The metabolism of cresols by species of Pseudomonas

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Abstract
A comparison of rates of oxidation of various compounds by whole cells indicated that protocatechuate was a reaction intermediate when a non-fluorescent species of Pseudomonas oxidized p-cresol. In contrast, a fluorescent Pseudomonas oxidized 3-methylcatechol and 4-methylcatechol when grown with p-cresol, but did not oxidize protocatechuate. Heat-treated extracts of the fluorescent Pseudomonas oxidized catechol, 3-methylcatechol and 4-methylcatechol to ring-fission products, the spectroscoplc properties of which were recorded. Rates of enzymlc degradation of these products were also measured. Acetic acid and formic acid were obtained by the action of a Sephadex-treated extract on 3-methylcatechol and 4-methylcatechol respectively. In each case 0.8 mol. of the carboxylic acid was formed from 1.0 mol. of substrate. Dlalyzed extracts converted 3-methylcatechol into acetaldehyde and pyruvate, with 4-hydroxy-2-oxovalerate as a reaction Intermediate. 4-Methylcatechol was converted first into 4-hydroxy-2-oxohexanoate and then into propionaldehyde and pyruvate. The ring-fission product of catechol was formed from phenol by a fluorescent Pseudomonas, that of 3-methylcatechol was formed from o-cresol and m-cresol, and the rlng-fisslon product of 4-methylcatechol was given from p-cresol. Propionate was readily oxidized by these cells after growth with.p-cresol, but this compound was not attacked when phenol, o-cresol or m-cresol served as source of carbon. Cell extracts appeared to attack only one enantlomer of synthetic 4-hydroxy-2-oxo-hexanoate.