Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001. Col. Chamilpa., Cuernavaca, Morelos, 62210, México.
Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001. Col. Chamilpa., Cuernavaca, Morelos, 62210, México.
World J Microbiol Biotechnol. 2023 Jul 29;39(10):264. doi: 10.1007/s11274-023-03703-3.
Bacterial degradation of crude oil is a promising strategy for reducing the concentration of hydrocarbons in contaminated environments. In the first part of this study, we report the enrichment of two bacterial consortia from deep sediments of the Gulf of Mexico with crude oil as the sole carbon and energy source. We conducted a comparative analysis of the bacterial community in the original sediment, assessing its diversity, and compared it to the enrichment observed after exposure to crude oil in defined cultures. The consortium exhibiting the highest hydrocarbon degradation was predominantly enriched with Rhodococcus (75%). Bacterial community analysis revealed the presence of other hydrocarbonoclastic members in both consortia. In the second part, we report the isolation of the strain Rhodococcus sp. GOMB7 with crude oil as a unique carbon source under microaerobic conditions and its characterization. This strain demonstrated the ability to degrade long-chain alkanes, including eicosane, tetracosane, and octacosane. We named this new strain Rhodococcus qingshengii GOMB7. Genome analysis revealed the presence of several genes related to aromatic compound degradation, such as benA, benB, benC, catA, catB, and catC; and five alkB genes related to alkane degradation. Although members of the genus Rhodococcus are well known for their great metabolic versatility, including the aerobic degradation of recalcitrant organic compounds such as petroleum hydrocarbons, this is the first report of a novel strain of Rhodococcus capable of degrading long-chain alkanes under microaerobic conditions. The potential of R. qingshengii GOMB7 for applications in bioreactors or controlled systems with low oxygen levels offers an energy-efficient approach for treating crude oil-contaminated water and sediments.
细菌降解原油是降低污染环境中碳氢化合物浓度的一种很有前途的策略。在本研究的第一部分，我们报告了从墨西哥湾深海沉积物中富集的两个细菌共生体，以原油作为唯一的碳源和能源。我们对原始沉积物中的细菌群落进行了多样性分析，并将其与暴露于原油后的富集情况进行了比较。表现出最高烃类降解能力的共生体主要富集了 Rhodococcus（75%）。细菌群落分析显示，两个共生体中都存在其他烃类降解成员。在第二部分，我们报告了在微氧条件下以原油为唯一碳源从共生体中分离出一株 Rhodococcus sp. GOMB7 并对其进行了表征。该菌株表现出降解长链烷烃的能力，包括二十烷、二十四烷和二十八烷。我们将这个新菌株命名为 Rhodococcus qingshengii GOMB7。基因组分析显示存在与芳香族化合物降解相关的几个基因，如 benA、benB、benC、catA、catB 和 catC；以及五个与烷烃降解相关的 alkB 基因。尽管 Rhodococcus 属的成员以其强大的代谢多功能性而闻名，包括对难降解有机化合物（如石油烃）的好氧降解，但这是第一个报道的能够在微氧条件下降解长链烷烃的新型 Rhodococcus 菌株。R. qingshengii GOMB7 在低氧水平的生物反应器或控制系统中的应用潜力为处理受原油污染的水和沉积物提供了一种节能的方法。
