SUMMARY: The influence of the temperature of incubation on the course of formic acid and gas production by cultures of a coliform organism growing in buffered and unbuffered peptone media was studied. The evidence suggests that at 30° and at 37° the onset of gas production is determined by the concentration of undissociated formic acid in the culture, but that a higher concentration of acid is required to elicit response at 37° than at 30°. Undissociated formic acid is toxic to the organism and it appears that gas is not produced in unbuffered glucose medium at 37° because the environmental conditions do not allow elaboration of hydrogenlyase before inhibitory conditions of pH value and formate concentration are attained.
DagleyS.,
DawesE.A.1953; The influence of pH value and aeration on the growth of Aerobacter aerogenes and Bacterium coli in defined media. J. gen. Microbiol 8:314
GaleE.F.,
EppsH.M.R.1942; The effect of the pH of the medium during growth on the enzymic activities of bacteria (Escherichia coli and Micrococcus lysodeikticus) and the biological significance of the changes produced. Biochem. J 36:600
PollockM.R.1945; The influence of temperature on the adaptation of ‘tetrathionase’ in washed suspensions of Bact. paratyphosum B. Brit. J. exp. Path 26:410