Effect of the SNF1 Deletion in the Glycolytic Pathway of Saccharomyces cerevisiae Grown at 1% Glucose

Abstract

The alcoholic fermentation is an amphibolic process that allows the formation of ATP at substrate‐level, keeps active the glycolysis through re‐oxidation of NADH, and generate metabolites of biotechnological interest. Saccharomyces cerevisiae is a positive Crabtree, which performs the alcoholic fermentation in oxygen presence, increasing the glycolytic flux accompanied by repression of respiration. However, the molecular mechanism of the Crabtree effect is still not clear. The sucrose non‐fermenting protein‐1 (Snf1p) is a cellular energy sensor that modulates the switch between respiration and alcoholic fermentation. Therefore, Snf1p could be a key piece in the molecular puzzle of the alcoholic fermentation related to the Crabtree effect. For this reason, this work aimed to determine whether the deletion in SNF1 gene affects the alcoholic fermentation at 1% glucose. For this purpose, the BY4742 genetic background was used and its mutant in the SNF1 gene. In this way, it was found: 1) that the absence of SNF1 gene affects growth. 2) A decrease in extracellular acidification rate in SNF1 mutant. 3) NADH/NAD ratio does not have any change in the strains. However, the amount NAD(P)H showed an increase in SNF1 mutant. 4) Transcription levels of HXK2 gene displayed an increase in SNF1 mutant; while transcription levels of PFK1 gene decrease. 5) The basal respiration and the maximum respiratory capacity diminished in SNF1 mutant. All data suggest that deletion in SNF1 gene favors the formation of the anabolic species NADPH, probably by a transcriptional regulation of glycolysis, not observing an effect in the alcoholic fermentation.Support or Funding InformationPRODEP partially funded this work (project number: ITESCH‐EXB‐002).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.