Thursday, June 1, 2023
If you think of a major environmental problem, an everyday one that anyone can practically identify at a glance, the quickest answer will be plastic. Plastic is everywhere, and it is used for just about everything. Its footprint—and a simple walk in the woods or a park will help you see it—is just as pervasive. Solving it is fundamental and, perhaps, in this response to the problem, nature could play an active role. Unlike plastic, we cannot see them, but bacteria could hold the key to managing this waste properly.
The data on waste generated by plastics is overwhelming. According to Greenpeace's calculations, more plastic has been produced in the last ten years than had been manufactured in all of human history until then. And that material is trickling out into the wild.
An estimate by the International Union for Conservation of Nature (IUCN) in 2020 concluded that every year—and in the Mediterranean alone—the equivalent of 500 shipping containers full of plastic are dumped into the sea every day. In the final figures, that is 229,000 tons of plastic, a substantial amount that the organization estimates will double by 2040. Spain is ranked second in the list of countries that dump the most plastic into the sea, according to WWF. The NGO's research shows that 95% of all the waste that floats in the Mediterranean and ends up on beaches is plastic, and that the concentration of microplastics is already higher than on the famous "plastic island" in the Pacific Ocean.
Plastic is not just a problem for the ocean. It is also for the health of ecosystems in general and could even be problematic for human health. On average according to another WWF study, a person ingests about 21 grams of plastic per month by eating what has escaped into nature.
Reducing the use of this material, especially single-use plastics, is one of the steps being taken thanks to awareness campaigns and more restrictive regulations for their movement. This is what just happened, for example, in France, where fast food chains are no longer allowed to provide disposable tableware. But it is also crucial to improve waste management: Greenpeace estimates, for example, that in Spain 50% of all packaging ends up in landfills.
How to put an end to this "epidemic," as some call it, of plastics and stop this waste from being a problem for the planet? This is where a solution from nature itself comes into play: plastic-eating bacteria could alleviate the problem.
The idea of putting management of this waste in the hands of bacteria is not exactly new. A search in the newspaper archive shows a trail of several studies that have demonstrated the idea's potential. One of the most recent ideas is the one presented a few months ago in the journal Science, which advocates for the use of microbes. But back in the summer a paper by a Cambridge University researcher proposed enriching the water with a bacterium with a high appetite for plastic—and indirectly strengthening the ecosystem of the lakes where it lived because these bacteria were the starting point of the food chain. In fact, the University of Texas is now designing an enzyme capable of breaking down plastics in a matter of days at most and simplifying the process of reusing them.
Why this race to find bacteria that can get rid of plastic? "It is a current issue and the accumulation of plastics in the natural land and sea environments is a real global environmental problem," says María Ester López Moya, professor of the Master's Degree in Environmental and Organizational Management at the International University of La Rioja (UNIR).
As López Moya explains, "although they are recyclable, they do not readily biodegrade and are therefore highly polluting", since, as the professor notes, if they end up in nature, they can take "hundreds or even thousands of years" to disappear. "In addition, the greenhouse gas emissions that occur during plastic's entire life cycle is one of the most influential factors in climate change," she adds.
Seen in this way, the race to find the perfect bacteria to play this role is more understandable. "Because there is still no single, sustainable way to eliminate microplastics, our scientists' goal is to find effective solutions to trap, recycle, or eliminate this harmful waste," says López Moya.
The idea behind these plastic-eating bacteria has already occurred to quite a few people, but developing it and making it work is even more crucial now, in a world in where plastics are piling up and taking over everything with no effective solution to make them disappear completely, quickly and efficiently.
The benefits of bacteria
But what is it about bacteria that makes them so interesting? What are the benefits compared to other solutions that have already been considered or are already being worked on to recover plastics and prevent them from becoming a problem?
The UNIR professor points out two key points of the plastics themselves: they are difficult to degrade—the process is "complex, slow and costly"—and "they are sufficiently large" when they become waste, so that " they cannot be biodegraded."
Bacteria come into play and can break it down into elements that do not pollute, the expert notes. She notes that this is why: "It is a milestone in this field and one of the fundamental tools to be able to decontaminate ecosystems and address the most important challenge of protecting the environment." If bacteria can also improve waste management and open the door to reuse, they could make the plastic life cycle circular. And, although López Moya reminds us that we must not forget the importance of reducing plastic manufacturing, "the environmental impact would be visibly reduced."
Regarding whether the process has disadvantages, the professor points out that the question is what might be the effect of the accumulation of bacteria where they are 'attacking' the plastic. "I don't know how it would impact the environment and whether they would harm the environment or adapt easily to those specific conditions, since bacteria and other microorganisms used in the plastic biodegradation processes are living beings," she explains. That is why she notes it would have to be well studied.
And if bacteria are so promising, why aren't they already killing the plague of plastics that has become one of the great environmental liabilities? The question is not so easy because the studies are still just that: studies. "It is true that we are still in the process of researching processes and applications," states the professor, who also points out that not all bacteria are suitable for all types of plastics. However, this research is promising: it marks a potential path and, above all, helps to understand it.
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