Design and Performance Testing of Airlift Reactor for Fungal Biomass Protein Production Using Tofu Whey

This study presents the design and performance evaluation of a lab-scale Internal Airlift Reactor (IAR) for Fungal Biomass Protein (FBP) production from tofu whey using Aspergillus oryzae. The reactor was designed based on established geometric ratios, and batch fermentation was conducted for 48 hours at 35 °C. The effects of sparger type on foam formation and aeration rate on liquid circulation and dissolved oxygen (DO) were investigated. Results showed that a PVC sparger prevented foam formation. Optimal liquid mixing occurred at an aeration rate of 2 vvm, while DO levels decreased with increasing aeration, with the highest DO value (7.7 mg/L) obtained at 1 vvm. Therefore, 1 vvm was selected as the optimal aeration rate for FBP production. Under these conditions, the process yielded 1.98 g/L of dry biomass and 0.73 g/g substrate conversion, with a protein content of 6.51% (g/g). The findings demonstrate that the IAR system can effectively convert tofu whey waste into valuable fungal biomass, emphasizing its potential for efficient and sustainable bioprocess applications.