Relationships between demethylase activity, formaldehyde and oxygen during incubation of Rhodococcus erythropolis with veratrate.

Relationships between demethylase activity, formaldehyde and oxygen were investigated. Demethylase activity was measured against the following substrates: veratric, vanillic, and isovanillic acids, as well as in the presence of guaiacol. The influence of ATP and GTP on demethylase activity was also checked. Demethylase activity was found to be dependent on the capability of the cells for endogenous oxygen uptake. In some cases ATP produced the opposite effect: instead of being taken up, oxygen was released, which suggested a reversibility of the demethylation reaction. Curiously enough, GTP demonstrated the same effect. Changes in enzyme activity were correlated with those occurring in the level of formaldehyde. The latter increased after addition of ATP, but decreased after addition of GTP.