A new method of recovering polyhydroxyalkanoate from Azotobacter chroococcum

After polyhydroxyalkanoate (PHA) fermentation for 42 –48 h by theAzotobacter chroococcum G-3, the PHA content reached more than 75% of the dry weight. Biomass was isolated from culture by centrifugation and pretreated with freezing to release PHA pellet, then was treated with 10 g/L sodium dodecyl sulfate (SDS) for 15 min to effectively solubilize lipid and protein. Subsequently, it was further purified by digesting with 30% sodium hypochlorite (NaClO) for 3 min to remove peptidoglycan and non-PHA biomass. Finally, 98% PHA was obtained by diluting and rinsing with water, and the PHA recovered was suitable for processing.