O-Demethylation of p-nitroanisole by Escherichia coli. Stimulation by phenobarbital

Intact cells of the bacterium Escherichia coli ATCC 11229, can convert p-nitroanisole into p-nitrophenol. The presence of phenobarbital in the culture medium during growth of the cells results in an inhibition of bacterial cell mass and an increased ability of the bacterial cell to carry out the O-demethylation reaction. There was a linear relationship between the amount of product formed and the bacterial cell mass in the incubation mixture. Varying the substrate concentration gave a concomitant change in activity, defined as the amount of product formed per mg of bacterial cell mass per 150 min. The optimum temperature for the production of p-nitrophenol by the stimulated cells was 33 degrees C; 7.0 was the pH optimum.