The objectives of this study were to analyze the difference in ways in which metals polluting Brazilian port areas influence bacterial communities and the selection of resistant strains. The hypothesis tested was that port areas would have microbial communities significantly different from a pristine area, mainly due to a greater load of metals found in these areas. Sediment samples were collected in two port areas (Santos and São Sebastião) and one pristine area (Ubatuba). Total DNA was extracted and MiSeq sequencing was performed. A hundred strains were isolated from the same samples and were tested for metal resistance. The community composition was similar in the two port regions, but differed from the pristine area. Microbial diversity was significantly lower in the port areas. The phyla Proteobacteria, Cyanobacteria, and Thermodesulfobacteria exhibited positive correlations with copper and zinc concentrations. Chloroflex, Nitrospirae, Planctomycetes, and Chlorobi exhibited negative correlations with copper, chromium, and zinc. Cr and Zn had higher concentrations at port areas and were responsible to select more metal-resistant strains. Some genera were found to be able to easily develop metal resistance. The most isolated genera were Bacillus, Vibrio, and Pseudomonas. This type of study can illustrate, even in very complex natural environments, the influence of pollution on the community as a whole and the consequences of these changes.

中文翻译：

---

巴西港口地区的重金属含量及其与微生物的关系：这些地区的污染会改变微生物群落吗？

这项研究的目的是分析污染巴西港口地区的金属影响细菌群落和选择抗性菌株的方式的差异。检验的假设是，港口地区的微生物群落与原始地区明显不同，这主要是由于这些地区发现的金属量更大。在两个港口区域（桑托斯和圣塞瓦斯蒂安）和一个原始区域（乌巴图巴）收集了沉积物样本。提取总DNA，并进行MiSeq测序。从相同样品中分离出一百个菌株，并测试其金属抗性。两个港口区域的社区组成相似，但与原始区域不同。港口地区的微生物多样性明显较低。门菌，蓝细菌和热脱硫细菌与铜和锌的浓度呈正相关。Chloroflex，Nitrospirae，Planctomycetes和Chlorobi与铜，铬和锌呈负相关。铬和锌在港口区域的浓度较高，并负责选择更多的抗金属菌株。发现某些属能够容易地产生金属抗性。最孤立的属是芽孢杆菌，弧菌和假单胞菌。即使在非常复杂的自然环境中，此类研究也可以说明污染对整个社区的影响以及这些变化的后果。