Anaerobic biodegradation of hydrocarbons mainly related to petroleum can be observed in numerous natural and anthropogenically overprinted environments. While microbiological and chemical tracers are used to study the development of such habitats, not much is known about the impact of particular bacteria on the system. Therefore, we used Aromatoleum sp. HxN1, an n-alkane-utilizing betaproteobacterium capable of degrading crude oil constituents under strictly anoxic conditions, as a model organism to examine its potential to release carboxylic acid metabolites into the surrounding environment. We conducted cultivation experiments with pure substrates, as well as with crude oil, and demonstrated that intermediates of catabolic pathways were highly abundant in the exometabolome. Strikingly, the metabolites found in highest concentrations in the cell-free culture supernatant of strain HxN1 grown with crude oil were associated with the transformation of potentially toxic aromatic hydrocarbons, which do not support growth of this particular bacterium. Additionally, a deficiency in coenzyme A caused by a highly productive substrate transformation may induce the excretion of a surplus of metabolites in order to regain coenzyme A. Under natural conditions, i.e., in the presence of mixed communities, such transformation products may be further degraded by other organisms, ultimately leading to mineralization.

在许多自然的和人为的叠印环境中都可以观察到主要与石油有关的碳氢化合物的厌氧生物降解。尽管使用微生物和化学示踪剂来研究此类生境的发育，但对特定细菌对系统的影响知之甚少。因此，我们使用了Aromatoleum sp.。HxN1，n能够在严格缺氧条件下降解原油成分的利用链烷烃的β变形杆菌作为模型生物，以检查其将羧酸代谢物释放到周围环境中的潜力。我们进行了纯底物和原油的培养实验，证明代谢代谢途径的中间体在代谢组中高度丰富。令人惊讶的是，在原油培养的HxN1菌株的无细胞培养上清液中发现的最高浓度的代谢物与潜在有毒的芳香烃的转化有关，这不支持该特定细菌的生长。此外，