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

Key words: 
• amino acids /
• deep ocean mineralization environment /
• organic matter decomposition /
• Tropical East Pacific Ocean /

Abstract: 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.