Using Ralstonia eutropha H16 as a test organism, PHA was produced in a 2-step fermentation. In the first step, the organism was grown in a mineral medium containing vanillic acid, 4 – hydroxy benzoic acid (4-HBA), 2,5 – dihydroxybenzoic acid (2,5-DHBA) and other aromatic lignin degradation products. After shifting to richer culture conditions, the strain accumulated 63 wt% of PHA.

RIKEN news release, March 29, 2014