Journal of Microbiology

Roles of the meta- and the ortho-Cleavage Pathways for the Efficient Utilization of Aromatic Hydrocarbons by Sphingomonas yanoikuyae B1: Jeongmin Song , Junghee Sung , Young Min Kim , Gerben J. Zylstra , Eungbin Kim; J. Microbiol. 2000;38(4):245-249.

Abstract: Catabolic pathways for the degradation of various aromatics by Sphingomonas yanoikuyae B1 are intertwined, joining at the level of substituted benzoates, which are further degraded via ring cleavage reactions. The mutant strain EK497, which was constructed by deleting a large DNA region containing most of the genes for biphenyl, naphthalene, m-xylene, and m-toluate degradation, was unable to grow on all of the aromatics tested except for benzoate as the sole source of carbon and energy. S. yanoikuyae EK497 was found to possess only catechol ortho-ring cleavage activity due to deletion of the genes for the meta-cleavage pathway. Wild-type S. yanoikuyae B1 grown on benzoate has both catechol ortho-and meta-cleavage activity. However, m-xylene and m-toluate, which are metabolized through methylbenzoate, and biphenyl, which is metabolized through benzoate, induce only the meta-cleavage pathway, suggesting the presence of a substrate-dependent induction mechanism.

Three Separate Pathways for the Initial Oxidation of Limonene, Biphenyl, and Phenol by Rhodococcus sp. Strain T104: Dockyu Kim , Min Jung Park , Sung-Cheol Koh , Jae-Seong So , Eungbin Kim; J. Microbiol. 2002;40(1):86-89.

Abstract: Rhodococcus sp. strain T104, which is able to grow on either biphenyl or limonene, was found to utilize phenol as sole carbon and energy sources. Furthermore, T104 was positively identified to possess three separate pathways for the degradation of limonene, phenol, and biphenyl. The fact that biphenyl and limonene induced almost the same amount of catechol 1,2-dioxygenase activity indicates that limonene can induce both upper and lower pathways for biphenyl degradation by T104.

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