Mechanisms underlying the halotolerant way of Debaryomyces hansenii.
The yeast Debaryomyces hansenii is usually found in salty environments such as the sea and salted food. It is capable of accumulating sodium without being intoxicated even when potassium is present at low concentration in the environment. In addition, sodium improves growth and protects D. hansenii in the presence of additional stress factors such as high temperature and extreme pH. An array of advantageous factors, as compared with Saccharomyces cerevisiae, is putatively involved in the increased halotolerance of D. hansenii: glycerol, the main compatible solute, is kept inside the cell by an active glycerol-Na+ symporter; potassium uptake is not inhibited by sodium; sodium protein targets in D. hansenii seem to be more resistant. The whole genome of D. hansenii has been sequenced and is now available at http://cbi.labri.fr/Genolevures/ and, so far, no genes specifically responsible for the halotolerant behaviour of D. hansenii have been found.
Prista
Catarina
C
Departamento de Botânica e Engenharia Biológica, Instituto Superior de Agronomia, 1349-017 Lisboa, Portugal. cprista@isa.utl.pt
Loureiro-Dias
Maria C
MC
Montiel
Vera
V
García
Raúl
R
Ramos
José
J
D001203:Ascomycota / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D001692:Biological Transport; D002414:Cations, Monovalent; D005990:Glycerol / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D011188:Potassium / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism
D002414:Cations, Monovalent; D012965:Sodium Chloride; D005990:Glycerol; D011188:Potassium