Department of Environmental Science, School of Biological and Environmental Sciences, Rutgers University, New Brunswick, New Jersey, USA.
Department of Environmental Science, School of Biological and Environmental Sciences, Rutgers University, New Brunswick, New Jersey, USA.
Adv Appl Microbiol. 2014;88:167-203. doi: 10.1016/B978-0-12-800260-5.00005-X.
Aromatic compounds are a major component of the global carbon pool and include a diverse range of compounds such as humic acid, lignin, amino acids, and industrial contaminants. Due to the prevalence of aromatic compounds in the environment, aerobic and anaerobic microorganisms have evolved mechanisms by which to metabolize that available carbon. Less well understood are the anaerobic pathways. We now know that anaerobic metabolism of a variety of monoaromatic compounds can be initiated in a number of different ways, and a key metabolite for these pathways is benzoyl-CoA. Chemicals can have different upstream anaerobic degradation pathways yet can still be assessed by targeting the downstream benzoyl-CoA pathway. In this pathway, we propose that the ring opening hydrolase, encoded by the bamA gene, is especially useful because, in contrast to the benzoyl-CoA reductase, it is detected under a number of respiratory settings, including denitrifying, iron-reducing, sulfate-reducing, and fermentative conditions, and has a wide distribution in the environment. This review examines the bamA gene in enrichment cultures and environmental DNA extracts to consider whether it can be used as a biomarker for anaerobic aromatic degradation. Given the number of potential upstream inputs from natural and man-made monoaromatic compounds, the benzoyl-CoA pathway and the bamA gene in particular may play an important role in the global carbon cycle that has thus far been overlooked.
芳香族化合物是全球碳库的主要组成部分，包括各种化合物，如腐殖酸、木质素、氨基酸和工业污染物。由于芳香族化合物在环境中普遍存在，好氧和厌氧微生物已经进化出了代谢可用碳的机制。而对于厌氧途径则了解较少。我们现在知道，许多单芳香族化合物的厌氧代谢可以通过多种不同的方式启动，而这些途径的关键代谢物是苯甲酰辅酶 A。尽管化学物质可能具有不同的上游厌氧降解途径，但仍可以通过靶向下游的苯甲酰辅酶 A 途径来进行评估。在这条途径中，我们提出，由 bamA 基因编码的环开裂水解酶特别有用，因为与苯甲酰辅酶 A 还原酶不同，它在许多呼吸条件下都能被检测到，包括反硝化、铁还原、硫酸盐还原和发酵条件，并且在环境中广泛分布。本综述检查了富集培养物和环境 DNA 提取物中的 bamA 基因，以考虑它是否可以用作厌氧芳香族降解的生物标志物。鉴于天然和人工单芳香族化合物的潜在上游输入数量众多，苯甲酰辅酶 A 途径和 bamA 基因可能特别在迄今为止被忽视的全球碳循环中发挥着重要作用。
