Salty Food Waste Conversion to Bioplastics

High salinity food wastes management has been a challenge because it is inhibitory to conventional biological processes such as anaerobic digestion or composting [1]. Haloferax mediterranei (HM) is a hyperhalophilic microorganism capable of producing polyhydroxyalkanoate (PHA) from wastewater with salinity in the range of 7-30% [2]. Such a high salinity environment also protects HM from culture contamination by other indigenous organisms that came with the wasted materials [3]. Moreover, the high osmotic pressure in HM cells also allow the cell wall to burst in fresh water and thus offer low energy and chemical free PHA recovery [4]. Hence, this study demonstrated an innovative pathway enabling the bioconversion of high salinity food wastes to PHA by taking advantage of HM. The outcomes of this study include: (1) confirmed the positive effect of high salinity food waste on volatile fatty acids (VFAs) production; (2) verified that unrefined VFAs can be directly used as feedstocks for high PHA productivity; (3) proved that by fresh water can be used to open the cell walls of HM for high PHA recovery without chemical addition.