caa a22 4500 465823300 CHVBK 20180323112141.0 cr unu---uuuuu 170327e19901101xx s 000 0 eng 10.1007/BF00166787 doi (NATIONALLICENCE)springer-10.1007/BF00166787 The role of an active transport mechanism in glycerol accumulation during osmoregulation by Zygosaccharomyces rouxii [Elektronische Daten] [Petrus van Zyl, Stephanus Kilian, Bernard Prior] Summary: At water activities (a w) of 0.998 (no osmoticum) and 0.960 a w(NaCl), the affinity (K m) of glycerol transport by Zygosaccharomyces rouxii was 25.6 and 6.4 mmol/l respectively. The maximum uptake rate (V max) was ca. 2.3 μmol/g/min at both a w's. However, at an a wof 0.960 using polyethylene glycol (PEG) 400 the K mand V max for glycerol transport increased to 61.1 mmol/l and 32.2 μmol/g per minute respectively. This suggests that different glycerol transport mechanisms operate during stress by the two osmotica. The addition of uncouplers (2,4-dinitrophenol or carbonylcyanide-m-chlorophenylhydrazine) resulted in the outflow of accumulated [14C]glycerol from Z. rouxii after on osmotic upshock indicating that an active transport mechanism was operative. The transport mechanism was specific for glycerol since other polyols (mannitol, meso-erythritol and arabitol) had no effect on the uptake rate. During upshock from 0.998 to 0.960 a w(NaCl), a transient increases in the rate of [14C]glycerol uptake was observed. However, if PEG 400 was used as osmoticum, the rate of glycerol uptake failed to increase. Springer-Verlag, 1990 van Zyl Petrus Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut Kilian Stephanus Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut Prior Bernard Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut Applied Microbiology and Biotechnology Springer-Verlag 34/2(1990-11-01), 231-235 0175-7598 34:2<231 1990 34 253 https://doi.org/10.1007/BF00166787 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00166787 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- van Zyl Petrus Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut NATIONALLICENCE 700 1- Kilian Stephanus Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut NATIONALLICENCE 700 1- Prior Bernard Department of Microbiology and Biochemistry, University of the Orange Free State, P. O. Box 339, 9300, Bloemfontein, Republic of South Africa aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer-Verlag 34/2(1990-11-01), 231-235 0175-7598 34:2<231 1990 34 253 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer