Abstract
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This work investigated the capability of Rhizopus arrhizus to assimilate biodiesel-derived crude glycerol and convert it into fumaric acid. After optimizing the initial glycerol concentration, spore inoculum and yeast extract concentration, smaller pellets (0.7mm) and higher biomass (3.11g/L) were obtained when R. arrhizus grew on crude glycerol. It was found that crude glycerol was more suitable than glucose for smaller R. arrhizus pellet forming. When 80g/L crude glycerol was used as carbon source, the fumaric acid production of 4.37g/L was obtained at 192h. With a highest concentration of 22.81g/L achieved in the co-fermentation of crude glycerol (40g/L) and glucose (40g/L) at 144h, the fumaric acid production was enhanced by 553.6%, compared to the fermentation using glycerol (80g/L) as sole carbon source. Moreover, the production cost of fumaric acid in co-fermentation was reduced by approximately 14% compared to glucose fermentation.