A method for isolating polyhydroxyalkanoate (PHA) from a PHA-rich bacterial biomass the process comprising: a) treating an aqueous suspension of the PHA-rich bacterial biomass with a minimal amount of sodium hypochlorite sufficient to lyse the PHA-rich bacterial biomass at room temperature to provide an PHA-rich biomass lysate in an aqueous phase, b) separating PHA-rich biomass lysate from the aqueous phase, c) washing the PHA-rich biomass lysate with water, d) removing water from the PHA-rich biomass lysate to provide a PHA-rich biomass cake having a water content of less than 70% w/w e) washing the PHA-rich biomass cake with methanol to provide a PHA-rich biomass cake having a water content of less than 5% w/w f) optionally drying the PHA-rich biomass cake washed in step e) to provide a dry PHA-rich biomass g) mixing the, optionally dry, PHA-rich biomass with dimethyl carbonate (DMC), to provide a suspension of PHA-rich biomass in DMC h) heating the suspension obtained in step g) at a temperature from 70 to 90°C for 1-3 h under vigorous stirring to provide a suspension of cell debris and a PHA-rich DMC i) separating the cell debris from the PHA-rich DMC, j) concentrating the PHA-rich DMC to provide a PHA-DMC concentrate k) adding a cold non-solvent at a temperature from -20°C to 0°C to the PHA-DMC concentrate and mixing to provide a suspension of PHA precipitate in DMC and non-solvent l) separating the PHA precipitate from the DMC and non-solvent m) washing the PHA precipitate separated in step I) with cold non-solvent n) drying the PHA precipitate washed in step m) to provide a PHA isolated from the PHA-rich bacterial biomass. a) treating an aqueous suspension of the PHA-rich bacterial biomass with a minimal amount of sodium hypochlorite sufficient to lyse the PHA-rich bacterial biomass at room temperature to provide an PHA-rich biomass lysate in an aqueous phase, b) separating PHA-rich biomass lysate from the aqueous phase, c) washing the PHA-rich biomass lysate with water, d) removing water from the PHA-rich biomass lysate to provide a PHA-rich biomass cake having a water content of less than 70% w/w e) washing the PHA-rich biomass cake with methanol to provide a PHA-rich biomass cake having a water content of less than 5% w/w f) optionally drying the PHA-rich biomass cake washed in step e) to provide a dry PHA-rich biomass g) mixing the, optionally dry, PHA-rich biomass with dimethyl carbonate (DMC), to provide a suspension of PHA-rich biomass in DMC h) heating the suspension obtained in step g) at a temperature from 70 to 90°C for 1-3 h under vigorous stirring to provide a suspension of cell debris and a PHA-rich DMC i) separating the cell debris from the PHA-rich DMC, j) concentrating the PHA-rich DMC to provide a PHA-DMC concentrate k) adding a cold non-solvent at a temperature from -20°C to 0°C to the PHA-DMC concentrate and mixing to provide a suspension of PHA precipitate in DMC and non-solvent l) separating the PHA precipitate from the DMC and non-solvent m) washing the PHA precipitate separated in step I) with cold non-solvent n) drying the PHA precipitate washed in step m) to provide a PHA isolated from the PHA-rich bacterial biomass. <EOS>