Open AccessHigh capacity xylose transport in Candida intermedia PYCC 4715
Author(s) -
Gárdonyi Márk,
Österberg Måns,
Rodrigues Carla,
SpencerMartins Isabel,
HahnHägerdal Bärbel
Publication year - 2003
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2003.tb00137.x
Subject(s) - xylose , xylose metabolism , biochemistry , yeast , biology , symporter , glucose transporter , transporter , fermentation , microbiology and biotechnology , gene , insulin
Xylose‐utilising yeasts were screened to identify strains with high xylose transport capacity. Among the fastest‐growing strains in xylose medium, Candida intermedia PYCC 4715 showed the highest xylose transport capacity. Maximal specific growth rate was the same in glucose and xylose media ( μ max =0.5 h −1 , 30°C). Xylose transport showed biphasic kinetics when cells were grown in either xylose‐ or glucose‐limited culture. The high‐affinity xylose/proton symport system ( K m =0.2 mM, V max =7.5 mmol h −1 g −1 ) was more repressed by glucose than by xylose. The less specific low‐affinity transport system ( K =50 mM, V max =11 mmol h −1 g −1 ) appeared to operate through a facilitated‐diffusion mechanism and was expressed constitutively. Inhibition experiments showed that glucose is a substrate of both xylose transport systems.