Poly(hydroxyalkanoate) (PHA) are non-toxic (co)polyesters, which are bioproduced by a wide range of bacteria as intracellular storage materials. These bacterial polymers can be synthesized by fermentation from a wide variety of carbon-based substrates. Different biomasses or waste plastics can be used as carbon sources. For example, poly(ethylene terephthalate) (PET) can be depolymerized at the end of its life by enzymatic or chemical hydrolysis into terephthalic acid and ethylene glycol.