An efficient process for the production of (R)-hydroxycarboxylic acids (RHAs) from polyhydroxyalkanoates (PHAs) was developed. It involved the synthesis of PHA in bacteria, followed by bringing the culture broth directly to a pH optimal for in vivo PHA degradation, thus avoiding cell collection by centrifugation and pellet resuspension. The optimal pH was maintained to allow maximal release of RHAs. Using this process, cells having a dry weight (w) of 1.8 g center dot L-1 and 45% (w/w) PHA exhibited a linear PHA degradation rate of about 0.059 g center dot L-1 center dot h(-1) in the first 9 h. Concomitantly, RHAs were released with a rate of 0.057 g center dot L-1 center dot h(-1). Further incubation of up to 15 h resulted in almost 90% (w/w) degradation of PHA. Based on this approach in combination with chemostat and a plug flow reactor a continuous process for the production of RHAs could be achieved.