Leong Y., Koroh F., Show P., Lan J., Loh H.-S., 2015, Optimisation of Extractive Bioconversion for Green Polymer via Aqueous Two-Phase System, Chemical Engineering Transactions, 45, 1495-1500.
Being renewable and biodegradable, the “green-polymers”, polyhydroxyalkanoates (PHAs) have been extensively studied as a potential substitute for conventional plastic due to increasing concern towards the environment. However, high raw material cost and downstream recovery cost has always been the bottleneck for wide applications of PHAs. Among PHAs recovery methods, the main principle for aqueous two-phase system (ATPS) is to promote the accumulation of biopolymers in favour of one phase using environmental-friendly phase-forming components. Having the advantage of providing mild environment for bioseparation together with capability to handle high operating capacity and reducing downstream processing volume, extractive bioconversion via ATPS which integrates upstream fermentation and downstream purification can be the perfect solution. Extractive bioconversion of PHAs by Ralstonia eutropha H16 via ATPS has been studied by investigating effects of pH and addition of salts and modellingby using Design ExpertTM. The optimum result obtained in this study is PHA concentration and recovery yield of 0.139 g/L and 65 % using ATPS of polyethylene glycol 8,000/sodium sulphate with conditions of pH 6 and addition of 0.5M NaCl.
