吲哚的微生物代谢及其作为新型信号分子的研究进展

吲哚，又称2,3-苯并吡咯，广泛应用于化工、医药、染料等行业，是工业上重要的前体物质，但其释放到环境中也是一种典型的氮杂环污染物。同时，作为一种常见的微生物代谢产物，自然界中无时无刻不发生着吲哚的合成—转化—降解过程。吲哚对微生物生物膜的形成、运动能力、毒性、质粒稳定性及抗生素抗性等多种生物功能有显著影响。因此，吲哚也被认为是新型且具有多功能的种间及跨界信号分子，在微生物生理学和动物行为学等领域发挥了重要作用。研究微生物介导的吲哚代谢机制，阐明其生物学功能的基础，是揭示吲哚在自然环境中的行为归趋和生态学意义的关键。本文系统地总结吲哚代谢的微生物资源及途径，介绍其作为信号分子的重要功能，并对有关吲哚-微生物相互作用的研究进行总结，以期为揭示复杂环境中吲哚生物代谢机制提供重要的理论参考。

Microbial metabolism of indole and its role as a novel signal molecule: a review

Indole, also known as 2,3-benzopyrrole, is a typical nitrogen heterocyclic pollutant compound that is widely used in the chemical, pharmaceutical, dye and other industries. Meanwhile, it is a representative microbial metabolite in natural habitats and can be synthesized, transformed and degraded all the time. Besides, indole has a significant effect on various biological functions, such as the formation of microbial biofilms, motility, toxicity, plasmid stability, and even antibiotic resistance of the microbes. Thus, indole has been considered as a new and multifunctional inter-specific and inter-kingdom signaling molecule, playing an important role in bacterial physiology and animal behavior. Therefore, studying the mechanism of indole metabolism mediated by microorganisms as well as elucidating the basis of biological functions might be the key to reveal its fate and ecological significance to natural environment. In this review, the microbial resources and pathways of indole metabolism are systematically summarized. The important functions as signal molecules are also introduced, and the interactions of indoles-microorganisms are illustrated. The review provides important theoretical reference for revealing the metabolic mechanism of indole in complex environments.