Year-round Microbiome Composition Change of Azooxanthellate Coral and Seawater in the South Sea

Abstract

The warm current running from tropical Philippines through subtropical Taiwan to the temperate region Korea, the Kuroshio transfers heat from lower to higher latitudes. It warmed most rapidly in 1981–1998, when sea surface temperatures rose by 1.5°C (0.9°C/decade), almost 7 times the global rate. This affected the physiological responses of corals as well as the corals habitat range. We chose Eleutherobia rubra, a azooxanthellate soft coral around Korea to investigate the microbiome composition and to compare with the habitat seawater microbiome change along the year. This study focused on the identification of the microbiome from E. rubra and seawater from its habitat and its diversity and the microbiome composition change in four seasons. As results, Proteobacteria was mainly found with 53.5% and secondly Bacteroidetes with 9.9% from all coral samples and Proteobacteria with 47.6% and Bacteroidetes with 25.6% from seawater. The family, Endozoicomonadaceae with 26% and Spirochaetaceae with 8.5% were found from the coral samples along the four seasons and the family, Flavobacteriaceae with 16.4% and Pseudomonadaceae with 10.8% from seawater. Endozoicomonas elysicola was the species showing the highest count rate from the coral samples and Psuedomonas gramnis was the species showing the highest count rate from the seawater samples and any endozoicomonas species were found in the seawater samples.