Degradation of phenols by intact cells and cell-free preparations of Trichosporon cutaneum

TLDR: Results of studies with intact cells and cell-free preparations indicated that not only phenol but also resorcinol, quinol and catechol were further hydroxylated prior to ring fission.

Abstract: A yeast strain, enriched and isolated from soil using phenol as major carbon source, was identified as Trichosporon cutaneum. After growth on phenol washed cell suspensions of the organism oxidized phenol and some phenol derivatives without delay, others after varying lag periods. Cell-free preparations from the yeast strain were capable of hydroxylating various phenols as judged by a substrate- and NADPH-dependent oxygen uptake. Certain properties and the cofactor requirement of this hydroxylating system were investigated. Diphenols were hydroxylated at rates considerably higher than monophenols. Mono-halogen substituted phenols were hydroxylated at rates comparable to that of phenol hydroxylation. The relative hydroxylating activities with respect to different phenol derivatives were markedly changed after 3–5 weeks' storage, thus indicating the presence of several hydroxylating enzymes. The cell-free preparations also contained the enzyme catechol 1,2-oxygenase. Results of studies with intact cells and cell-free preparations indicated that not only phenol but also resorcinol, quinol and catechol were further hydroxylated prior to ring fission. Catechol when supplied as substrate of catechol 1,2-oxygenase preparations, was oxidized by the “ortho type” of ring fission. The enzyme involved has broad substrate specificity.