Schwarz Luisa Vivian, Sandri Fernanda Knaach, Scariot Fernando, Delamare Ana Paula Longaray, Valera Maria Jose, Carrau Francisco, Echeverrigaray Sergio
Institute of Biotechnology, University of Caxias do Sul (UCS), Caxias do Sul, Rio Grande do Sul, Brazil.
Enology and Fermentation Biotechnology Area, Departamento Ciencia y Tecnología Alimentos, Facultad de Química, Universidad de la Republica, Montevideo, Uruguay.
Yeast. 2023 Dec;40(12):640-650. doi: 10.1002/yea.3911. Epub 2023 Nov 23.
Yeasts have been widely used as a model to better understand cell cycle mechanisms and how nutritional and genetic factors can impact cell cycle progression. While nitrogen scarcity is well known to modulate cell cycle progression, the relevance of nitrogen excess for microorganisms has been overlooked. In our previous work, we observed an absence of proper entry into the quiescent state in Hanseniaspora vineae and identified a potential link between this behavior and nitrogen availability. Furthermore, the Hanseniaspora genus has gained attention due to a significant loss of genes associated with DNA repair and cell cycle. Thus, the aim of our study was to investigate the effects of varying nitrogen concentrations on H. vineae's cell cycle progression. Our findings demonstrated that nitrogen excess, regardless of the source, disrupts cell cycle progression and induces G2/M arrest in H. vineae after reaching the stationary phase. Additionally, we observed a viability decline in H. vineae cells in an ammonium-dependent manner, accompanied by increased production of reactive oxygen species, mitochondrial hyperpolarization, intracellular acidification, and DNA fragmentation. Overall, our study highlights the events of the cell cycle arrest in H. vineae induced by nitrogen excess and attempts to elucidate the possible mechanism triggering this absence of proper entry into the quiescent state.
