PROTON-DEPENDENT KINETICS OF CITRATE UPTAKE IN GROWING CELLS OF LACTOCOCCUS-LACTIS SUBSP LACTIS BV DIACETYLACTIS

The kinetic analysis of citrate uptake in growing cells of Lactococcus lactis subsp, lactis biovar, diacetylactis identified a proton-dependent transport and suggested the divalent anionic species as the form of citrate transported across cell membranes. The reaction followed Michaelis-Menten kinetics for a two-substrate reaction. The limiting steps were the formation of the ternary complex and the rate of transport. Temperature modified the activity of the permease, increasing the uptake rate.