Quantitative determination of intracellular depolymerase activity in Pseudomonas oleovorans inclusions containing poly-3-hydroxyalkanoates with long alkyl substituents.

Research regarding the accurate, quantitative degradation of novel poly-3-hydroxyalkanoates has been restricted by the absence of an appropriate monitoring technique. The calibration of a gas chromatograph to poly-3-hydroxyoctanoate reveals a linear relationship between the area under gas chromatograph tracings and polymer weight. With this new method, poly-3-hydroxy-octanoate granules isolated from Pseudomonas oleovorans, which were incubated at 30 degrees C in an alkaline buffer, exhibited a linear degradation rate. Degradation was inhibited by the presence of Triton X-100 and phenylmethylsulfonyl fluoride. The depolymerase was demonstrated to be associated with the polymer granule complex and most likely possessed serine residues at its active site.