Amino acids in water samples from deep sea hydrothermal vents at Suiyo Seamount, Izu-Bonin Arc, Pacific Ocean

Pure seawater samples, at a temperature of 300 °C (purity >97%) were collected from deep-sea hydrothermal vents at Suiyo Seamount, Izu-Bonin Arc, Pacific Ocean as a part of the Archaean Park Project. Dissolved and total hydrolyzable amino acids were determined by ion-exchange HPLC, and for the first time, their enantiomeric ratios were measured by reversed-phase HPLC. Glycine and serine were the two most abundant amino acids, followed by other proteinaceous amino acids such as alanine, glutamic acid and aspartic acid. Non-proteinaceous amino acids, e.g. β-alanine and γ-aminobutyric acid, were as minor constituents. The majority of the amino acids detected were of the -form which suggests most of the amino acids detected were formed biologically and that there are active microbial communities near these hydrothermal systems.