Journal
YEAST
Volume 33, Issue 8, Pages 355-363Publisher
WILEY
DOI: 10.1002/yea.3154
Keywords
Saccharomyces cerevisiae; proline; ethanol stress; reactive oxygen species
Categories
Funding
- Programme for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN)
- Grants-in-Aid for Scientific Research [26111009] Funding Source: KAKEN
Ask authors/readers for more resources
During fermentation processes, Saccharomyces cerevisiae cells are exposed to multiple stresses, including a high concentration of ethanol that represents toxicity through intracellular reactive oxygen species (ROS) generation. We previously reported that proline protected yeast cells from damage caused by various stresses, such as freezing and ethanol. As an anti-oxidant, proline is suggested to scavenge intracellular ROS. In this study, we examined the role of intracellular proline during ethanol treatment in S. cerevisiae strains that accumulate different concentrations of proline. When cultured in YPD medium, there was a significant accumulation of proline in the put1 mutant strain, which is deficient in proline oxidase, in the stationary phase. Expression of the mutant PRO1 gene, which encodes the -glutamyl kinase variant (Asp154Asn or Ile150Thr) with desensitization to feedback inhibition by proline in the put1 mutant strain, showed a prominent increase in proline content as compared with that of the wild-type strain. The oxidation level was clearly increased in wild-type cells after exposure to ethanol, indicating that the generation of ROS occurred. Interestingly, proline accumulation significantly reduces the ROS level and increases the survival rate of yeast cells in the stationary phase under ethanol stress conditions. However, there was not a clear correlation between proline content and survival rate in yeast cells. An appropriate level of intracellular proline in yeast might be important for its stress-protective effect. Hence, the engineering of proline metabolism could be promising for breeding stress-tolerant industrial yeast strains. Copyright (c) 2016 John Wiley & Sons, Ltd.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available