The phosphatase activity ofBacterium lactis aerogenes

Abstract

In the early stages of a grow cycle ofBact. lactis aerogenesin a glucose-ammonium sulphate medium the phosphatase activity of the cells rises to high levels from which it later declines, as though by progressive dilution with less active material. The decline is not prevented by maintenance of a constant pH, nor by periodic dilution with fresh medium so as to keep the cell count in unit volume near a steady mean. The pattern of variation depends on the medium : for example, amino acid additions lower the maximum, replacement of glucose by acetate prevents the decline, absence of molecular oxygen leads to a low activity throughout.