[Demonstration of 2 phosphate transport systems in Candida tropicalis]

Candida tropicalis has two phosphate transport systems, one of which is constitutive and has a low affinity for its substrate (Kmapp 1.2.10(-3) M). The other one characterized by a high affinity for H2PO4- (Kmapp = 4.5.10(-6) M) appears only under phosphate starvation conditions. The regulation of the latter would act on the one hand on the synthesis of binding proteins for P1 (repression-derepression) and on the other on the activation or inactivation of the carriers.