Salt and oxidative stress tolerance inDebaryomyces hanseniiandDebaryomyces fabryi

Abstract

We report the characterization of five strains belonging to the halotolerant highly related Debaryomyces hansenii/fabryi species. The analysis performed consisted in studying tolerance properties, membrane characteristics, and cation incell amounts. We have specifically investigated (1) tolerance to different chemicals, (2) tolerance to osmotic and salt stress, (3) tolerance and response to oxidative stress, (4) reactive oxygen species (ROS) content, (5) relative membrane potential, (6) cell volume, (7) K(+) and Na(+) ion content, and (8) membrane fluidity. Unexpectedly, no direct relationship was found between one particular strain, Na(+) content and its tolerance to NaCl or between its ROS content and its tolerance to H(2)O(2). Results show that, although in general, human origin D. fabryi strains were more resistant to oxidative stress and presented shorter doubling times and smaller cell volume than food isolated D. hansenii ones, strains belonging to the same species can be significantly different. Debaryomyces fabryi CBS1793 strain highlighted for its extremely tolerant behavior when exposed to the diverse stress factors studied.

XYLHencodes a xylose/H+symporter from the highly related yeast speciesDebaryomyces fabryiandDebaryomyces hansenii

“…Debaryomyces hansenii and D. fabryi are halotolerant/ halophilic yeasts (Neves et al, 1997;Prista et al, 1997;Mich an et al, 2012). The ability of wild strains from these species to live and multiply in the limit of salt solubility resides, namely, at the level of plasma membrane, which has substantially different properties as compared to S. cerevisiae (Kaneko et al, 1975;Tunblad-Johansson & Adler, 1987;Blagovic et al, 2001;Turk et al, 2007a,b).…”

Seasonal and plant‐dependent variations in diversity, abundance and stress tolerance of epiphytic yeasts in desert habitats

“…This result supports our previous observations from the qualitative experiment that showed that at certain high concentrations of NaCl, D. hansenii may have a special halotolerance mechanism that allows this strain to live in higher NaCl concentrations. It may also provide D. hansenii a higher tolerance ability to hyperosmotic environments than the same species isolated elsewhere (Aggarwal and Mondal, ; Michán et al ., ). This high osmotolerance ability might be significant in the survival of desert plants that grow in the salty soils during the dry summer.…”

Debaryomyces hansenii Strains from Valle De Los Pedroches Iberian Dry Meat Products: Isolation, Identification, Characterization, and Selection for Starter Cultures

“…(i) Toxic biogenic amines can be found in dry fermented sausages at relevant concentrations, and the amounts of these amines have been previously related to both temperature and NaCl in salami due to their influence on the lactic acid bacteria populations [45]. (ii) Although Debaryomyces has been reported as a halotolerant yeast, this character significantly varies between strains belonging to the same species [46]. (iii) Finally, D. hansenii is relatively sensitive to high temperatures.…”