Trash to Treats: How Scientists Are Turning Plastic Waste Into Vanilla Flavoring

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Plastic is undeniably ubiquitous these days. It’s in plenty of places where we expect to encounter it — the pens in our offices, the takeout containers at our restaurants, the toothbrushes in our homes, the shopping bags from our local retailers — but it’s also filling our oceans and waterways at an alarming rate. Without immediate and widespread action, it’s estimated that nearly 1.3 billion tons of plastic waste will end up in our oceans by 2040. And that’s in addition to the 8 million annual tons that have been flowing into these bodies of water in recent years.

The problems plastic waste causes are multilateral. They’re a threat to sealife, according to the International Union for the Conservation of Nature, because “marine species ingest or are entangled by plastic debris, which causes severe injuries and deaths” that harm populations of these creatures on a large scale. The organization also reports that “plastic pollution threatens food safety and quality, human health [and] coastal tourism and contributes to climate change.” For these and other reasons, environmentalists and scientists have long been searching for methods of remediating the growing problem of plastic waste.

Surprisingly, a potential solution may arise in the form of a classic confection flavoring. Scientists have recently found that, with the assistance of some helpful bacteria, plastic waste can be converted into vanillin, a synthetic compound used in vanilla scents and flavorings. Through this simple process of breaking down plastic, researchers have set humanity on a pathway to utilizing single-use plastics as valuable resources — and potentially discovered an opportunity to solve one of the most extensive environmental disasters we’re facing today.

A Brief History of the Plastic Problem

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Bakelite, the world’s first synthetic plastic, was discovered in 1907. This material “could be shaped or molded into almost anything, providing endless possibilities” for applications in the then-rapidly industrializing world. Plastic production surged as the U.S. fought in two world wars, and the 1950s saw another drastic increase in plastic production. And for the next six decades, plastic production increased 200-fold to nearly 380 million tons of plastic each year.

Paradoxically, it’s plastic’s innovation — the fact that it’s fully synthetic, made from molecules that aren’t found anywhere in nature — that’s also the source of the issues we’re facing today. Plastic doesn’t decompose the way organic materials like paper do; it can take 1,000 years for plastic to break down in landfills. So, any plastic that ends up in our environment stays there, causing untold issues to people, animals and ecosystems in general.

One good thing about plastic is that some of it can be recycled — but this comes with issues of its own. The recycling process requires responsibility on our part; people need to be vigilant about how they handle their plastic waste and ensure it ends up in a position to actually get recycled. But recycling plastic also poses a challenge due to the variety of chemical formulations that exist and the various additives used in different products. Additionally, plastic can’t be recycled repeatedly like glass due to breakdowns in its structural integrity.

Recycling plastic is certainly a helpful solution, but it’s an imperfect one. Fortunately, another reclamation method could lie in an unexpected ingredient.

What Is Vanillin, and What Does It Have to Do With Plastic?

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Vanillin, which is typically derived from vanilla beans, is an organic compound and the primary component of vanilla bean extract — it’s what creates that sugary sweet, slightly floral aroma and flavor we’re so fond of. The food industry utilizes vanillin to flavor candies, baked goods and ice cream, but the compound is also used in other types of manufacturing to create fragrances and perfumes in candles, cleaning products, anti-foaming agents and cosmetics. Vanillin even has practical value in masking the unsavory flavors in various medicines. Needless to say, vanillin is consistently in high demand in a variety of industries. And companies can’t always access it (or access it affordably) in its natural form, so they turn to the synthetic version instead.

According to an article published in the Independent, vanillin is an expensive substance, and the need for it is growing rapidly. The market for it is projected to reach $724.5 million by 2025. But how can industries scale up to meet this increasing demand, even where synthetic vanillin shortages are concerned? That’s where plastic is set to make a surprising debut. Scientists have discovered a method to make artificial vanilla by converting plastic waste into the synthetic flavoring.

Harnessing the Power of Bacterial Breakdowns

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Bacteria have been breaking things down for millennia; it’s the main function of a specific type of bacteria called “decomposters.” But these organisms are generally known for their ability to digest and break down organic matter — things like plants and animals — not synthetic materials like plastics. Still, the bacterial decomposition process got scientists thinking. What if it was possible to use a similar process to break down plastics? And what if the bacteria themselves could actually facilitate this?

As it turns out, with some help from bacteria, plastics can break down. Mutant enzymes already exist to break down plastic products such as soda bottles into basic chemical compounds. The process involves a mild reaction that doesn’t generate any extra hazardous waste. But scientists Joanna Sadler and Stephen Wallace decided to explore this concept a bit further to fully understand some of its applications — and to test the process using bacteria.

Sadler and Wallace conducted a study that was published in the scientific journal Green Chemistry in 2021. The study acknowledges the widespread uses of a type of plastic called polyethylene terephthalate (PET) in the global economy and points out the poor management of its waste products. Previous studies found that certain enzymes were able to break down PET into a type of acid, called terephthalic acid or TA, that manufacturers can then use to create new plastic products. With these findings in mind, Sadler and Wallace set out to engineer bacteria that could utilize TA in a more environmentally friendly manner — one that doesn’t result in the creation of new plastics.

Converting Plastics to Vanillin Using… E. coli?

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Interestingly, the chemical compositions of TA and vanillin are similar. With this in mind, Sadler and Wallace sought to discover what would happen when E. coli bacteria were left to their own devices among plastics that’d already been broken down enzymatically into TA.

To conduct the experiment, the pair “mixed a broth containing the engineered E. coli and TA at a temperature of 98.6 degrees Fahrenheit for a day.” The end result? The bacteria converted about 79% of the TA into vanillin — a relatively easy process for the microorganisms, considering the structural similarities of the two chemicals. The bacteria changed the number of hydrogen and oxygen atoms attached to the TA’s carbon, and, in doing so, transformed the TA into the beneficial (and profitable) compound.

Of the experiment, Sadler said, “This is the first example of using a biological system to epicycle plastic waste into a valuable industrial chemical, and it has very exciting implications for the circular economy.” Wallace also stated that this work “challenges the perception of plastic being a problematic waste and instead demonstrates its use as a new carbon resource from which high-value products can be obtained.”

What Could the Future of Recycled Plastics Hold?

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Encouraged by the data, Sadler and Wallace are continuing to explore the creation of low-cost technologies to recycle post-consumer plastic waste. The preliminary results of their experiment indicate this novel technology may have real-world implications in engineering our plastic waste into a much more valuable and sustainable material. This is just the beginning, of course, but the findings show promise. And with further optimization of this process, we could learn more about how to apply this bacteria-driven technology on a much larger scale.

We know that ignoring the influx of plastic waste into our ecosystems isn’t going to solve any problems. And while scientists continue to refine the bacteria-vanillin application, it’s vital in the meantime for us to find and implement other broad-scale methods of dealing with plastic waste before it reaches the environment. But the scientific process has led to what appears to be a valuable solution, and that’s cause for celebration — maybe one with some vanilla ice cream.