AIMS: This work aimed to identify the molecular mechanism that allows yeast cells to survive at low pH environments such as those of bioethanol fermentation. METHODS AND RESULTS: The industrial strain JP1 cells grown at pH 2 was evaluated by microarray analysis showing that most of the genes induced at low pH were part of the general stress response (GSR). Further, an acid-tolerant yeast mutant was isolated by adaptive selection that was prone to grow at low pH in inorganic but weak organic acid. It showed higher viability under acid-temperature synergistic treatment. However, it was deficient in some physiological aspects that are associated with defects in protein kinase A (PKA) pathway. Microarray analysis showed the induction of genes involved in inhibition of RNA and protein synthesis. CONCLUSIONS: The results point out that low pH activates GSR, mainly heat shock response, that is important for long-term cell survival and suggest that a fine regulatory PKA-dependent mechanism that might affect cell cycle in order to acquire tolerance to acid environment. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings might guide the construction of a high-fermentative stress-tolerant industrial yeast strain that can be used in complex industrial fermentation processes.
AIMS: This work aimed to identify the molecular mechanism that allows yeast cells to survive at low pH environments such as those of bioethanol fermentation. METHODS AND RESULTS: The industrial strain JP1 cells grown at pH 2 was evaluated by microarray analysis showing that most of the genes induced at low pH were part of the general stress response (GSR). Further, an acid-tolerant yeast mutant was isolated by adaptive selection that was prone to grow at low pH in inorganic but weak organic acid. It showed higher viability under acid-temperature synergistic treatment. However, it was deficient in some physiological aspects that are associated with defects in protein kinase A (PKA) pathway. Microarray analysis showed the induction of genes involved in inhibition of RNA and protein synthesis. CONCLUSIONS: The results point out that low pH activates GSR, mainly heat shock response, that is important for long-term cell survival and suggest that a fine regulatory PKA-dependent mechanism that might affect cell cycle in order to acquire tolerance to acid environment. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings might guide the construction of a high-fermentative stress-tolerant industrial yeast strain that can be used in complex industrial fermentation processes.
Authors: Elizabete A Covre; Lincon F L Silva; Reinaldo G Bastos; Sandra R Ceccato-Antonini Journal: World J Microbiol Biotechnol Date: 2019-08-20 Impact factor: 3.312
Authors: Chai-Jui Tsai; Kiran Aslam; Holli M Drendel; Josephat M Asiago; Kourtney M Goode; Lake N Paul; Jean-Christophe Rochet; Tony R Hazbun Journal: J Biol Chem Date: 2015-08-25 Impact factor: 5.157
Authors: Arun S Rajkumar; Guodong Liu; David Bergenholm; Dushica Arsovska; Mette Kristensen; Jens Nielsen; Michael K Jensen; Jay D Keasling Journal: Nucleic Acids Res Date: 2016-06-20 Impact factor: 16.971
Authors: Venkatachalam Narayanan; Violeta Sànchez I Nogué; Ed W J van Niel; Marie F Gorwa-Grauslund Journal: AMB Express Date: 2016-08-26 Impact factor: 3.298