Unveiling the super tolerance of to oxidative stress: insights into the involvement of a catalase.

Yeast cells involved in fermentation processes face various stressors that disrupt redox homeostasis and cause cellular damage, making the study of oxidative stress mechanisms crucial. In this investigation, we isolated a resilient yeast strain, GXAS-CN, capable of thriving in the presence of high concentrations of HO. Transcriptomic analysis revealed the up-regulation of multiple antioxidant genes in response to oxidative stress. Deletion of the catalase gene significantly impacted HO-induced oxidative stress. Enzymatic analysis of recombinant Cat highlighted its highly efficient catalase activity and its essential role in mitigating HO. Furthermore, over-expression of Cat in improved oxidative resistance by reducing intracellular ROS accumulation. The presence of multiple stress-responsive transcription factor binding sites at the promoters of antioxidative genes indicates their regulation by different transcription factors. These findings demonstrate the potential of utilizing the remarkably tolerant GXAS-CN or enhancing the resistance of to improve the efficiency and cost-effectiveness of industrial fermentation processes.IMPORTANCEEnduring oxidative stress is a crucial trait for fermentation strains. The importance of this research is its capacity to advance industrial fermentation processes. Through an in-depth examination of the mechanisms behind the remarkable HO resistance in GXAS-CN and the successful genetic manipulation of this strain, we open the door to harnessing the potential of the catalase Cat for enhancing the oxidative stress resistance and performance of yeast strains. This pioneering achievement creates avenues for fine-tuning yeast strains for precise industrial applications, ultimately leading to more efficient and cost-effective biotechnological processes.