Na+-mediated piezoprotection in Rhodotorula rubra

• Published in: Extremophiles : life under extreme conditions 2003-12, Vol.7 (6), p.499-504
• Main Authors: AERTSEN, Abram, MASSCHALCK, Barbara, WUYTACK, Elke Y, MICHIELS, Chris W
• Format: Article
• Language: English
• Subjects: Acidification; Apoptosis; Biodegradation of pollutants; Biological and medical sciences; Biotechnology; Cell Membrane - metabolism; Cells, Cultured; Environment and pollution; Forest management; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forestry; Fundamental and applied biological sciences. Psychology; High pressure; Hydrogen-Ion Concentration; Inactivation; Industrial applications and implications. Economical aspects; Lithium - metabolism; Potassium - metabolism; Reproducibility of Results; Rhodotorula - genetics; Rhodotorula - metabolism; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Schizosaccharomyces - genetics; Schizosaccharomyces - metabolism; Sodium - metabolism; Sodium-Hydrogen Exchangers - metabolism; Space life sciences; Species Specificity; Yeasts
• ISSN: 1431-0651; 1433-4909
• DOI: 10.1007/s00792-003-0350-7

Sodium concentrations as low as 2 mM exerted a significant protective effect on the high-pressure inactivation (160-210 MPa) of Rhodotorula rubra at pH 6.5, but not on two other yeasts tested (Schizosaccharomyces pombe and Saccharomyces cerevisiae). A piezoprotective effect of similar magnitude was observed with Li+ (2 and 10 mM), and at elevated pH (8.0-9.0), but no effect was seen with K+, Ca2+, Mg2+, Mn2+, or NH4(+). Intracellular Na+ levels in cells exposed to low concentrations of Na+ or to pH 8.0-9.0 provided evidence for the involvement of a plasma membrane Na+/H+ antiporter and a correlation between intracellular Na+ levels and pressure resistance. The results support the hypothesis that moderate high pressure causes indirect cell death in R. rubra by inducing cytosolic acidification.