Yeast cells physiology after high hydrostatic pressure stress

International Conference on Cytopathology

August 31-September 02, 2015 Toronto, Canada

Patricia M B Fernandes

Universidade Federal do Espirito Santo, Brazil

Posters-Accepted Abstracts: J Cytol Histol

Abstract :

High hydrostatic pressure (HHP) is a stress that exerts broad effects on microorganisms with characteristics similar to those of common environmental stresses. Cells subjected to HHP shows alteration in their macromolecule structure. Physiological and biochemical processes are also modified to maintain cell viability. Changes in Saccharomyces cerevisiae cells physiology subjected to HHP were observed by flow cytometer using ethidium bromide (BE), bis-oxonol (BOX) and propidiumiodide (PI) as fluorescent markers. The results indicated the feasibility on the use of flow cytometry based on optical data from the light scattering as a relative counting technique but not as an absolute technique due to the presence of budding cells. SYTO 9 and PI fluorophores were suitable to analyze cell viability showing strong correlation with agar-plating technique. HHP caused cell size and cell complexity reduction. An increase in cellular stress as evidenced by membrane depolarization using PI marker was noticed in pressures above 50 MPa. Moreover, there was an increase in cell damagein HHP from 150 MPa that impaired life. Cell physiology analysis performed with BOX and PI fluorophores provided data on the percentage of dead, live or damaged cells favorable for discriminating two subpopulations: Live-healthy cells and live-stressed cells. Flow cytometry thus provided detailed data on the effect of HHP when compared to traditional techniques for cell damage analysis by providing information on cell viability on morphological and physiological changes through fast and accurate readings.

Biography :

Email: patricia.fernandes@ufes.br