Research Progress on Amino Acid Indication of Degradation Behavior of Organic Matter in Ocean

Abstract

Amino acid is an important biogenic organic matter in the ocean, which plays a very important role in the biogeochemical cycle of organic carbon and organic nitrogen.  Amino acids, as active components in marine organisms, are selectively removed by heterotrophic bacteria in the process of organic matter degradation, and are sensitive indicators to indicate the degree of organic matter degradation in the ocean. This paper first introduces the classification of amino acids in seawater, and summarizes the sources and biological activities of dissolved free amino acids (DFAA ), dissolved binding amino acids (DCAA ), granular amino acids (PAA ), and bacterial markers (D- amino acids ).

At the same time, the change of amino acids in the process of organic matter degradation can be attributed to selective preservation, three mechanisms of producing or enriching bacterial source substances and bacterial transformation. Finally, this paper summarizes the 6 degradation factors based on amino acids: the contribution rate of dissolved amino acids (THAA ) to organic carbon or organic nitrogen (THAA-C% or THAA-N% ), degradation factors (degradation index), activity factors (reactivity index ), and individual amino acids D/ L ratio, aspartic acid / beta - alanine or glutamic acid / gamma - amino butyric acid ratio (ASP/beta,-ala or Glu/gamma,-ABA ) and contribution rate of bacteria-derived organic matter, their respective characteristics, applicable degradation stage and specific application.