Reduced acetic acid formation using NaHSO3 as a steering agent by Actinobacillus succinogenes GXAS137.

Abstract

The high production of acetic acid (AC) as a by-product leads to difficult separation and purification of succinic acid (SA) and increases production costs in SA fermentation by Actinobacillus succinogenes. NaHSO3 as a steering agent was used to reduce AC production. Herein, the optimum fermentation conditions were achieved by single-factor and orthogonal tests as follows: glucose 60g/L; MgCO3 60g/L; NaHSO3 0.15% (w/v); and NaHSO3 addition time, 8h after inoculation. After optimization, the SA and AC contents were 44.42 and 5.73g/L. The SA improved by 100.72%, the AC decreased by 21.18% compared with the unfermented. The acetate kinase activity decreased by 14.36% and acetyl-CoA content improved by 97.55% in the group of NaHSO3 addition compared with control check (CK). The mechanism of NaHSO3 is formation acetaldehyde-sodium bisulfite compound and reduction the activity of acetate kinase. These findings indicated a new way of using NaHSO3 as a steering agent to reduce AC generation and may help promote the development of SA industrial production.