Glutathione is involved in physiological response of Candida utilis to acid stress.
Candida utilis often encounters an acid stress environment when hexose and pentose are metabolized to produce acidic bio-based materials. In order to reveal the physiological role of glutathione (GSH) in the response of cells of this industrial yeast to acid stress, an efficient GSH-producing strain of C. utilis CCTCC M 209298 and its mutants deficient in GSH biosynthesis, C. utilis Δgsh1 and Δgsh2, were used in this study. A long-term mild acid challenge (pH 3.5 for 6 h) and a short-term severe acid challenge (pH 1.5 for 2 h) were conducted at 18 h during batch culture of the yeast to generate acid stress conditions. Differences in the physiological performances among the three strains under acid stress were analyzed in terms of GSH biosynthesis and distribution; intracellular pH; activities of γ-glutamylcysteine synthetase, catalase, and superoxide dismutase; intracellular ATP level; and ATP/ADP ratio. The intracellular GSH content of the yeast was found to be correlated with changes in physiological data, and a higher intracellular GSH content led to greater relief of cells to the acid stress, suggesting that GSH may be involved in protecting C. utilis against acid stress. Results presented in this manuscript not only increase our understanding of the impact of GSH on the physiology of C. utilis but also help us to comprehend the mechanism underlying the response to acid stress of eukaryotic microorganisms.
School of Biology and Basic Medical Sciences, Soochow University, Suzhou, 215123, People's Republic of China.
Da-Hui
DH
Wang
School of Biology and Basic Medical Sciences, Soochow University, Suzhou, 215123, People's Republic of China.
Jun-Li
JL
Zhang
School of Biology and Basic Medical Sciences, Soochow University, Suzhou, 215123, People's Republic of China.
Ying-Ying
YY
Dong
School of Biology and Basic Medical Sciences, Soochow University, Suzhou, 215123, People's Republic of China. weigy@suda.edu.cn.
Gong-Yuan
GY
Wei
School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, 215500, People's Republic of China. qibin65@126.com.
Bin
B
Qi
D000143:Acids / Q000633:toxicity*; D002175:Candida / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017353:Gene Deletion; D005978:Glutathione / Q000378:metabolism*; D013312:Stress, Physiological
D000143:Acids; D005978:Glutathione
ATP; Acid stress; Candida utilis; Glutathione; Intracellular pH; γ-Glutamylcysteine synthetase