From pollution to polymer: Methane-munching microbe brews biodegradable plastic at high speed

Scientists have tapped into methane-consuming bacteria, Methylocystis suflitae, to produce biodegradable plastics called polyhydroxyalkanoates (PHAs), offering a dual win for climate and sustainability. Through genomic analysis of the bacterium, the team discovered four distinct genes responsible for producing PHA synthase, a critical enzyme in plastic synthesis. Advanced protein modeling and molecular docking revealed how these enzymes efficiently bind substrates, with hydroxybutyrate and hydroxydodecanoate showing the strongest interactions.

The team optimized fermentation conditions to achieve a high PHA production rate of 11.90 mg/L/h, a critical advance for industrial use where low methane solubility often hampers efficiency. The resulting plastic matched commercial quality, displaying a melting point of 188°C and a distinct infrared signature confirming its structure.

This breakthrough not only converts methane—a potent greenhouse gas—into eco-friendly materials but also overcomes key industrial bottlenecks. Leveraging the natural adaptability of methane-consuming bacteria to low methane environments, the study opens doors to scalable, cost-effective bioplastic production, bridging the gap between waste gas recycling and sustainable manufacturing.

The work entitled “Methylocystis suflitae as a promising industrial workhorse for methane-based polyhydroxyalkanoate production” was published on Systems Microbiology and Biomanufacturing (published on Dec. 29, 2024).