Responses of microbial community from tropical pristine coastal soil to crude oil contamination.
Responses of microbial community from tropical pristine coastal soil to crude oil contamination.
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作者：
Morais D;Pylro V;Clark IM;Hirsch PR;Tótola MR
巴西近海原油勘探增加了，因为在水面下7000米深处发现了新的油藏。这些地区附近的海洋岛屿代表着敏感的环境，在那里，由于石油污染导致的微生物群落变化可能意味着代谢功能的丧失，对这些地点提供的土壤服务产生灾难性影响。本研究旨在评价石油污染对特林达德岛沿海土壤微生物群落（古细菌、细菌和真菌）迁移的影响。将微生物组装并分成两组，对照和污染（浓度为30 g kg - 1的风化原油），一式三份。土壤被培养了38天，每4小时测量一次二氧化碳。孵育后，提取总DNA，纯化并使用Illumina MiSeq平台进行16S rDNA的目标测序，用于细菌和古生菌结构域和真菌ITS1区域。污染后3 d， CO2排放率达到峰值，达到对照的20倍以上，并且在整个孵化期内排放率都保持在较高水平。受污染样品的微生物α多样性降低。受污染样品的真菌相对丰度降低到几乎占观察到的总物种的40%。分类学比较显示放线菌门的增加，几个变形菌纲的转移和古菌纲亚硝基球菌的减少。这是在获取有关原油污染对巴西海洋岛屿土壤影响的知识方面的第一次努力。这一信息对于指导未来可能需要的任何生物修复策略都是重要的。
Brazilian offshore crude oil exploration has increased after the discovery of new reservoirs in the region known as pré-sal, in a depth of 7.000 m under the water surface. Oceanic islands near these areas represent sensitive environments, where changes in microbial communities due oil contamination could stand for the loss of metabolic functions, with catastrophic effects to the soil services provided from these locations. This work aimed to evaluate the effect of petroleum contamination on microbial community shifts (Archaea, Bacteria and Fungi) from Trindade Island coastal soils. Microcosms were assembled and divided in two treatments, control and contaminated (weathered crude oil at the concentration of 30 g kg−1), in triplicate. Soils were incubated for 38 days, with CO2 measurements every four hours. After incubation, the total DNA was extracted, purified and submitted for target sequencing of 16S rDNA, for Bacteria and Archaea domains and Fungal ITS1 region, using the Illumina MiSeq platform. Three days after contamination, the CO2 emission rate peaked at more than 20 × the control and the emissions remained higher during the whole incubation period. Microbial alpha-diversity was reduced for contaminated-samples. Fungal relative abundance of contaminated samples was reduced to almost 40% of the total observed species. Taxonomy comparisons showed rise of the Actinobacteria phylum, shifts in several Proteobacteria classes and reduction of the Archaea class Nitrososphaerales. This is the first effort in acquiring knowledge concerning the effect of crude oil contamination in soils of a Brazilian oceanic island. This information is important to guide any future bioremediation strategy that can be required.