吲哚类杂环芳香族有机物在好氧和厌氧条件下的微生物降解途径

Aerobic and Anaerobic Degradation Pathways for N-heterocyclic Aromatic Compound Indole

用红树林的底泥通过富集培养得到在好氧或厌氧条件下能完全矿化吲哚的细菌 ,并对降解过程及中间代谢产物进行了鉴定。此研究中 ,吲哚化合物是培养液中的唯一碳和能量来源 ,而厌氧条件包括有产甲烷和硫酸盐还原。结果表明 ,不论在哪种条件下 ,吲哚降解过程分二步羰基化反应 ,分别发生在 2和 3位上 ,形成氧化吲哚和靛红。同时 ,1、2或 3位上的甲基替代使 1 甲基吲哚 ,2 甲基吲哚和 3 甲基吲哚的降解受到严重抑制。显然 ,杂环类芳香族化合物的代谢有其共同点 。

Both aerobic and anaerobic enrichment cultures were obtained from mangrove sediment using indole as the sole source of carbon and energy. Biochemical pathway of degradation was elucidated after identification of the degradation intermediates. Results showed that hydroxylation at 2 and 3 positions of the pyrrole ring is the initial step, resulting oxindole and isatin, respectively, regardless of the experimental conditions including aerobic and strictly anaerobic conditions (methanogenic and sulfate-reducing). Substitution of methyl group at 1,2 and 3 position on 1-methylindole, 2-methylindole and 3-methylindole inhibits initial microbial attack significantly. It is apparent that a common degradation pathway exists for N-heterocyclic aromatic compounds and the degradability is determined by the substitution groups and position.