Could AI-Bred Microbes Help Save Our Plastic-Choked Oceans?

Thanks to our addiction to easy-to-use and dispose of single-use plastic, the world’s seas are a mess. If we are to save them — and the marine life in them — we need a strategy to remove the plastic plaguing the seas and figure out ways to keep these essential waters clean. 

New advances in computational biology and microbiome research could help with the development of those strategies and solutions, especially the use of microbes that actually eat plastic. Using artificial intelligence (AI) powered discovery and optimization technologies along with genetic manipulation techniques, scientists have made a great deal of progress in identifying and developing such microbes. 

Mass production of these microbes could, for the first time, enable humanity to get ahead in the race to prevent a total plastic takeover of the environment, both on the sea and land. While a great deal of work still needs to be done, researchers believe these microbes could hold the key to a cleaner and healthier environment — and better human health.

Marine plastic pollution has reached epidemic proportions. A UNESCO report contains frightening statistics: There are about 50 to 75 trillion pieces of plastic and microplastics in the ocean, which is growing by 8 to10 million metric tons yearly. Plastic waste now makes up 80 percent of all marine pollution, and within three decades, the sheer mass of ocean-going plastic will exceed the weight of all fish in the sea, according to the agency. 

Plastic can take as long as 1,000 years to decompose totally. In the meantime, it simply deteriorates into smaller pieces of microplastic, often consumed by fish, which are eventually eaten by humans and other animals. While the long-term consequences of this plastic consumption have yet to be studied, they are unlikely to be good. In any event, researchers say that the chemicals associated with microplastics are likely to lead to numerous serious health issues such as endocrine disruption, weight gain, insulin resistance, decreased reproductive health and cancer.

However, recent evidence has discovered some microbes — tiny living organisms — can essentially degrade certain plastics, signaling new hope for our polluted oceans. Take for instance, a chance discovery by a Japanese research team of a microbe “happily chewing through plastic bottles.” Another study collated a large database of additional microorganisms identified as capable of degrading plastics.  

Earlier research initially showed that microbes could reduce plastic pollution, and more recent studies show that microbes are evolving to biodegrade plastic. A Swedish team discovered 30,000 enzymes — proteins produced by microbes that build up and break down substances — that could degrade over ten types of plastic. While these enzymes can reduce pollution on land and sea, they are especially suited to digesting plastic in the ocean. 

Unlike on land, the number of these plastic-digesting enzymes increases with the depth of the water and as the presence of plastic pollution increases. This could indicate that the enzymes adjust their abilities based on the environment and amount of plastic present. It’s unclear how this evolution is taking place or through what mechanism specific microbes and genes respond to particular types of plastic, but it is a growing area of research. 

Many questions remain. A large-scale study of how microbes interact with plastic has yet to occur. Much more research is needed to develop an effective, large-scale solution to microbe-based plastic decomposition. That is likely to require genetic manipulation of microbes to whet their “appetite” for different kinds of plastic, as well as developing methods to produce them in large amounts. 

And while microbes can effectively break down certain kinds of plastic, they can take a very long time to do so, given their small size. Many microbes would be needed to make a dent in large pollution concentrations, such as the Great Pacific Plastic Patch. 

Most of the microbes discovered operate on two particular kinds of plastic: PET and PE plastics. Often used to make bottles and bags, scientists say these are “relatively easy” types of plastic to decompose. Developing microbes to decompose other types of plastics will be a more significant challenge, though progress is being made. 

Meanwhile, the decomposition of plastics could lead to other problems, such as the large-scale release of carbon dioxide, which has adverse effects on the roots of aquatic plants and abnormalities in their production of sugars and proteins and their ability to absorb nutrients.

The solution to these issues could also lie in the genetic manipulation of enzymes to increase their plastic-eating efficiency and limit or eliminate the harmful effects of releasing excess carbon dioxide or other gasses. It was also an accidental discovery that led scientists along this path. British scientists used X-rays and other tweaks to improve the effectiveness of the original plastic-eating enzymes discovered by the Japanese team, developing a new enzyme that works much more quickly and efficiently. It can also be produced in quantities, although it is primarily restricted to eating PET-type plastic. 

Meanwhile, researchers at North Carolina State University developed another genetically modified microbe that breaks down PET plastic quickly and can thrive in salt-water environments, which is a challenge in other plastic-eating microbe projects.

It is clear that recent scientific advances are enhancing the ability of microbes to consume plastics. But the potential applications for waste-eating microbes go far beyond plastics. Research is increasingly shedding light on the potential to use bacteria to address other pollutants like industrial and explosive waste. Efforts should be made to address these issues simultaneously as the options increase for using biology and living organisms to clean up the environment. 

While much more work needs to be done, it appears that microbes developed or tweaked with the help of AI and computational biology can help us in the battle against a wide range of pollutants, especially plastic in the oceans. And we need that help desperately.