Examination of the effect of HOG1 deletion on glucose fermentation in Saccharomyces cerevisiae.

HOG1 encodes a mitogen-activated protein kinase in Saccharomyces cerevisiae and plays a crucial role in the high osmolarity glycerol pathway during the osmotic stress response. HOG1 loss improves glycerol utilization in yeast; however, its effects on the growth and fermentation profiles during glucose cultivation remain unexplored. Therefore, this study aimed to explore the effects of HOG1 deletion on glucose fermentation. HOG1 deletion led to enhanced glucose utilization and ethanol production by 14.30 % compared to the wild-type strain. Glycerol, acetate, and 2,3-butanediol levels were decreased in the Δhog1 strain. The loss of HOG1 function prevented resistance to high osmotic pressure resulting from high initial glucose fermentation; resistance was restored and enhanced by intermittent feeding. Key genes in central metabolism were deleted to investigate metabolic shifts further. PDC1 and ADH1 deletion induced NADH accumulation and redox imbalance, resulting in GPD2 primarily driving glycerol production. Elucidating the role of HOG1 in glucose fermentation offers novel insights into yeast physiology, with potential applications in biotechnology and industrial processes.