Department of Biomolecular Sciences, University of Urbino Carlo Bo, Urbino (PU), Italy.
R&D Engineering, Asset Based Services-Saipem SpA, Fano (PU), Italy.
PLoS One. 2024 Sep 4;19(9):e0309971. doi: 10.1371/journal.pone.0309971. eCollection 2024.
Microbiologically Influenced Corrosion (MIC) is one of the main threats for marine infrastructures, leading to severe safety and environmental risks associated with structural failures and/or leakages of dangerous fluids, together with potential huge economic losses and reputational damage for the involved parts. For a safe design and a proper installation of infrastructure systems in contact with the seabed, a deep knowledge of the site-specific microbial community of the sediments should be beneficial. Therefore, in addition to the simple detection or the sole quantification of Sulphate-Reducing Bacteria (SRB), the whole characterization of the microbial members involved in MIC phenomena is desirable. In this study, 16S rRNA-based comparison between bacterial communities thriving in offshore and nearshore marine sediments was performed, with a focus on the main bacterial groups putatively responsible for MIC. The nearshore sediments were significantly enriched in bacterial members associated with human and organic compounds contamination belonging to the Bacteroidota, Desulfobacterota, and Firmicutes phyla, while the offshore sediments hosted Alphaproteobacteria, Nitrospinota, and Nitrospirota members, representative of a low anthropogenic impact. Quantitative PCR targeting the dsrA gene and detailed community analyses revealed that the nearshore sediments were significantly enriched in SRB mainly affiliated to the Desulfobulbus and Desulfosarcina genera potentially involved in biocorrosion, compared to the offshore ones. These results suggest that the bacterial community associated with the high concentration of organic compounds derived by an elevated anthropogenic impact is likely to favour MIC. Such observations highlight the importance of microbiological investigations as prevention strategy against MIC processes, aiming both at characterizing sites for the establishment of new infrastructures and at monitoring those already installed.
微生物影响腐蚀（MIC）是海洋基础设施的主要威胁之一，会导致与结构失效和/或危险流体泄漏相关的严重安全和环境风险，同时还会给相关各方带来潜在的巨大经济损失和声誉损害。为了安全设计和正确安装与海底接触的基础设施系统，深入了解沉积物中特定于地点的微生物群落应该是有益的。因此，除了简单地检测或仅仅定量硫酸盐还原菌（SRB）外，还需要对参与 MIC 现象的微生物成员进行全面表征。在这项研究中，对近海和近岸海洋沉积物中繁荣的细菌群落进行了基于 16S rRNA 的比较，重点是与 MIC 现象有关的主要细菌群。近岸沉积物中富含与人类和有机化合物污染有关的细菌成员，属于拟杆菌门、脱硫杆菌门和厚壁菌门，而近海沉积物则含有α变形菌门、硝化螺菌门和硝化螺旋菌门成员，代表着低人为影响。针对 dsrA 基因的定量 PCR 和详细的群落分析表明，与近海沉积物相比，近岸沉积物中富含主要与脱硫弧菌和脱硫弧菌属相关的 SRB，这些菌属可能参与生物腐蚀。这些结果表明，与高浓度有机化合物相关的细菌群落可能有利于 MIC，而高浓度有机化合物则来自于人为活动的增加。这些观察结果强调了微生物学调查作为预防 MIC 过程的策略的重要性，旨在对新基础设施的建立和已安装的基础设施进行特征描述和监测。
