In order to evaluate the corrosive action of microorganisms on 316L metal exposed directly to a marine environment, a system was designed to immerse coupons in seawater. After periods of 30, 60 and 90 days, the coupons were recovered, the corrosion rates evaluated and the biofilm samples on their surface were analyzed by 16S rRNA gene sequencing. The results of the corrosion rate showed an acceleration over the entire experimental period. Alpha diversity measurements showed higher rates after 60 days of the experiment, while abundance measurements showed higher rates after 90 days of exposure to the marine environment. The beta-diversity results showed a clear separation between the three conditions and proximity in the indices between replicates of the same experimental condition. The results of 16S rRNA gene sequencing showed that after 30 days of exposure to seawater, there was massive representativeness of the pioneer bacteria, Gamma and Alphaproteobacteria , with emphasis on the genera Alcanivorax , Oceanospirillum and Shewanella . At the 60-day analysis, the Gammaproteobacteria class remained dominant, followed by Alphaproteobacteria and Flavobacteria , and the main representatives were Flexibacter and Pseudoalteromonas . In the last analysis, after 90 days, a change in the described bacterial community profile was observed. The Gammaproteobacteria class was still the largest in diversity and OTUs. The most predominant genera in number of OTUs were Alteromonas , Bacteriovorax and, Nautella . Our results describe a change in the microbial community over coupons directly exposed to the marine environment, suggesting a redirection to the formation of a mature biofilm. The conditions created by the biofilm structure suggest said condition favor biocorrosion on the analyzed coupons.

中文翻译：

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通过 Illumina MiSeq 测序对 316L 不锈钢试样进行海洋细菌群落分析

为了评估微生物对直接暴露在海洋环境中的 316L 金属的腐蚀作用，设计了一个将试样浸入海水中的系统。30、60 和 90 天后，回收试样，评估腐蚀速率，并通过 16S rRNA 基因测序分析其表面的生物膜样品。腐蚀速率的结果显示在整个实验期间加速。Alpha 多样性测量在实验 60 天后显示出更高的比率，而在暴露于海洋环境 90 天后，丰度测量显示出更高的比率。β 多样性结果显示三种条件之间存在明显的分离，并且相同实验条件的重复之间的指数接近。16S rRNA基因测序结果表明，暴露于海水30天后，先锋菌Gamma和Alphaproteobacteria具有大量代表性，重点是Alcanivorax、Oceanospirillum和Shewanella属。在60天的分析中，Gammaproteobacteria类仍然占优势，其次是Alphaproteobacteria和Flavobacteria，主要代表是Flexibacter和Pseudoalteromonas。在最后一次分析中，90 天后，观察到所描述的细菌群落概况发生了变化。Gammaproteobacteria 类在多样性和 OTU 方面仍然是最大的。OTU 数量最多的属是交替单胞菌属、食菌属和鹦鹉螺属。我们的结果描述了直接暴露于海洋环境的试样上微生物群落的变化，表明重新定向到成熟生物膜的形成。由生物膜结构产生的条件表明，所述条件有利于分析试样上的生物腐蚀。