Using ANOVA Models To Compare and Optimize Extraction Protocols of P3HBHV from Cupriavidus necator

Polyhydroxyalkanoates (PHAs), produced by microorganisms, have attracted considerable attention due to their biodegradability. However, the cost for the production of PHA is still too high to be competitive against petro-based polymers, greatly caused by the expensive downstream processing (DSP). The DSP, moreover, is often ecologically unfriendly due to usage of large amounts of highly volatile organic solvents. To overcome these limitations, we systematically compared for the first time seven different extraction protocols reported previously using the same starting biomass of Cupriavidus necator. Design of experiments (DoE) and analysis of variance (ANOVA) models were applied to further improve two of the most promising protocols. Finally, we developed a method where a combination of mechanical disruption of cells via bead milling with an addition of sodium lauryl sulfate (SDS) was used. This method was optimized with a response surface methodology and allowed a fast PHA extraction within approximately 2 h with a PHA recovery of almost 100% and PHA purity of 94%.