Appl Microbiol Biotechnol (2014) 98:6085–6094 DOI 10.1007/s00253-014-5691-x
APPLIED MICROBIAL AND CELL PHYSIOLOGY
High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions Ji-Min Woo & Kyung-Mi Yang & Sae-Um Kim & Lars M. Blank & Jin-Byung Park
Received: 13 November 2013 / Revised: 13 March 2014 / Accepted: 14 March 2014 / Published online: 5 April 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting Electronic supplementary material The online version of this article (doi:10.1007/s00253-014-5691-x) contains supplementary material, which is available to authorized users. J.
APPLIED MICROBIAL AND CELL PHYSIOLOGY
High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions Ji-Min Woo & Kyung-Mi Yang & Sae-Um Kim & Lars M. Blank & Jin-Byung Park
Received: 13 November 2013 / Revised: 13 March 2014 / Accepted: 14 March 2014 / Published online: 5 April 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract Cellular responses of Saccharomyces cerevisiae to high temperatures of up to 42 °C during ethanol fermentation at a high glucose concentration (i.e., 100 g/L) were investigated. Increased temperature correlated with stimulated glucose uptake to produce not only the thermal protectant glycerol but also ethanol and acetic acid. Carbon flux into the tricarboxylic acid (TCA) cycle correlated positively with cultivation temperature. These results indicate that the increased demand for energy (in the form of ATP), most likely caused by multiple stressors, including heat, acetic acid, and ethanol, was matched by both the fermentation and respiration pathways. Notably, acetic acid production was substantially stimulated compared to that of other metabolites during growth at increased temperature. The acetic acid produced in addition to ethanol seemed to subsequently result in adverse effects, leading to increased production of reactive oxygen species. This, in turn, appeared to cause the specific growth rate, and glucose uptake rate reduced leading to a decrease of the specific ethanol production rate far before glucose depletion. These results suggest that adverse effects from heat, acetic acid, ethanol, and oxidative stressors are synergistic, resulting Electronic supplementary material The online version of this article (doi:10.1007/s00253-014-5691-x) contains supplementary material, which is available to authorized users. J.
