Enhancing Bacillus licheniformis sporulation with automatic nitrogen feeding based on online detection of exhaust CO2

Abstract

AbstractThe Bacillus licheniformis formulation is effective in environmental remediation, gut microbiota modulation, and soil improvement. Adequate spore quantity is crucial for activity of B. licheniformis formulations. This study aimed to enhance B. licheniformis BF‐002 sporulation by optimizing nitrogen source feeding. In the initial four manual feeding strategies, continuous feeding based on exhaust CO2 resulted in the highest cell and spore quantities (1.44 × 1010 and 6.12 × 109 cfu/mL). Python‐based automatic feeding, based on online exhaust CO2 detection, was developed and implemented in 5 and 50 L cultivations. Compared to manual feeding, cell and spore quantities increased by 31.25% and 97.7%, respectively. Substituting costly peptone (fish) with NH4Cl reduced spore quantity by 8.46% and 9.25% in 5 and 50 L cultivations, while cutting nitrogen source cost by 87.08% and 91.39%. Employing exhaust CO2 concentration for automatic nitrogen supplementation effectively promotes Bacillus growth and spore formation.