热带东太平洋中国多金属结核开辟区深海成矿环境的氨基酸表征

Amino Acids as An Indicator of Deep Sea Mineralization Environment in the China Pioneer Area,Tropical East Pacific Ocean

为了解中国多金属结核开辟区沉积物有机质活性及深海成矿沉积环境特征,使用高效液相色谱(HPLC)法分析了表层沉积物氨基酸的组成状况。结果显示该区表层沉积物中氨基酸与氨基糖含量(干样)均较低,分别在0.30～0.59mg.g-1及0.10～0.17mg.g-1之间。其中以中性氨基酸占绝对优势,占50%以上,其次为酸性氨基酸和含氢氧基氨基酸,分别占17%和11%,碱性氨基酸占9%,芳香与含硫氨基酸均在5%以下,表明深海沉积环境为氧化环境,且偏碱性条件。表征有机质活性的Asp/β-Ala、Glu/γ-Aba及DI值((Glu+Phe+Leu+Ala+Val)/(β-Ala+γ-Aba))分别为1.1～1.9,0.8～2.2和1.4～2.9,表明该区有机质成熟度已很高。蛋白氨基酸/非蛋白氨基酸的比值为1.0～2.0,葡萄糖胺/半乳糖胺比值则在1.7～3.0之间变化,表明该海区有机质经过强烈的细菌改造,即海区存在强烈的细菌活动,活性较低,表征了多金属结核有机—微生物成矿的可能性。

In order to investigate the organic matter liability and sedimentary environments in the China Pioneer area, Tropical East Pacific Ocean, sediment hydrolysable amino acids were analyzed using HPLC. The contents of amino acids and amino sugars were low in the study area, 0.3 -0.5 mg·g^-1 and 0. 10 -0.17 mg · g^-1 （dry weight） , respectively. The division of functional groups of protein amino acids showed that the neutral amino acids dominated （ 〉50 mol% ） , and the acidic, hydroxylic, basic, aromatic and sulfuric amino acids account for 17, 11,9, 〈5 and 〈5 mol% respectively. The result indicates that the characteristics of the deep ocean sedimentary environment was slightly alkaline and oxidative. The degradation index （DI） and the ratio of Asp/β-Ala,Glu/γ-Aba showed high decomposition state of the organic matter in the study area. And the ratio of non-protein/protein amino acids and Glum/ Gal showed that the organic matter were strongly reconstructed by microbe, indicates the possibility of the organic-microbial mineralization of the oceanic polymetallic nodules in the study area.