Accumulation of glycerol by the heterobasidiomycetous yeast Rhodosporidium sphaerocarpum in response to external hypertonicity due to NaCl

Abstract The heterobasidiomycetous yeast Rhodosporidium sphaerocarpum isolated from the Antarctic Ocean and a saltpan, showed marked tolerance to high concentrations of NaCl in the growth medium. This yeast accumulated glycerol as a major osmoregulator, as well as Na⁺ and Cl⁻, in response to changes in the concentration of NaCl in the external medium. The low levels of another cellular polyol, xylitol, did not respond to changes in the external medium.