Keywords:
Compound specific stable nitrogen isotope analysis of amino acids
and sulfur-containing component analysis of reef corals: Toward
method development for the prevention of coral bleaching and for
recovering from damaged status.
*Yohei Matsui1,2, Toshihiro Miyajima1, Tomihiko Higuchi1, Kentaro Tanaka1, Naoko Morimoto1,
Yanhui Yang1, Hiroyuki Fujimura3, Naoko Yasuda3, Sylvain Agostini4, Ikuko Yuyama4, Takashi
Nakamura5, Masahiro Yuki6, Shingo Kato6, Wataru Fujisaki2
1. Atmosphere and Ocean Research Institute (AORI), The University of Tokyo, 2. Japan Agency for Marine-Earth
Science and Techonology (JAMSTEC), 3. University of the Ryukyus, 4. University of Tsukuba, 5. Tokyo Institute of
Technology, 6. RIKEN 
To save reef corals from bleaching event, we investigated possibility of enhancement of tolerance and
resilience of corals against temperature stress by controlled feeding. By analyzing bulk stable carbon and
nitrogen isotope ratios, as well as compound specific isotope analysis of amino acids of coral animal host
and symbiotic algae under natural condition, we aim for enhancing our understanding of the major
nutrition source and pathway, and for proposing coral bleaching vulnerability indicators for coral reef
ecology. Sulfur containing protein and sulfate minerals were also analyzed by GC-MS and X-ray
diffractometer. Although compound specific isotope analysis of amino acids is an established analytical
method, accomplishing good derivatization of carboxyl and amine functional groups without generating
incomplete derivatization or fragmental/recoupled impure molecules gain experience. Analytical machine
side, internal/external leak, oxidation/reduction capability of reactors, surface area of catalyst, and
degree of gas flow easiness inside of the reactor tubings are considered essential for stable and precise
analytical campaign. Coral species used for this experiment (Acropora hyacinthus and Acropora cf. glauca
) contain large number of cnidocytes, such as spirocysts and type b-mastigophores. To isolate symbionts
from nematocysts, we applied flow cytometry technique with cell sorting function. Parameters, such as
side scatter, forward scatter, green fluorescent, and chlorophyll autofluorescent induced by 488-nm blue
laser emission were used for the isolation. By establishing those isolation and precise isotope analysis
technique, we have developed evaluation roadmap to confirm an effect of nutrition control for the reef
corals. 
Coral bleaching, Stable nitrogen isotope ratio of amino acids, Sulfur 
ACG56-P02JpGU-AGU Joint Meeting 2020
©2020. Japan Geoscience Union. All Right Reserved.- ACG56-P02 -