Bigelow Laboratory for Ocean Sciences, 180 McKown Point Road, Post Office Box 475, West Boothbay Harbor, ME 04575, USA.
Science. 2011 Sep 2;333(6047):1296-300. doi: 10.1126/science.1203690.
Recent studies suggest that unidentified prokaryotes fix inorganic carbon at globally significant rates in the immense dark ocean. Using single-cell sorting and whole-genome amplification of prokaryotes from two subtropical gyres, we obtained genomic DNA from 738 cells representing most cosmopolitan lineages. Multiple cells of Deltaproteobacteria cluster SAR324, Gammaproteobacteria clusters ARCTIC96BD-19 and Agg47, and some Oceanospirillales from the lower mesopelagic contained ribulose-1,5-bisphosphate carboxylase-oxygenase and sulfur oxidation genes. These results corroborated community DNA and RNA profiling from diverse geographic regions. The SAR324 genomes also suggested C(1) metabolism and a particle-associated life-style. Microautoradiography and fluorescence in situ hybridization confirmed bicarbonate uptake and particle association of SAR324 cells. Our study suggests potential chemolithoautotrophy in several uncultured Proteobacteria lineages that are ubiquitous in the dark oxygenated ocean and provides new perspective on carbon cycling in the ocean's largest habitat.
最近的研究表明，在广阔的黑暗海洋中，无法识别的原核生物以全球重要的速度固定无机碳。通过对两个亚热带旋流中微生物的单细胞分选和全基因组扩增，我们从代表大多数世界性谱系的 738 个细胞中获得了基因组 DNA。来自德尔塔变形菌群 SAR324、γ变形菌群 ARCTIC96BD-19 和 Agg47 以及一些下中层海洋螺旋体的多个细胞含有核酮糖-1,5-二磷酸羧化酶-加氧酶和硫氧化基因。这些结果与来自不同地理区域的群落 DNA 和 RNA 分析相吻合。SAR324 基因组还表明 C(1)代谢和与颗粒相关的生活方式。微量放射性自显影和荧光原位杂交证实了 SAR324 细胞对碳酸氢盐的摄取和对颗粒的附着。我们的研究表明，在黑暗含氧海洋中普遍存在的几个未培养的变形菌谱系中存在潜在的化能自养能力，并为海洋最大栖息地的碳循环提供了新的视角。
