The adaptability of glucozymase and galactozymase in Bacterium coli

Abstract

Washed suspensions of Bact. coli ferment glucose at a rate which varies according to the conditions in which the organism has been grown. The rate of glycolysis (Qglucose = y glucose fermented/mg. Bact. coli per H2) is doubled on passing from aerobic to anaerobic conditions of growth and again doubled by the addition of 1% glucose to the medium. Galactose is fermented at a rate as com- pared with glucose when the organism is grown without the specific substrate (Qglucose = 250 Qgalactos =20). The Qgalactose is not raised by adding glucose to the medium but is increased 40-fold by 1% galactose; this increase is not reached when glucose and galactose together amount to 1%. Adaptation to galactose is in the case of this organism accompanied by growth. No evidence of adaptation in the presence of galactose can be shown in the absence of multiplication, and the increase in Qgalactose is proportional to the number of cells which have multiplied in the presence of the specific substrate.