Low CO2 Boosts Microbe Bioplastic Production: Safer Gas Fermentation for Carbon Recycling

Researchers at the Institute of Science Tokyo have found that reducing carbon dioxide levels in a safe gas fermentation system can significantly increase the production of biodegradable plastic by microbes. Using Ralstonia eutropha H16, the team showed that lowering CO2 to about 1.4% by volume boosted polymer accumulation and improved carbon conversion efficiency. This approach avoids flammable hydrogen concentrations, making industrial scale-up safer. The study also revealed that increasing the activity of carbonic anhydrase, an enzyme that converts CO2 into bicarbonate, further enhanced bioplastic production under low CO2 conditions. This synergy between external carbon scarcity and internal processing could allow manufacturers to use low-concentration CO2 sources like exhaust gases. The findings offer a practical path toward circular carbon recycling and safer production of biodegradable materials.