You may know cyanobacteria by more common forms such as Spirulina, but researchers at Michigan State University are combining these handy microorganisms with natural bacteria to make a 100% biologically derived and biodegradable bioplastic. Making bioplastics from bacteria isn’t anything new, but what is new is MSU’s new production method that does it faster, more efficiently, and much cheaper.
Researchers tweaked a cyano strain that naturally produces sugar to make them constantly leak the sugar into the surrounding salt water which had natural bacteria that fed off the leaked sugar and made bioplastic. So while cyanos work great at photosynthesis and creating chemical compounds, the natural bacteria munches up the sugar and converts it into bioplastic.
Taylor Weiss, a former post-doc in the MSU Ducat lab said, “Present bioplastic production relies on feeding plastic-producing bacteria with large quantities of sugars from crops, like corn or sugarcane. But these crops also feed people and animals, so we risk competing for limited agricultural resources and driving food prices up in the long term.”
After five months, they have some impressive stats that can really make a difference in turning these cyanobacteria/bacteria combos into feasible, cost effective bioplastic producers. According to their press release, production rates were over twenty times faster. Processed biomass contained a near constant 30% bioplastic content, four times more than the best cyano working alone. And the system is also relatively inexpensive to maintain.
Weiss said: “Harvesting bio-products is a common costly bottleneck. It involves collecting and re-growing microorganisms from scratch, each production cycle. But, we trap our cyanos in a hydrogel bead for reuse after each harvest. Sounds like the ultimate feedstock that can be reused over and over and over again.” Another big plus is that the natural plastic-producing bacteria beat out other contaminating bacteria trying to get the sugar so human intervention was not needed to keep the process going, which also helps keep the costs down. “This pair has complementary strengths: the cyanos are constantly producing sugar, and the bacteria are constantly beefing up on it, which encourages the cyanos to keep producing,” said Weiss.
MSU researchers are hoping to quickly improve the productivity and bioproduct line of their new bioplastic production method.
“We’ve laid the foundation for a “plug-and-play” system where a cyano can be gradually upgraded to produce more sugar,” said Weiss. “We eventually want to pair it with diverse specialist bacteria to create many cheaper, green bioproducts like fuels, fragrances, dyes, and medicines. Ultimately, we aren’t just creating alternatives to synthetic products. We’re figuring out how to ask nature to do what it does best: figure out the problem for us.”
The new cyanobacteria and natural bioplastic producing bacteria combination seems like it could be the winning combo we desperately need. It could alleviate the food security issues that many are concerned about when moving from fossil fuel derives bio-products to bio-based ones that come from corn, sugarcane, or other crops.
If this new production method gains traction and produces as well in commercialization as it did in the lab, it really could be the future of bioplastics and bio-based materials. The only obstacle might be getting consumers to eat from a bioplastic fork knowing it was made from bacteria.