Malihe Amini

Recent technologies have been directed toward the use ofinexpensive carbon sources like agricultural wastes and wastewaters in order to produce polyhydroxyalkanoates (PHAs) in a large commercial and industrial scaleand to reducehazardous pollutants. This study aimed toproduce poly-3-hydroxybutyrate (PHB) from wastewater of the beer brewery industry using Cupriavidus necator. For this purpose, the experiments were performed at three steps to evaluate the effect ofC/N and C/Pratiosand industrial-grade maltose on biopolymer production. The batch system was chosen for the fermentation process and the alteration of bacterial growth and NH4 +-N and PO4 3−-P consumption were monitored at24 h intervals.Maximum biopolymer productionof 1.98 g L−1and biomass yield of 0.45 g biomass/g consumed sugarwere obtained at the ratio of C/N/P=100:2:15 and maltose concentration of 40 gL−1.Besides,the highest biopolymer yield and volumetric productivity associated with the ratio of C/N/ P=100:2:15 were 0.28 g g−1and 0.022 g L−1 h−1, respectively. Therefore,the C/N/P ratio of 100:2:15 and the maltose concentration of 40 gL−1were selected as the optimum condition which then generalized to the raw wastewater.The assessment of experimental data showed the amount of produced biomass and biopolymer in the raw wastewater as 7.9 and 3 g L−1, respectively. However, it can be concluded that the beer brewery wastewater has a high extraordinary potential for PHB production which could be an appropriate and eco-friendly alternative for petroleum-derived plastics.