Regulation of Hexose Transport in Chlorella vulgaris

Abstract

Of nine species of unicellular algae tested, Chlorella vulgaris showed the highest inducibility for an active hexose transport system. Whereas the rate of uptake in all other species was increased by induction less than 5-fold, it was increased more than 400-fold in one strain of C. vulgaris. With glucose as inducer, the minimum time necessary to synthesize inducible proteins of the transport system was 15 minutes. The Km for induction with glucose is 5 μm and with 6-deoxyglucose 1 mm. The inducing sugars have to penetrate the cells to be effective.