The effect of two antifungal commercial formulations on the metabolism of a commercial Saccharomyces cerevisiae strain and their repercussion on fermentation evolution and phenylalanine catabolism

 Food Microbiology, 2020, 92, 103554

DOI: 10.1016/j.fm.2020.103554

The effect of two commercial formulations (incorporating mepanipyrim and tetraconazole as active substances) on the metabolism of Saccharomyces cerevisiae Lalvin T73™, growing on a synthetic grape must, and their influence on the alcoholic fermentation course and the biosynthesis of volatiles derived from phenylalanine catabolism was studied. No relevant effects were observed for mepanipyrim except for glycerol production. On the contrary, in the presence of tetraconazole many genes and some proteins related to cell cycle progression and mitosis were repressed. This fact could explain the lower biomass concentration and the lower sugar consumption registered for tetraconazole at the end of the study. However, the biomass-to-ethanol yield was higher in connection with the overexpression of the ADH1 gene. The presence of tetraconazole residues seems to accelerate the Ehrlich pathway. These results agree with the overexpression of several genes (BAT1, PDC1, PDC5, ADH1, SFA1, ATF2, PFK1, PFK2 and ARO3) and a higher abundance of two proteins (Gap1p and Atf2p) involved in this metabolic pathway.

Proteome changes in Garnacha Tintorera red grapes during post-harvest drying

LWT - Food Science and Technology, 69 (2016) 608–613

http://dx.doi.org/10.1016/j.lwt.2016.02.026

Fruit raisining is accompanied by changes in composition due to the joint action of water loss and modifying enzymes. Cell walls in grape berries form a barrier against diffusion of aromatic and polyphenolic compounds that influence wine quality. In this work, fresh and post-harvest dried grape samples of Vitis vinifera L. Garnacha Tintorera variety were compared in terms of proteome. The main change observed during raisining was over-expression from 14 to 47% of proteins involved in pathogen- and stress-resistance mechanisms, whereas metabolism-related proteins or those involved in the transcription and synthesis of other proteins decreased, respectively, from 43 to 27% and from 29 to 13%. These changes are important in the functional qualities and stability of the sweet wines obtained, since affect interactions with other macromolecules or metabolites.