Pullulan gum production from low-quality fig syrup using Aureobasidium pullulans

Pullulan is an important polysaccharide with several potential applications in food science, pharmaceutical and cosmetic industries, but high costs of pullulan production are the main limitation for commercial utilization. Therefore, a cost-effective process for pullulan production was developed using fig syrup as an exclusive nutrient source. In particular, the feasibility of using low quality fig syrup as a supplemental substrate for pullulan gum production by Aureobasidium pullulans was investigated. Fermentation was carried out over a range of fig syrup and sucrose degrees Brix (5-15%). Maximum pullulan gum production was observed after 96h using 12.5% fig syrup, yielding approximately14.06 g/L. This value of pullulan production (14.06 g/L) was higher than the amount of pullulan produced using sucrose as substrate (5.01 g/L). In conclusion, fig syrup was an effective substrate for pullulan production by Aureobasidium pullulans, and, therefore, this byproduct deserves attention for the cost-effective and environmentally friendly pullulan production.