EFECTO DEL KCl Y LA VINAZA SOBRE EL NIVEL DE EXPRESIÓN DE MSN2 Y MSN4 EN Saccharomyces cerevisiae

MAZA, DÉBORA D.; MIRANDA LEIVA, FABIOLA L.; VIÑARTA, SILVANA C.; AYBAR, MANUEL J.

San Miguel de Tucumán

Jornada; Jornada Científicas- Asociación de Biología de Tucumán; 2016

Asociación de Biología de Tucumán

MSN2 and MSN4 transcription factors in stress conditions can form dimers and translocate to the nucleus where they bind to the STRE element of the promoter region of a large set of genes and activate their transcription in response to different types of stress (heat shock, oxidative or osmotic stress, nutrient starvation, etc.). In normal conditions, MSN2/4 do not participate in cell viability. Vinasse is a corrosive and contaminant industrial liquid residue of the sugar-alcohol industry dueto its high DBO, high potassium levels and dissolved organic matter. It contains average amounts of nitrogen compounds and phosphorus among others components. In this work we analyzed the effect of osmotic stress generated by KCl and vinasse on the growth and viability of S. cerevisiae ATCC 32051. Under these culture conditions, the levels of expressions MSN2/4 were evaluated at different times by semiquantitative RT-PCR. We observed that osmotic stress affected the growth of S. cerevisiae in cultures with vinasse or KCl compared to control. The yeast cells grown in a medium with KCl showed greater osmotic tolerance than the cells in medium with vinasse. As the concentration of KCl or vinasse in the medium increased, the adaptation time period increased also, and a delay in the growth phases was observed. The expression level of MSN2/4 varied according to the time and conditions evaluated. These results suggest that MSN2/4 play a key role in osmotic stress response and that their expression, which is necessary since the initiation of the culture, is required for long time periods to maintain viability under adverse culture conditions.