Plastic surrounds us. It wraps our food, clothes our bodies, houses our electronics, and unfortunately, fills our oceans. This versatile material, which has transformed modern life, now poses a major environmental challenge. Most plastics come from petroleum, and its creation contributes to climate change. And as is well known by now, plastics will persist in our environment for centuries.
Scientists at Korea’s Advanced Institute of Science and Technology recently reported a promising solution to this dilemma in the journal Nature Chemical Biology. They engineered common E. coli bacteria to produce a new type of plastic that combines the strength and durability of nylons with the potential biodegradability of certain polyesters.
Creating a material of this nature requires remarkable scientific ingenuity because bacteria do not naturally make anything that resembles nylon. Researchers had to develop a new metabolic pathway by introducing specific genes from other bacterial species and had to reprogram the bacteria’s biochemical capabilities to create materials that are not created naturally. This is like installing new biochemical software into bacteria, enabling them to perform previously unimaginable tasks.
The engineered bacteria became highly effective chemical producers, incorporating amino acid building blocks into plastic polymer chains. Amino acids are typically found in proteins but not in plastics. The microbes produced these plastics using glucose, a simple sugar, pointing toward a future where plastics could be sustainably produced from renewable plant sources rather than fossil fuels.
The final product was quite versatile. When evaluating these bacteria-made plastics, researchers found they could adjust characteristics like flexibility and melting temperature by modifying their composition. One promising version exhibited properties similar to high-density polyethylene which is a familiar plastic found in milk jugs and shopping bags. This raises the possibility of replacing petroleum-based plastics with microbial alternatives in the future.
What makes these bacterial plastics likely to be more biodegradable is their unique chemical structure. By incorporating amino acids which are biological molecules that naturally occur in living systems these plastics include chemical bonds that natural decomposers like bacteria and fungi can more easily break down. This contrasts with the bonds in conventional plastics.
We currently produce hundreds of millions of tons of plastic annually worldwide. Bacteria-produced plastics offer a fundamentally different approach by giving us materials intentionally designed to break down more naturally. The result should be significantly reduced plastic accumulation in the environment.
That said, realistically this technology is likely several years away from commercial application as scientists refine the process and reduce costs. Several technical hurdles need solutions before these innovative materials are ready for consumers. Scaling up from laboratory flasks to industrial bioreactors presents substantial economic challenges. The production process is more costly than conventional plastic manufacturing, and extracting the plastic currently requires breaking open bacterial cells. But despite these challenges, the potential applications extend far beyond replacing everyday plastics. Biodegradable materials hold promise for medical innovations, such as dissolvable implants or targeted drug delivery systems. They could also transform agriculture by providing environmentally friendly materials.
Bacteria are nature’s recycling experts. And in a way, microbes are sustainable factories of the future, capable of both creating and decomposing synthetic materials. Microbes are everywhere around us, performing chemical transformations that are more sophisticated than many industrial processes. So, it stands to reason that harnessing their abilities will lead to more sustainable innovation in the future.
So, the next time you discard a plastic container, consider a future where it might be produced by microbes and ultimately decomposed by other microbes!
(Anirban Mahapatra is a scientist and author, most recently of the popular science book, When The Drugs Don’t Work: The Hidden Pandemic That Could End Medicine. The views expressed are personal.)
