The Krebtri effect (glucose repression) - inhibition of respiration and activation of fermentation in yeast in a highly sugar medium. Named after the English biochemist Herbert Grace Krebtri.
As you know, oxygen inhibits fermentation ( Pasteur effect ). However, some races of yeast also produce ethanol under aerobic conditions, if the medium contains a sufficiently large amount of sugars. Since alcohol is poisonous for yeast, this slows down their reproduction and limits the productivity of yeast production . An increase in glucose concentration accelerates glycolysis, which leads to the formation of appreciable amounts of ATP along the path of substrate phosphorylation . This reduces the need for oxidative phosphorylation occurring in the ZTC through the electron transfer chain and, therefore, reduces oxygen consumption. The phenomenon is believed to have developed as a competition mechanism (due to the antiseptic nature of ethanol ) around the time that the first fruits on Earth fell from trees [1] .
Notes
- ↑ Thomson JM, Gaucher EA, Burgan MF, De Kee DW, Li T., Aris JP, Benner SA. Resurrecting ancestral alcohol dehydrogenases from yeast. (Eng.) // Nat. Genet. : journal. - 2005. - Vol. 37 , no. 6 . - P. 630-635 . - DOI : 10.1038 / ng1553 . - PMID 15864308 .
Literature
- Crabtree HG The carbohydrate metabolism of certain pathological overgrowths. (Eng.) // Biochem J. : journal. - 1928. - Vol. 22 , no. 5 . - P. 1289-1298 . - PMID 16744142 .