Possibilities of butyric acid production by butanol oxidation with Gluconobacter oxydans coupled with extraction

J. Zigová, J. Švitel and E. Šturdík

Abstract
In this work the production of butyric acid by oxidation of butanol with Gluconobacter oxydans CCM 1783 has been studied. Butanol was added into a bioreactor in portions (0.15 mol l–1 per addition). After 75 hours of biooxidation a concentration of butyrate of 0.56 mol l–1. representing 93.3 % of theoretical yield, was achieved. The productivity for butyrate was 0.66 g l–1 h–1. In order to decrease the inhibitory effect of product and to achieve higher butyrate productivity, the possibility of butyric acid extraction with Hostarex A327 (w = 20 %) in oleylalcohol was studied. For higher extraction efficiency, the fermentation broth should be acidified to at least pH 5 before extraction. Sufficient butyrate concentration in the stripping solution could be reached with a higher volume ratio of Hostarex A327 (w = 20 %) in oleylalcohol to stripping phase.

This work is licensed under a Creative Commons Attribution 4.0 International License

Keywords
Butyric acid, butanol, extraction, Gluconobacter oxydans, oxidation, bioconversion