Aureobasidium pullulans modified by genetic engineering and adaptive evolution: Efficient production of pullulan from potato starch industrial waste

With the growing demand for potato starch, there is an urgent need to address the associated waste. Aureobasidium pullulans has the potential to utilize potato residue to produce high-value pullulan; however, low utilization rates and underdeveloped technology present significant challenges. In this study, high-yield strains were generated through UV mutagenesis, and transcriptome sequencing was conducted to identify differentially expressed genes. Overexpression engineered strains OEX-GHF3-4, OEX-UDPG-6, and UDPG-GHF3 were constructed, increasing pullulan yield by 110.18 %, 150.62 %, and 217.64 % compared to control, respectively. Finally, adaptive evolution and resource optimization methods were employed to investigate the maximum yield of UDPG-GHF3 following overexpression, resulting in a 304.73% increase in yield. The approach's viability was further confirmed through a 500 L scale-up, the yield of pullulan reached 32.55 g/L, presenting a cost-effective, high-yield strategy for pullulan production and offering a sustainable method for recycling potato starch industrial waste. • Constructing efficient strains for the resource-based production of pullulan • Adaptive evolution enhances the resource utilization of Aureobasidium pullulans • A carbon cycling technology has been developed to reduce costs and enhance returns • This strategy is beneficial for the regeneration of waste resources