Abstract: Provided are nucleic acids and vectors that collectively encode various gene products related to converting styrene to polyhydroxybutyrate (PHB). In some embodiments, the nucleic acids and vectors collectively encode a styrene monooxygenase polypeptide, a flavin reductase polypeptide, a styrene-oxide isomerase polypeptide, and a phenylacetaldehyde dehydrogenase polypeptide, an acetyl-CoA C-acetyltransferase polypeptide, a 3-ketoacyl-ACP reductase polypeptide, a class I poly(R)-hydroxyalkanoic acid synthase polypeptide, and optionally an influx porin polypeptide. Also provided are systems and methods for producing PHB from styrene, methods and systems for remediating polystyrene waste. In some embodiments, the systems are in vivo systems.