Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America.
Department of Biochemistry, Molecular Biology and Biophysics & Biotechnology Institute, University of Minnesota, St. Paul, Minnesota, United States of America.
PLoS One. 2019 May 16;14(5):e0217059. doi: 10.1371/journal.pone.0217059. eCollection 2019.
Microbial colonization can be detrimental to the integrity of metal surfaces and lead to microbiologically influenced corrosion (MIC). Biocorrosion is a serious problem for aquatic and marine industries in the world. In Minnesota (USA), where this study was conducted, biocorrosion severely affects the maritime transportation industry. The anticorrosion activity of a variety of compounds, including chemical (magnesium peroxide) and biological (surfactin, capsaicin, and gramicidin) molecules were investigated as coating additives. We also evaluated a previously engineered, extremely stable, non-biocidal enzyme known to interfere in bacterial signaling, SsoPox (a quorum quenching lactonase). Experimental steel coupons were submerged in water from the Duluth Superior Harbor (DSH) for 8 weeks in the laboratory. Biocorrosion was evaluated by counting the number and the coverage of corrosion tubercles on coupons and also by ESEM imaging of the coupon surface. Three experimental coating additives significantly reduced the formation of corrosion tubercles: surfactin, magnesium peroxide and the quorum quenching lactonase by 31%, 36% and 50%, respectively. DNA sequence analysis of the V4 region of the bacterial 16S rRNA gene revealed that these decreases in corrosion were associated with significant changes in the composition of bacterial communities on the steel surfaces. These results demonstrate the potential of highly stable quorum quenching lactonases to provide a reliable, cost-effective method to treat steel structures and prevent biocorrosion.
微生物定殖会对金属表面的完整性造成损害，并导致微生物影响的腐蚀（MIC）。生物腐蚀是世界上水生和海洋工业的一个严重问题。在本研究进行的美国明尼苏达州，生物腐蚀严重影响了海洋运输业。各种化合物的防腐活性，包括化学（过氧化镁）和生物（表面活性剂、辣椒素和短杆菌肽）分子，被作为涂层添加剂进行了研究。我们还评估了一种先前设计的、极其稳定的、非杀菌的酶，已知该酶会干扰细菌信号，即 SsoPox（群体感应淬灭内酯酶）。实验用钢试片在实验室中于 Duluth Superior 港（DSH）的水中浸泡 8 周。通过计数试片上腐蚀结节的数量和覆盖度，以及通过试片表面的 ESEM 成像来评估生物腐蚀。三种实验性涂层添加剂显著减少了腐蚀结节的形成：表面活性剂、过氧化镁和群体感应淬灭内酯酶分别减少了 31%、36%和 50%。细菌 16S rRNA 基因 V4 区的 DNA 序列分析表明，这些腐蚀减少与钢表面细菌群落组成的显著变化有关。这些结果表明，高度稳定的群体感应淬灭内酯酶具有提供可靠、具有成本效益的方法来处理钢结构和防止生物腐蚀的潜力。
