Researchers in Polymer Journal quantified how Cupriavidus necator processes odd-chain fatty acids to make polyhydroxyalkanoates (PHA), a bio-based and biodegradable plastic. Using propionic acid, most carbon flows through alpha oxidation into acetyl-CoA, producing P3HBV with a 3-hydroxyvalerate content that matched predictions. With pentanoic acid, beta oxidation played a smaller role, and longer odd-chain fatty acids were fully oxidized to pentanoyl-CoA before polymer formation. The practical takeaway is control. Knowing the oxidation rates for each feedstock makes it easier to tune the 3HV fraction in PHA and target specific material properties. That matters because PHA still needs to compete with fossil-based plastics on cost and consistency. The study also tested 5-hydroxypentanoic acid and 1,5-pentanediol as feedstocks, which broadens the options for producing other PHA copolymers.
