Polymenakou Paraskevi N, Christakis Christos A, Mandalakis Manolis, Oulas Anastasis
Hellenic Centre for Marine Research (IMBBC-HCMR), Institute of Marine Biology, Biotechnology and Aquaculture, Gournes Pediados, 71500 Heraklion Crete, Greece.
Hellenic Centre for Marine Research (IMBBC-HCMR), Institute of Marine Biology, Biotechnology and Aquaculture, Gournes Pediados, 71500 Heraklion Crete, Greece.
Res Microbiol. 2015 Jun;166(5):448-457. doi: 10.1016/j.resmic.2015.03.005. Epub 2015 Apr 20.
The deep eastern basin of the Mediterranean Sea is considered to be one of the world's most oligotrophic areas in the world. Here we performed pyrosequenicng analysis of bacterial and archaeal communities in oxic nutrient-poor sediments collected from the eastern Mediterranean at 1025-4393 m depth. Microbial communities were surveyed by targeting the hypervariable V5-V6 regions of the 16S ribosomal RNA gene using bar-coded pyrosequencing. With a total of 13,194 operational taxonomic units (OTUs) or phylotypes at 97% sequence similarities, the phylogenetic affiliation of microbes was assigned to 23 bacterial and 2 archaeal known phyla, 23 candidate divisions at the phylum level and distributed into 186 families. It was further revealed that the microbial consortia inhabiting all sampling sites were highly diverse, but dominated by phylotypes closely related to members of the genus Pseudomonas and Marine Group I archaea. Such pronounced and widespread enrichment probably manifests the cosmopolitan character of these species and raises questions about their metabolic adaptation to the physical stressors and low nutrient availability of the deep eastern Mediterranean Sea.
地中海东部深海盆地被认为是世界上最贫营养的地区之一。在此，我们对从地中海东部1025 - 4393米深处采集的贫氧营养沉积物中的细菌和古菌群落进行了焦磷酸测序分析。通过使用条形码焦磷酸测序靶向16S核糖体RNA基因的高变V5 - V6区域来调查微生物群落。在97%序列相似性水平上共有13194个操作分类单元（OTU）或系统发育型，微生物的系统发育归属被确定为23个已知细菌门和2个古菌门、23个门水平的候选类群，并分布在186个科中。进一步揭示出，栖息在所有采样点的微生物聚生体具有高度多样性，但以与假单胞菌属成员和海洋第一类群古菌密切相关的系统发育型为主。这种显著且广泛的富集可能体现了这些物种的世界性特征，并引发了关于它们如何代谢适应地中海东部深海的物理压力源和低营养可利用性的问题。
