THE GLUCOSE TRANSPORT SYSTEM OFAMPHORA COFFEAEFORMIS(BACILLARIOPHYCEAE)1

Abstract

Amphora coffeaeformis(Ag.) Kütz. var.perpusilla(Grun.) Cleve took up glucose by an inducible transport system. The system was induced byd‐fructose,d‐mannose, as well as glucose. Somed‐pentoses also induced a glucose uptake system but it may not be the same one as that induced by hexose.d‐fructose,d‐mannose and 2‐deoxy‐d‐glucose inhibited 2 mM glucose uptake at equimolar concentration, butd‐pentoses did not. The uptake system decayed inca.5 h in the absence of glucose. The half‐saturation constant for uptake,K₈wasca.0.1 mM glucose with a maximum uptake rate,V_max=0.4 nmol/10⁶cells‐min⁻¹.