Patent ID: 8357508

Claim:
A process for extracting and recovering polyhydroxyalkanoates (PHAs) from a bacterial cellular biomass that has been obtained by fermentation, comprising the steps of: i) submitting the cellular biomass to concomitant operations of: injecting a liquid form PHA solvent and a vapor form PHA solvent into the cellular biomass, vigorously agitating and rapidly heating the biomass in the interior of a reactor to form a suspension comprising the PHA solvent enriched with PHA at a concentration of at least 2% by weight of the suspension and insoluble residues of the cellular biomass; ii) submitting the suspension on to a separating step for recovering the solvent enriched with the dissolved PHA from the insoluble residues of the remaining cellular biomass; iii) submitting the solution of PHA solvent enriched with PHA to agitation and washing with water and/or steam at a temperature sufficient to evaporate substantially all PHA solvent and precipitate the PHA; iv) evaporating the remaining solvent from the precipitated PHA, until depletion thereof, by injecting steam in said PHA suspension, in order to obtain particles of purified PHA in aqueous suspension; v) cooling the suspension in aqueous medium, from which the PHA solvent was depleted, to about 45° C. or less, and separating the PHA particles from said suspension; and vi) submitting the separated PHA particles to a drying step, wherein the PHA solvent is isoamyl propionate.