Batch fermentation kinetics study of biosynthesis lipopeptides by Bacillus altitudinis Q7 in 5 L fermenter

Abstract

Optimization of fermentation parameters can effectively increase microbial metabolites. The fermentation conditions of biosynthesis lipopeptides by Bacillus altitudinis Q7 (B. altitudinis Q7) in 5 L reactor were optimized and the fermentation kinetics were monitored throughout the fermentation process. By design-response surface methodology, the results showed that under optimal conditions (72 h, pH 6.6, 31 °C, 3% inoculum, 200 rpm, 1.5 L/min aeration), the lipopeptide yield reached 1.689 mg/mL, 24.5% higher than under single-factor conditions, with maximum biomass dry weight of 1.650 g/L. According to the logistic and Luedeking-Piret approximate models, kinetic equation models of growth, product (lipopeptide) synthesis, and substrate (glucose) utilization during the fermentation process were simulated. This was done to fit variables and devise optimal control strategies. The research has improved the yield of target products in fermentation processes, reduced production costs and provided a theoretical basis for the simulation, optimisation and regulation of fermentation in modern industry.