Hanseniaspora vineae: ciclo celular e efeito da concentração de nitrogênio em sistema aeróbico e em fermentação

Abstract

Abstract: Yeasts have been widely used in wine production and as a model to better understand fundamental biochemical, molecular, and cellular processes. The genus Hanseniaspora has gained visibility in oenology due to its ability to enhance wine aromatic profiles and its unique loss of dozens of genes involved in DNA damage response and cell cycle, which are widely conserved across various living organisms. In this context, this study prioritized evaluating the effects of different nitrogen concentrations, especially ammonium, on the cell cycle and metabolism of representatives of the Hanseniaspora genus, with an emphasis on H. vineae in aerobic systems and fermentations. When comparing the cell cycle progression of different Hanseniaspora species, only H. vineae failed to enter quiescence (G0 phase of the cell cycle) after the stationary phase evaluating the cell cycle progression of H. vineae in the presence of different nitrogen concentrations (50 mg/L, 100 mg/L, and 500 mg/L YAN) in an aerobic and discontinuous system, it was found that high nitrogen concentrations are the primary stimulus for the absence of entry into quiescence during the stationary phase. This was also simultaneously associated with a decrease in cell viability, an increase in the production of reactive oxygen species, mitochondrial hyperpolarization, intracellular acidification, and DNA damage. Furthermore, in fermentations using (75 mg/L, 150 mg/L, and 300 mg/L YAN), the same behavior regarding the cell cycle and decreased viability was observed with increasing nitrogen levels. However, there was no clear relationship between the production of aromatic compounds by H. vineae and its behavior in terms of cell cycle progression. In general, the observations described in this study highlight the events of cell cycle arrest in H. vineae induced by excess nitrogen and attempt to elucidate the possible mechanism that triggers this lack of proper entry into the quiescent state, both in aerobic systems and during fermentation. This contributes to a better understanding of the Hanseniaspora genus, especially the H. vineae species, and expands the possibilities for the use of nonSaccharomyces yeasts in the study of fundamental cellular processes. [resumo fornecido pelo autor]