Abstract: There is provided a process for producing polyhydroxyalkanoate (PHA) comprising the steps of culturing a biomass containing PHA-producing microbes in a culture media; and hydrolyzing said PHAs-producing microbes using microorganisms selected to release PHAs from the PHAs-containing microbes. There is also provided a method of increasing the proportion of PHAs-producing microbes relative to non-PHAs producing microbes in a culture media containing both PHAs-producing microbes and non-PHAs producing microbes and a method of extracting PHAs from PHAs-containing microbes.