Research Spotlight: Karan Aletty and lignin


Have you ever wondered why trees are so sturdy, but paper made from trees is so thin? This is because trees contain strong polymers called lignin and cellulose. Since lignin is so strong, bacteria can easily break down the cellulose in wood so it can decompose, but lignin cannot decompose as easily. So, to make material such as notebook paper or newspapers, lignin must be separated from the cellulose. Unfortunately, this means that this tough substance becomes nothing but harmful waste to the environment.

That is where researcher (and junior Chemistry major) Karan Aletty and his research sponsor, Dr. Karin Young, Assistant Professor of Chemistry, come in. Aletty is currently undertaking a research project to minimize the consequences lignin can have on our environment, by studying a small portion of the whole protein, and comparing it to a type of coal called lignite. While lignite is not identical to lignin in its properties, it is rather similar, as it is a structurally condensed form of lignin. This allows for fairly in-depth experiments that can examine a way to limit the polymer’s environmental consequences.

The only way to break lignin down is to apply high heat and pressure, which takes up energy and is not very effective.

“The reason why we are trying to break it down is because high heat and high pressure are not green for the environment,” Aletty said. Indeed, such facets of our daily lives, such as taking notes on notebook paper, can have harmful long-term effects on our environment, and minimizing its effects can be an important step towards a green future.

How are Aletty and Dr. Young planning to decompose lignin? In nature, there is a fungus called White rot fungus that uses natural chemicals to break lignin down.

White rot fungus breaks down lignin’s tough structure with an oxidation process that uses oxidizers, such as hydrogen peroxide. According to Aletty, this process is entirely natural, and therefore not as hazardous as methods we use to break down lignin in a man-made fashion.

“We are trying to mimic the White rot fungus in order to redevelop a greener approach,” says Aletty.

The White rot fungus is typically found through aerobic composting, and conditions that favor it are nitrogen, moisture, and temperature, which can be hard to regulate over as much space as would be needed to decompose the amount of lignin we waste each year.

They plan to limit lignin, a large macromolecule, by focusing on a few structures that are easier to study and do experiments on. Aletty and Dr. Young will simplify this reaction by using a smaller model compound—vetrayl alcohol—as lignin, and oxidizing it with oxone, to mimic the oxidative activity of the enzymes. Using smaller models makes it easier to see results in a shorter time frame. They are optimistic about the results, though Aletty says that they are only in the first stage of the experiment.

So, why is this important? Because paper is so cheap, and is used in virtually every school and workplace, finding a way to minimize its harmful impacts is more important than ever before. Saying that paper – and therefore lignin – is not green may be an understatement.

In the United States alone, paper is responsible for 76.1 tons of waste per year, and comes with more hazards than just the long-lasting affects of lignin, such as toxic inks and dyes that can be carcinogenic when incinerating, and can spread to groundwater, harming our water supply. Our widespread use of paper has the potential to harm many vital parts of nature that are not only disastrous for the environment, but for humanity.


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