Growth of cucumber cells in media with lactose or milk whey as carbon source.

Lactose utilisation by cucumber cell suspension cultures starts only after a long lag phase and is accompanied by an increase of an extracellular lactosespecific β-galactosidase activity. Supplementing the lactose medium with sucrose shortens the lag phase.Milk whey permeate seems to contain a factor(s) which inhibits lactose utilisation. After supplementing the medium with sucrose or its hydrolysis products, growth and substrate utilisation is as efficient as in Murashige and Skoog medium. Galactose also induces growth, but growth and substrate utilisation are slower. In whey medium, supplemented with sucrose, the extracellular β-galactosidase activity again accompanies growth induction.