海洋中石油烃类降解与微生物腐蚀关系研究

Relationship between Hydrocarbon Degradation and Biocorrosionin Marine Environment

在工程实践中,国家重要的海洋工程设施(如海底输油管线和船舶燃料系统等)发生的腐蚀破坏案例常常涉及到油水环境,并与微生物腐蚀作用密切相关,而了解海洋含油环境中石油烃类的生物转换机制是了解微生物腐蚀的关键。阐述了海洋环境中降解石油烃类的主要微生物及其降解机制,其在有氧和无氧条件下呈现不同的特点。微生物降解石油烃类过程中非常重要的一步即为接受电子,该过程将生物无法直接利用的化学能转换成可直接利用的能量形式,即腺苷三磷酸(ATP)。有氧条件下的烃类降解以氧气作为最终电子受体,而在缺氧条件下可利用硝酸盐、铁离子、硫酸盐等作为电子受体。海洋环境中的石油烃类会促进腐蚀性硫化物的生成,因此油水环境下的微生物腐蚀机理以硫化物的腐蚀破坏为主。此外,烃类降解过程产生的琥珀酸等酸性中间代谢物也会加剧腐蚀的发生。但目前关于海洋油水环境中微生物群落作为一个整体展现出的功能性及其对钢铁设施的破坏机理,仍然缺乏系统性的研究,而基于高通量测序的微生物组学研究技术将成为有效解决这些问题的手段之一。

In engineering practice,the corrosion of some national significant marine infrastructures such as the pipelines of offshore oil-gas exploration and the fueling systems of ships usually occur under the oil-containing conditions and is closely related to serious microbiologically influenced corrosion (MIC).The knowledge about the biodegradation mechanisms of hydrocarbon in marine environment is the essential to understand the MIC mechanisms.The work reviewed the microbial degradation mechanisms and corresponding microbes in oil-containing marine environment,as well as different features under aerobic and anaerobic conditions.The electron-accepting process was a key step in microbial degradation.The energy stored in the hydrocarbon was transferred into adenosine triphosphate (ATP) that was easier to be utilized by microbes in the form of chemical bond.Oxygen acted as electron acceptors under aerobic conditions while nitrate,ferric ion,sulfate and carbon dioxide accepted electrons under anoxic conditions.The degradation of hydrocarbon stimulated the formation of sulfide,so MIC was dominant in oil-containing environment.In addition,the intermediate metabolites during degradation of hydrocarbonsuch as the fatty acids also caused MIC.However,the systematical studies on the functions of microbial communities as a whole and the corrosion mechanisms of steel infrastructuresin marine environment are still scarce.The microbial molecular techniques based on high-throughput sequencing are expected to become one of effective methods to solve these problems.