Fig. 6

Batch fermentation profiles of the microbial consortium for butyl butyrate production with different aeration speed control strategies. The consortium strains were inoculated at a ratio of 1:8 (butyrate strain: butanol strain) and cultured at 200 rpm, pH 5.8. C: control, aerated with 0.5 vvm during the whole fermentation process. 1: aerated with 0.5 vvm in the first 24 h, then shifted to 0.1 vvm. 2: aerated with 0.5 vvm in the first 36 h, then shifted to 0.1 vvm. The data represent the means ± SD from three biological replicates