts, which is what we think is possible.

Lignin is found in all plants and forms cell walls. Lignin makes up 20% of the weight of wood and allows trees to stand. The fine papermaking process removes lignin when it becomes yellow when exposed to air. It is often burned to produce fuel and electricity once removed.

For more than a century, chemists have tried to make products from lignin. It may be about to change.

One better than nature.

This is the first nature-mimeticidase which we know can efficiently digest lignin to produce compounds that can be used as biofuels and chemical production.

Mushroom-covered logs in the forest can be broken down with the help of fungi andbacteria. Chemical degradation requires high heat and consumes more energy than it produces, but the process of using enzymes is more eco-friendly.

Natural enzymes are hard to use in an industrial process because they degrade over time. They are also expensive.

It is hard to produce these enzymes from microorganisms in a meaningful quantity for practical use. The models that copy their basic design can be inspired by these enzymes.

Over the decades, researchers have learned a lot about how natural enzymes work. The research team has written a review article about the challenges and barriers that need to be overcome for the application of lignin degrading enzymes.

The scaffold is important.

The researchers replaced the peptides that surrounds the active site of natural enzymes with peptoids. The peptoids self-assembled into tubes and sheets. In the 1990s, peptoids were first developed to mimic the function of proteins. They have a number of unique features, including high stability, that allow scientists to address the deficiencies of the natural enzymes. They offer a high density of active sites, which is impossible to get with a natural enzyme.

We have a much higher density of active sites, instead of one, because we can precisely organize them and tune their local environments.

The artificial enzymes are more robust and stable than the natural ones, so that they can work at temperatures up to 60 degrees Celsius, a temperature that would destroy the natural ones.

Chen said that the work opens up new opportunities.

The potential for scale up to industrial scale can be achieved if the new bio-mimetic enzyme can be further improved to increase conversion yield. There are new routes for renewable materials in the technology.

The research collaboration was supported by the Bioproducts Institute. The research was contributed to by several people.

More information: Highly stable and tunable peptoid/hemin enzymatic mimetics with natural peroxidase-like activities, Nature Communications (2022). DOI: 10.1038/s41467-022-30285-9 Journal information: Nature Communications Citation: New artificial enzyme breaks down tough, woody lignin: Study shows promise for developing a new renewable energy source (2022, May 31) retrieved 31 May 2022 from https://phys.org/news/2022-05-artificial-enzyme-tough-woody-lignin.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.