Extraction and purification of Polyhydroxyalkanoates (PHAs): application of Thermoseparating aqueous two-phase extraction

Being biodegradable, non-toxic and renewable as well as having similar or better properties than commercial plastics, polyhydroxyalkanoates (PHAs) can be a potential game changer in the polymer industry. Although viewed as a sustainable alternative to petrochemicals due to its biodegradability, PHAs are plagued with low commercial value due to their high production and recovery costs. Having the benefits of providing a mild environment for bioseparation, being environment-friendly and scalable, together with it its distinctive thermoseparating properties and ease of recyclability, thermoseparating-based aqueous two-phase extraction (ATPE) has provided the eco-friendly and economical solution to the PHA dilemma. ATPE-influencing factors such as types of thermoseparating polymer, concentration of phase-forming components, pH, and effect of centrifugation were investigated. Under the condition of 14 wt/wt% of EOPO 3900 concentration, 14 wt/wt% of ammonium sulfate concentration and pH 6 without the needs for extra centrifugation steps, a recovery yield and a purification factor of up to 72.2% and 1.61 fold can be achieved with the copolymers which can be recycled and reused twice. Thermoseparating ATPE has thus been proven to be a powerful primary purification tool for PHAs.