Departamento de Recursos del Mar, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mérida, Yucatán, Mexico.
Consorcio de Investigación del Golfo de México (CIGOM), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mérida, Yucatán, Mexico.
Microb Ecol. 2021 May;81(4):908-921. doi: 10.1007/s00248-020-01631-5. Epub 2020 Nov 9.
This study investigates the community composition, structure, and abundance of sulfate-reducing microorganisms (SRM) in surficial sediments of the Northwestern Gulf of Mexico (NWGoM) along a bathymetric gradient. For these purposes, Illumina sequencing and quantitative PCR (qPCR) of the dissimilatory sulfite reductase gene beta subunit (dsrB gene) were performed. Bioinformatic analyses indicated that SRM community was predominantly composed by members of Proteobacteria and Firmicutes across all the samples. However, Actinobacteria, Thermodesulfobacteria, and Chlorobi were also detected. Phylogenetic analysis indicated that unassigned dsrB sequences were related to Deltaproteobacteria and Nitrospirota superclusters, Euryarchaeota, and to environmental clusters. PCoA ordination revealed that samples clustered in three different groups. PERMANOVA indicated that water depth, temperature, redox, and nickel and cadmium content were the main environmental drivers for the SRM communities in the studied sites. Alpha diversity and abundance of SRM were lower for deeper sites, suggesting decreasing sulfate reduction activity with respect to water depth. This study contributes with the understanding of distribution and composition of dsrAB-containing microorganisms involved in sulfur transformations that may contribute to the resilience and stability of the benthic microbial communities facing metal and hydrocarbon pollution in the NWGoM, a region of recent development for oil and gas drilling.
本研究调查了墨西哥湾西北部（NWGoM）沿水深梯度的表层沉积物中硫酸盐还原微生物（SRM）的群落组成、结构和丰度。为此，进行了 Illumina 测序和异化亚硫酸盐还原酶基因β亚基（dsrB 基因）的定量 PCR（qPCR）。生物信息学分析表明，SRM 群落主要由所有样品中的变形菌门和厚壁菌门组成。然而，也检测到放线菌门、热脱硫杆菌门和绿菌门。系统发育分析表明，未分类的 dsrB 序列与 δ 变形菌门和硝化螺旋菌超群、古菌以及环境群有关。PCoA 排序表明，样品聚类为三个不同的组。PERMANOVA 表明，水深、温度、氧化还原电位以及镍和镉含量是研究地点 SRM 群落的主要环境驱动因素。深度较大的地点的 SRM 多样性和丰度较低，表明硫酸盐还原活性随水深降低。本研究有助于了解参与硫转化的 dsrAB 含微生物的分布和组成，这可能有助于面对金属和碳氢化合物污染的 NWGoM 底栖微生物群落的恢复力和稳定性，该地区最近开发了石油和天然气钻探。
