Recovery of polyhydroxyalkanoates (PHAs) from mixed microbial cultures by simple digestion and saponification

Abstract

Highly efficient separation and purification of polyhydroxyalkanoates (PHAs) from PHA-containing cell mass is essential for the production of bioplastics from renewable resources in a cost-effective, environmentally friendly way. Combination of digestion and selective dissolution of non-PHA cell mass (NPCM) using low concentration of sodium hypochlorite of PHA biopolymers, a simple process is developed and has demonstrated to recover PHA from cell mass to high purity (>90 wt %) with high yield (>90 wt %). Saponification was applied to separate or remove oil from the PHA-particles. This method was adopted in this study and was able to increase the PHA extraction from the mixed microbial intracellular biomass up to 85% of cell dried weight (CDW).