Biomanufacturing Sustainable Plastics in Microgravity

Before humanity can begin to traverse the vastness of space, major improvements are needed to create systems that can optimally use what is gathered from Earth as well as 

As explored in a previous piece, understanding how microgravity affects microbes is a prerequisite for interplanetary travel. Since space-based experiments are costly, simulated microgravity solutions, like Litegrav's, are needed. 

Genetically modified microbes can produce bioplastics and nanomaterials. In turn, these can be used to manufacture plastics, adhesives, and different forms of rubber. Novel materials that can be only made in microgravity are already finding terrestrial applications (Snyder, 2019).

Novel technologies, like 3D printing and microbial reprogramming, can serve as a foundation for prolonged space missions–reducing or eliminating the need to resupply (Snyder, 2019).

Spacesuits and spacecraft require plastics. Ways to manufacture strong, biodegradable plastics more sustainably with engineered microbes are being discovered.  

Scientists are modifying cyanobacteria like Synechococcus and Synechocystis to make plastics like Polyhydroxybutyrate (PHA). These bacteria are enhanced with genes from other microbes, including Cupriavidus necator, to optimize production (Koehle, 2023).

Researchers are also modifying the metabolisms of other organisms, such as Bacillus subtilis and yeast (Saccharomyces cerevisiae), to make para-aminobenzoic acid (pABA), a component of exceedingly tough materials like aramid fibers, which are used in Kevlar. Biomanufactured plastics could one day be implemented for building spacecraft parts alongside 3D-print tools and equipment in space (Koehle, 2023).

An Alternative to Plastics

A collaboration between Rhodium Scientific and Clemson University was initiated to find what benefits microgravity exposure confers on bioengineered systems. The project focused on 3D printer-compatible, biodegradable plastics called polyhydroxyalkanoates. These compounds could eventually replace common plastic packaging (GEBN, n.d.). 

They are biodegradable, gleaned from microbes and plants. They are already used in an array of areas, including medical devices (sutures, heart valves, bone scaffolds, drug delivery) and as we have noted, food packaging. However, other possible uses for them include biosensors, cosmetics, drug delivery systems, fire retardants, and electrospun fibers (Fernandez-Bunster, 2022).

Space-based applications will depend on how the polymer is created and customized. With new methods, production can be altered by genetic engineering, semi-synthetic methods, or changing carbon sources or additives. Although these compounds have a higher production cost than plastics derived from petroleum, microgravity’s advantages coupled with ongoing advances in synthetic biology, bioinformatics, and machine learning are improving efficiency while opening new avenues for novel features (Fernandez-Bunster, 2022). 

Because microgravity can elicit unpredictable and undesirable behavior from microbes, it is paramount that its effects be understood before–that is, before committing to a space mission. Simulated microgravity solutions, like those provided by Litegrav, are a way to rapidly conduct high-throughput and reproducible experiments. 

How can we make enough of these compounds in space to benefit those of us on Earth? 

In space, extracting large amounts of biomanufactured products is challenging owing to limited resources and high transportation costs. To obviate this issue, scientists are developing a method to help bacteria secrete polyhydroxyalkanoates directly. 

Normally stored as granules inside bacterial cells and covered by proteins like phasin, researchers have designed a system where phasin is fused with a secretion signal, permitting the exportation of polyhydroxyalkanoates from the bacteria (NASA, 2016). 

Manufacturing polyhydroxyalkanoates in space can then be used by astronauts for on-demand 3D printing, reducing the need to resupply. 

Once an item made with these compounds is no longer needed, it can be melted down and recycled. This can support space settlement efforts by reducing resource consumption (NASA, 2016).

Non-biodegradable plastic waste is a serious environmental concern, contributing to pollution, ecosystem disruption, and long-term sustainability challenges. Traditional recycling methods struggle to keep pace with global plastic production, making innovative solutions essential. 

Biomanufacturing research in microgravity offers an opportunity to explore enzymatic and microbial degradation of plastics, potentially leading to biodegradable alternatives, upcycling strategies, and enhanced waste management techniques. 

These advancements are not only critical for sustainable space exploration but also for scalable solutions to tackle plastic pollution on Earth. By harnessing microgravity’s effects on biological systems, researchers can accelerate discoveries that redefine how we manage and repurpose plastic waste.

References and Works Cited

Fernandez-Bunster, G., & Pavez, P. (2022). Novel Production Methods of Polyhydroxyalkanoates and Their Innovative Uses in Biomedicine and Industry. Molecules, 27(23), 8351. https://doi.org/10.3390/molecules27238351

Genetic Engineering & Biotechnology News. (n.d.). Biotechnology brings microgravity down to Earth. Retrieved from https://www.genengnews.com/topics/drug-discovery/biotechnology-brings-microgravity-down-to-earth/

Koehle, A.P., Brumwell, S.L., Seto, E.P. et al. Microbial applications for sustainable space exploration beyond low Earth orbit. npj Microgravity, 9, 47 (2023). https://doi.org/10.1038/s41526-023-00285-0

NASA. (2016). Synthetic biology for biomanufacturing of biomaterials in space (NASA Technical Report No. 20160008913). NASA Technical Reports Server. Retrieved January 7, 2025, from https://ntrs.nasa.gov/citations/20160008913

Snyder JE, Walsh D, Carr PA, Rothschild LJ. A Makerspace for Life Support Systems in Space. Trends Biotechnol. 2019 Nov;37(11):1164-1174. doi: 10.1016/j.tibtech.2019.05.003. Epub 2019 Jul 11. PMID: 31303341.

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