Impact of pH and butyric acid on butanol production during batch fermentation using a new local isolate of clostridium acetobutylicum YM1

Abstract EN

The effect of pH and butyric acid supplementation on the production of butanol by a new local isolate of Clostridium acetobutylicum YM1 during batch culture fermentation was investigated.

The results showed that pH had a significant effect on bacterial growth and butanol yield and productivity.

The optimal initial pH that maximized butanol production was pH 6.0 ± 0.2.

Controlled pH was found to be unsuitable for butanol production in strain YM1, while the uncontrolled pH condition with an initial pH of 6.0 ± 0.2 was suitable for bacterial growth, butanol yield and productivity.

The maximum butanol concentration of 13.5 ± 1.42 g / L was obtained from cultures grown under the uncontrolled pH condition, resulting in a butanol yield (YP / S) and productivity of 0.27 g / g and 0.188 g / L h, respectively.

Supplementation of the pH-controlled cultures with 4.0 g / L butyric acid did not improve butanol production; however, supplementation of the uncontrolled pH cultures resulted in high butanol concentrations, yield and productivity ((16.50 ± 0.8 g / L, 0.345 g / g and 0.163 g / L h, respectively).

pH influenced the activity of NADH-dependent butanol dehydrogenase, with the highest activity obtained under the uncontrolled pH condition.

This study revealed that pH is a very important factor in butanol fermentation by C.

acetobutylicum YM1.