1953 Volume 27 Issue 5 Pages 260-264
(1) A few oxidative natures of 2-hydroxyphenylacetic acid (2-OH-PAA) were examined manometrically. The oxidative activity of 2-OH-PAA was nearly constant between pH 5 and 8; it was not inhibited below the pH (5.6) at which the oxidative activity of phenylacetic acid (PAA) fell off.
(2) For the oxidation of 2-OH-PAA, the optimal concentration of the substrate was above 0.03M; the oxidative activity of 2-OH-PAA was not inhibited above the concentration (0.03M) at which the oxidative activity of PAA was poisoned.
(3) When 1 molecule of 2-OH-PAA was oxidized, 4-4.5 molecules of oxygen were consumed and 3_??_4 molecules of carbon dioxide were excreted. The amount of oxygen consumption per 1 melecule of 2-OH-FAA was less than that of PAA by about half a molecule, and the amount of carbon dioxide output was equal to that of PAA.
(4) By means of Gibbs' indophenol reaction, the change of 2-OH-PAA content was examined in the synthetic medium containing PAA. 2-OH-PAA appeared according to the PAA metabolism, and its maximum content was achieved at about 130 hour culture period, and afterwards, it disappeared gradually with the progress of cultivation. In case of the medium containing 2-OH-PAA instead of PAA, the rate of 2-OH-PAA metabolism was slower than that of PAA metabolism.
(5) The penicillin G formation was examined on the cultures to which had been added PAA and 2-OH-PAA individually as precursor. In case of 2-OH-PAA, the corresponding new biosynthetic penicillin was not found, but it acted as a precursor of penicillin G. From this reason, it was presumed that the enzymatic conversion from PAA to 2-OH-PAA was a reversible reaction.
