Carmona Manuel, Zamarro María Teresa, Blázquez Blas, Durante-Rodríguez Gonzalo, Juárez Javier F, Valderrama J Andrés, Barragán María J L, García José Luis, Díaz Eduardo
Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain.
Microbiol Mol Biol Rev. 2009 Mar;73(1):71-133. doi: 10.1128/MMBR.00021-08.
Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach.
芳香族化合物是自然界中分布最广泛的有机化合物类别之一，大量的外源化合物也属于这一类化合物。由于许多含有大量芳香族化合物的生境往往是缺氧的，因此微生物对芳香族化合物的厌氧分解代谢在生物地球化学循环和生物圈的可持续发展中变得至关重要。兼性或专性厌氧细菌对芳香族化合物的矿化作用可以与以多种电子受体进行的厌氧呼吸以及发酵和无氧光合作用相耦合。由于电子接受系统的氧化还原电位决定了降解策略，厌氧芳香族化合物降解菌之间存在广泛的生化多样性。然而，所有这些过程的遗传决定因素及其调控机制的研究却少得多。本综述重点关注最近的研究发现，即标准分子生物学方法与新的高通量技术（如基因组测序、转录组学、蛋白质组学和宏基因组学）在厌氧芳香族化合物降解途径的遗传学、调控、生态生理学和进化方面所提供的信息。这些研究表明，芳香族化合物的厌氧分解代谢比以前认为的更加多样和广泛，与厌氧条件下使用芳香族化合物相关的复杂代谢和应激程序也开始被揭示。基于具有前所未有的酶和途径以及新的代谢能力的厌氧生物转化过程，以及合成生物学中具有巨大生物技术潜力的新型调控回路和分解代谢网络的设计，现在都可以实现。
