Enhancement of adenosine production by bacillus subtilis cgmcc 4484 through metabolic flux analysis and simplified feeding strategies

The objective of this research was to understand how the initial glucose concentration influences adenosine (AR) production and metabolic flux shift on the cultivation of Bacillus subtilis CGMCC 4484. Experiments confirmed that initial glucose concentration affects cell growth, AR production and metabolites, significantly. The flux distribution at the key nodes of glucose-6-phosphate (G6P), pyruvate (PYR) and acetyl coenzyme-A (AcCoA) could be affected by changing the glucose concentration. Based on kinetic analysis of specific rates, the low-glucose concentration was better for both cell growth and AR production during the first 12 h. However, the high-glucose concentration was more favorable for AR formation after 18 h. Furthermore, different simplified feeding strategies were designed to achieve higher AR accumulation. The final AR concentration of 15.60 g L^-1was achieved when an optimized constant-feeding strategy was used, which was 21.02 % higher than batch fermentation. This was the first time to investigate the regulation of the glucose metabolism of AR-producing B. subtilis.