In vitro synthesis of polyhydroxyalkanoate catalyzed by class II and III PHA synthases: a useful technique for surface coatings of a hydrophobic support with PHA

In vitro synthesis of polyhydroxyalkanoates (PHAs) on a hydrophobic support, i.e. highly oriented pyrolytic graphite (HOPG), was performed using class II PHA synthase (PhaC1(pp)) from Pseudomonas putida and class III PHA synthase (PhaEC(AV)) from Allochromatium vinosum. Using PhaC1(pp) and 3-hydroxyoctanoyl-CoA, a poly(3-hydroxyoctanoate) [P(3HO)] film was formed on the hydrophobic support with a thickness of a few nanometers, as revealed by atomic force microscopy (AFM). A poly(3-hydroxybutyrate) [P(3HB)] film was also formed using PhaEC(AV), and 3-hydroxybutyryl-CoA. AFM observations of the HOPG surface during P(3HB) film formation revealed that polymerized P(3HB) covered HOPG surface within the reaction time, resulting in the formation of a homogeneous ultra-thin film. This method of ultra-thin PHA film formation on a hydrophobic support may be applicable to the surface-coating technique of materials with biodegradable, bioabsorbable, and biocompatible PHAs. (C) 2009 Society of Chemical Industry