An Increase in the Production of Butanol by Clostridium sp. Cells under the Influence of Stress Factors

Biobutanol is one of the types of biofuels produced using microbial synthesis (acetone–butanol–ethanol fermentation). It is possible to increase the level of accumulation of the target product due to metabolic changes in producer cells under the influence of stress factors. For this purpose, the effect of such stress factors as allopurinol, furfural, zinc, and oxygen, as well as glycerol as a nonspecific substrate on the functioning of Clostridium sp. cells, was studied. It was demonstrated that the butanol concentration was the highest (1.2 g/L) as compared with the control (0.6 g/L) when adding 0.5 g/L of furfural to the culture medium. The use of ZnSO 4 at a concentration of 0.001 g/L increased the butanol concentration to 1.1 g/L, and the highest butanol concentration (1.3 g/L) was obtained when using glucose and glycerol as carbon sources in a ratio of 1 : 3. The butanol concentration in the culture medium increased to 0.8 g/L with the addition of 0.025 g/L of allopurinol. The possibility of using the above-mentioned stress factors to increase the accumulation of the target product by influencing the metabolic pathways in microorganism cells is substantiated.