Optimization of Oil Production Fermentation and Analysis of Fermentation Process for Chemical induction of Fungus Penicillium Citrinum Asc2-4 associated with Pyrosomella verticilliata

Abstract

Increasing the biomass and oil production of the Pyrosomella verticilliata associated fungus Penicillium citrinum Asc2-4 using inorganic salt chemical induction. The results revealed that KH2PO4, MgSO4, and FeCl3 were significant in promoting oil concentration, and orthogonal optimization revealed that adding these three inorganic salts at 4 g/L, 1.5 g/L, and 1.0×10-7 g/L could increase amount of biomass and oil concentration to 14.52 g/L and 4.73 g/L, respectively, which were 29.64% and 89.20% higher than before fermentation optimization. Gas chromatography analysis of the fatty acid content and the fraction of the bacterial oil revealed that the oil contained as much as 94.08% C16 and C18 fatty acids, and the bacterium has the potential to being employed as a raw material for biodiesel. The fourth day of fermentation with filamentous fungal form proved to be beneficial for the fungus to collect oil, with the sugar-oil conversion rate reaching 15.30%, making it a suitable time point for sugar supplementation fermentation. The fourth and sixth days had the greatest values for biomass and oil concentration, respectively. This research can serve as a theoretical foundation for the advancement of industrial oil production by Penicillium citrinum Asc2-4.