From Rare to Dominant: a Fine-Tuned Soil Bacterial Bloom during Petroleum Hydrocarbon Bioremediation
From Rare to Dominant: a Fine-Tuned Soil Bacterial Bloom during Petroleum Hydrocarbon Bioremediation
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DOI：
10.1128/aem.02625-15
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发表时间：
2016-02-01
影响因子：
4.4
通讯作者：
Seeger, Michael
中科院分区：
文献类型：
--
作者：
Fuentes, Sebastian;Barra, Barbara;Seeger, Michael
碳氢化合物是分布在世界各地的污染物，会扰乱各种生态系统。本研究的目的是描述土壤微生物群落对碳氢化合物污染和不同生物修复处理的响应的短时动态。复制的柴油添加土壤微宇宙被接种一个确定的细菌联合体或一个氢碳碎裂细菌富集物，并培养12周。利用Illumina 16S rRNA基因测序，每周跟踪微生物群落的动态。细菌群和富集菌都促进了柴油污染土壤中碳氢化合物的降解。在所有柴油污染的土壤中都观察到了一种明显而快速的天然伽马蛋白细菌的繁殖。与碱茅属相关的一个独特的可操作分类单位(OTU)与原始群落中0.1%的序列相似，但令人惊讶的是，6周后达到了60%。尽管有这种与碱解相关的水华，但接种的菌株仍保留在群落中，这可能解释了碳氢化合物降解的差异。这项研究显示了土壤细菌水华对碳氢化合物污染的详细动态，类似于在海洋环境中观察到的微生物水华。在土壤等高度多样性的环境中，稀有的群落成员可能是生态功能的蓄水池。这种从罕见到优势的细菌转变说明了面临剧烈环境干扰的罕见生物圈的潜在作用。此外，它还支持“有条件稀有类群”的概念，即稀有性是一种受环境制约的临时状态。
Hydrocarbons are worldwide-distributed pollutants that disturb various ecosystems. The aim of this study was to characterize the short-lapse dynamics of soil microbial communities in response to hydrocarbon pollution and different bioremediation treatments. Replicate diesel-spiked soil microcosms were inoculated with either a defined bacterial consortium or a hydrocarbonoclastic bacterial enrichment and incubated for 12 weeks. The microbial community dynamics was followed weekly in microcosms using Illumina 16S rRNA gene sequencing. Both the bacterial consortium and enrichment enhanced hydrocarbon degradation in diesel-polluted soils. A pronounced and rapid bloom of a native gammaproteobacterium was observed in all diesel-polluted soils. A unique operational taxonomic unit (OTU) related to the Alkanindiges genus represented similar to 0.1% of the sequences in the original community but surprisingly reached>60% after 6 weeks. Despite this Alkanindiges-related bloom, inoculated strains were maintained in the community and may explain the differences in hydrocarbon degradation. This study shows the detailed dynamics of a soil bacterial bloom in response to hydrocarbon pollution, resembling microbial blooms observed in marine environments. Rare community members presumably act as a reservoir of ecological functions in high-diversity environments, such as soils. This rare-to-dominant bacterial shift illustrates the potential role of a rare biosphere facing drastic environmental disturbances. Additionally, it supports the concept of "conditionally rare taxa," in which rareness is a temporary state conditioned by environmental constraints.