TY - JOUR
T1 - High temperature stimulates acetic acid accumulation and enhances the growth inhibition and ethanol production by Saccharomyces cerevisiae under fermenting conditions
AU - Woo, Ji Min
AU - Yang, Kyung Mi
AU - Kim, Sae Um
AU - Blank, Lars M.
AU - Park, Jin Byung
N1 - Funding Information:
Acknowledgments This study was supported by the Pioneer Research Center Program through the National Research Foundation of Korea funded by the Ministry of Education, Science, and Technology (No. 2009-0081512).
PY - 2014/7
Y1 - 2014/7
N2 - 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 in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.
AB - 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 in a decrease of the specific growth rate and ethanol production rate and, hence, are major determinants of cell stability and ethanol fermentation performance of S. cerevisiae at high temperatures. The results are discussed in the context of possible applications.
KW - Acetic acid stress
KW - Carbon metabolism
KW - Heat stress
KW - Oxidative stress
KW - Reactive oxygen species
KW - Saccharomyces cerevisiae
UR - http://www.scopus.com/inward/record.url?scp=84903594945&partnerID=8YFLogxK
U2 - 10.1007/s00253-014-5691-x
DO - 10.1007/s00253-014-5691-x
M3 - Article
AN - SCOPUS:84903594945
SN - 0175-7598
VL - 98
SP - 6085
EP - 6094
JO - Applied Microbiology and Biotechnology
JF - Applied Microbiology and Biotechnology
IS - 13
ER -