A biodegradable rubber from bacteria, poly(hydroxyalkanoate) from Pseudomonads

Poly[(R)-3-hydroxyalkanoates] (PHAs) are biopolymers stored by bacteria, which are currently receiving much attention because of their potential as renewable and biodegradable plastics. Best-known representatives are poly(hydroxybutyrate) and its copolymers with hydroxyvalerate, which have been commercialized under the trademark Biopol(TM). In addition to these rigid materials, the elastomeric medium-chain-length PHAs produced by fluorescent Pseudomonads are now emerging. These PHAs can be cross-linked by conventional techniques, yielding a biodegradable rubber with constant properties over a wide temperature range. Such a material can ideally be handled as a latex product, and one typical application would be a paper coating.