Science in your Laundry Detergent

When I was a kid, if I got a grass stain or a blood stain on my clothes it was probably not coming out no matter how much presoaking and hand scrubbing was involved. Nowadays, if I get food on my clothes, I admonish myself for being clumsy then throw it in the wash with some liquid detergent and hope that it magically comes out looking new. It still amazes me that it usually does. How have laundry detergents improved their cleaning efficacy so much in just the last few decades? It turns out, it’s more than just fancy soap. Laundry detergent contains special ingredients that have been developed by science to get your clothing clean using less electricity.

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Laundry out to dry. Image Credit: Bruce Guenter via Flickr.

Traditional soap gets its cleaning power by acting as a surfactant, in other words it can break apart the barriers between compounds that don’t normally mix, such as oil and water. In this way soap allows water molecules to mix into stains on clothes and separate them into smaller bits that can be washed away.

How do special ingredients in laundry detergent save electricity? Modern detergents are formulated to function at low temperatures, meaning your clothing should get just as clean using a cold wash as a warm wash. So what are these “special ingredients”? They are enzymes, or specialized proteins, that help break down the molecular structure of stains on your laundry. The three main types of enzymes that may be included in your detergent are amylases (which break down carbohydrates or sugars), proteases (which break down proteins), and lipases (which breakdown fat and oil molecules). Proteases help with removing grass stains, while amylases work better on chocolate stains.

How are enzymes identified/found?

Scientists don’t create enzymes out of nothing, instead they look to nature to find enzymes that are produced by living organisms. How do scientists know which organisms might produce useful enzymes? Enzymes that break down sugars, proteins, and fats actually occur in most living organisms including plants and animals. However, there is one group of organisms that is known for their ability to break down these compounds, fungi.

Fungi obtain food from the world in their own unique way. Like animals, fungi are heterotrophs, meaning they can’t produce their own food so they obtain from sources outside their body. While animals generally ingest food to digest it and absorb nutrients, fungi take a different approach. They excrete digestive enzymes into their environment to break down larger molecules that can then be absorbed.

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Fungi. Image Credit: Elias Gayles via Flickr.

Researchers are focusing their detergent enzyme finding efforts on fungi because of their unique style of obtaining food. Scientists search forest floors and decaying trees for a particular type of fungi, mushrooms, that can be studied to identify new enzymes that are effective in laundry detergents.

How the Enzymes are Produced?

Once a useful enzyme is identified, it needs to be produced in large quantities to be used in a commercially produced detergent. One way this could be done is to isolate it from mushroom tissue, but that would require A LOT of mushrooms. Instead, scientists identify the mushroom gene that produces the enzyme, and insert it into a microbe like bacteria, or yeast. Microbes are very small and can be grown quickly. Once the microbes have the gene, they can produce the enzyme in large quantities.

What is the Benefit of Enzymes in Laundry Detergent?

Enzymes improve the efficiency of the laundry process, by utilizing less water and energy while still cleaning effectively. As researchers identify additional enzymes our detergents will continue to improve and be able to remove the most stubborn stains. It’s possible that in ten years teenagers will be baffled that anyone would be concerned about removing a grass stain. So the next time you spill coffee on a new shirt (it happens to me a lot) thank a fungi for the stain fighting enzymes in your detergent!

 

About the Author

Karen BobierKaren Bobier is a Ph.D. candidate in the Department of Genetics studying populations of freshwater fishes in North Georgia and the evolution of DNA methylation genes. In her spare time she enjoys reading, hanging out with her dog, and is a member of the Red and Black Archery Club. You can email her at Karen.bobier25@uga.edu. More from Karen Bobier.