Hydrogen is an energy source for hydrothermal vent symbioses

The discovery of deep-sea hydrothermal vents in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. Hydrothermal vent ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ hybridization, immunohistochemistry, shipboard incubations and in situ mass spectrometry, we show here that the symbionts of the hydrothermal vent mussel Bathymodiolus from the Mid-Atlantic Ridge use hydrogen to power primary production. In addition, we show that the symbionts of Bathymodiolus mussels from Pacific vents have hupL, the key gene for hydrogen oxidation. Furthermore, the symbionts of other vent animals such as the tubeworm Riftia pachyptila and the shrimp Rimicaris exoculata also have hupL. We propose that the ability to use hydrogen as an energy source is widespread in hydrothermal vent symbioses, particularly at sites where hydrogen is abundant.     

西藏甲玛铜多金属矿含矿斑岩石英斑晶单个熔融包裹体的成分研究

研究甲玛铜多金属矿床岩浆结晶演化特点、岩浆热液过渡与矿化的关系。利用Linkam TS1500热台对甲玛矿床含矿斑岩石英斑晶中的熔融包裹体进行鉴定、均一温度测定,采用电子探针与同步辐射X射线荧光微探针对石英斑晶中的熔融包裹体进行常量元素及微量元素的测定,结果表明,含矿斑岩体形成温度为630~880℃。Na、Ca等元素易富集于岩浆挥发组分中,挥发组分饱和出溶形成高温、高盐度流体,成矿元素从最早的岩浆结晶分异阶段开始,强烈地选择性进入挥发性气相中进行迁移,出溶的挥发组分中具有成矿元素的初步富集。矿床在成因上与斑岩-夕卡岩成矿系统中的岩浆-热液成矿作用密切相关。