At Seed Health, we believe health is not just human—the microbiome extends beyond our own bodies into Earth's ecology. We founded SeedLabs to advance emergent environmental research and develop novel microbial innovations to enhance, restore, and prioritize the health of our planet and the species on it.
Introducing MicroPET: A new environmental research initiative in collaboration with MIT Media Lab Space Exploration Initiative, the National Renewable Energy Laboratory (NREL), Weill Cornell Medicine, and Harvard Medical School. Together, our team of researchers created a biological system that taps into the power of bacteria and enzymes to uniquely degrade plastic and convert it into environmentally benign molecules for reuse (dubbed 'new plastic') and redesign (think: a sneaker, a chair, even a spacesuit).
The technology has been proven to work on Earth, and last fall we sent the first bacteria to upcycle single-use plastic for further testing aboard the International Space Station (ISS) via SpaceX CRS-26. Harnessing the power of bacteria and enzymes, the experiment unlocks a new method for the degradation, reuse, and redesign of synthetic plastic that could reimagine the future of waste management—both in spaceflight and on Earth.
Prior to 1950, plastic was barely a part of American life. Its advent ushered in a profound cultural revolution—an era of material abundance and 'throw-away' culture that transformed daily life, but quickly led to society's plastic dependence.
While many single-use plastic products have a use time of mere minutes to hours, it's unclear how long it takes for it to biodegrade in the environment completely. Estimates range from 450 years to never. Meanwhile, plastic production has increased exponentially (from 2.3 million tons in 1950 to 448 million tons by 2015) and is expected to double by 2050. This global accumulation of plastic in our environment has been named a planetary crisis by the United Nations.
Up until this point, recycling has been the primary method for curbing the accumulation of plastic, but it's estimated that only about 9% of plastic waste generated in the United States is actually recycled––the rest ends up in landfills, incinerators, and marine environments. Recycling isn't enough to fix––or even slow––the plastic pollution crisis we're facing.
Research also shows that even if governments around the world adhere to their global commitments to address plastic pollution, and all others join in these efforts, in 2030 we will still emit between 20 million and 53 million tons of plastic waste into the world's aquatic ecosystems. Global commitments do not match the scale of the problem—we need to rethink our strategy, and we believe biology may offer a natural solution.
What if the solution to this modern problem lay with the first inhabitants of Earth––microbes?
From wax worms to bacteria, biological organisms have been shown to degrade and catabolize human-made plastics as carbon and energy sources, but the ability to upcycle plastic is a new frontier that has yet to be explored. We took our experiment one step further with the intention of not just breaking down plastic, but transforming degraded compounds and microbially upcycling them into materials more advanced and even more sustainable.
Our experiment first introduces polyethylene terephthalate (PET) to an enzyme, which breaks it down into organic compounds, then utilizes the bacterial strain Pseudomonas putida to convert these compounds into ß-ketoadipic acid (BKA)—a high-performance nylon monomer that can then be polymerized and used in various products.
For background, plastics are long chains of chemical building blocks that can be molded and manufactured in a huge variety of materials. Different types of plastics have different building blocks, and different molecular links between them. If we can efficiently break the chains back into their building blocks, then we can efficiently recycle plastics. One way to really specifically break those chains is by using enzymes: some enzymes can depolymerize certain polymers into their monomers. However, imagine we want to make a new high-value material from an old low-value material – say, a spacesuit out of single-use packaging. To do this, we can use an engineered microorganism to convert, or metabolize, the single-use plastic monomers into the monomer for the new material. Our experiment aims to do this in space using technology built and proven on-Earth.
The ß-ketoadipic acid our process creates from waste PET can be used in a wide range of materials, including high-performance clothing, fasteners and machine parts, and construction materials, all of which have applications for space travel, like spacesuits and spacecraft replacement parts. However, a diverse array of products could be engineered as the upcycled target instead, including the building-blocks for recyclable-by-design plastics, fuels, and even food.
The system we've built and sent to the International Space Station operates on a pre-programmed experiment schedule. To enable this experiment, our collaborators at MIT Media Lab developed the first version of a compact, modularized bioreactor that allows us to autonomously run, scale, and monitor biological experiments with precision in space. The system allows for automatic media transfers and precise data monitoring from integrated sensors (e.g. temperature, optical density), and it was designed to be entirely autonomous, enabling culturing and data collection without the need for any human intervention.
Why send it to space? The International Space Station has various growth conditions that can be challenging to replicate on Earth, namely microgravity and radiation. By conducting our experiment in space, we have the opportunity to explore, optimize and evaluate the survival of plastic-eating strains of bacteria and bacteria-derived enzymes among unique conditions. We will then apply those key learnings from space to our experiment here on Earth.
But we must remember that our Earth is also a spaceship—for us, the impact of this research goes beyond space flight to benefit our home planet. If the data from our experiment in space proves to be successful and we are able to expand our research, we could reimagine the future of sustainable waste management itself.
With this project, we continue our mission of partnering with visionary researchers and institutions from around the world, using the 'new biology' of the microbiome to advance novel solutions for planetary health.