Abstract Oil and fuel spills occur regularly in terrestrial and aquatic environments and substances such as crude oil can contain many compounds that are highly resistant to degradation. Among these constituents are alkanes and monoaromatic and polycyclic aromatic hydrocarbons (PAHs), which are not only toxic but also carcinogenic and/or mutagenic. Provided there are sufficient nutrient levels and proper growth conditions, many complex hydrocarbons, including PAHs, readily biodegrade under aerobic conditions (i.e., in the presence of oxygen). However, oxygen-depleted environments are ubiquitous, e.g., deep subsurfaces or general aerobic environments where biological oxygen consumption exceeds replenishment. Anaerobic bacteria and archaea in such anaerobic environments are the dominant catalysts to initiate and complete degradation, including most PAHs. It is therefore imperative to understand the biochemical reactions and mechanisms by which anaerobic degradation takes place though much slower compared with those under aerobic conditions. For alkanes and aromatics, new biochemical mechanisms carried out by the genes and enzymes responsible have been reported to advance and enrich the knowledge on anaerobic transformation. However, validation of these biochemical reactions have not been fully rectified with convincing results of the expression of the genes and also the chemical signature degradation intermediates in oil production system or oil contaminated sites. In order to better mitigate the contaminated sites, biostimulation and bioaugmentation are discussed for accelerated and effective removal of petroleum oil or specific constituents.

中文翻译：

---

努力理解和改进石油烃的厌氧生物降解：文献综述

摘要 石油和燃料泄漏经常发生在陆地和水生环境中，原油等物质可能含有许多高度抗降解的化合物。这些成分包括烷烃和单芳烃和多环芳烃 (PAH)，它们不仅有毒，而且具有致癌性和/或致突变性。只要有足够的营养水平和适当的生长条件，许多复杂的碳氢化合物，包括多环芳烃，在有氧条件下（即在有氧的情况下）很容易生物降解。然而，缺氧环境无处不在，例如，生物耗氧量超过补充量的深层地下或一般有氧环境。在这种厌氧环境中，厌氧细菌和古细菌是引发和完全降解的主要催化剂，包括大多数 PAH。因此，必须了解厌氧降解发生的生化反应和机制，尽管与有氧条件下的降解相比要慢得多。对于烷烃和芳烃，据报道，由负责的基因和酶执行的新生化机制可以推进和丰富有关厌氧转化的知识。然而，这些生化反应的验证尚未得到令人信服的基因表达结果以及石油生产系统或石油污染场地中化学特征降解中间体的完全纠正。为了更好地减轻污染场地，讨论了生物刺激和生物强化以加速和有效去除石油或特定成分。因此，必须了解厌氧降解发生的生化反应和机制，尽管与有氧条件下的降解相比要慢得多。对于烷烃和芳烃，据报道，由负责的基因和酶执行的新生化机制可以推进和丰富有关厌氧转化的知识。然而，这些生化反应的验证尚未得到令人信服的基因表达结果以及石油生产系统或石油污染场地中化学特征降解中间体的完全纠正。为了更好地减轻污染场地，讨论了生物刺激和生物强化以加速和有效去除石油或特定成分。因此，必须了解厌氧降解发生的生化反应和机制，尽管与有氧条件下的降解相比要慢得多。对于烷烃和芳烃，据报道，由负责的基因和酶执行的新生化机制可以推进和丰富有关厌氧转化的知识。然而，这些生化反应的验证尚未得到令人信服的基因表达结果以及石油生产系统或石油污染场地中化学特征降解中间体的完全纠正。为了更好地减轻污染场地，讨论了生物刺激和生物强化以加速和有效去除石油或特定成分。