Comparative Analysis of Bacterial Communities and Diversity in Seaweeds by Exposure Duration to Seashore in Jeju Island

Abstract

Seaweeds have become a global industrial source material in food and cosmetic area. In recent reports, seaweed-associated bacteria play a vital role in nutrient shifts with secondary metabolites in direct and/or indirect ways. Here, we investigated the shift of bacterial communities in two different seaweed samples along with incubation and exposure duration to seashore using 16S rRNA gene-based amplicon sequencing. Bacterial communities belonging to the phyla Proteobacteria and Bacteroidetes are the most abundant on seaweeds surface. Bacterial diversity in Ulva pertusa is increased along with distances from seashore while that of Sargassum horneri are similar. Remarkably, Cobetia sp. having alginate-degrading activity represent with high proportion about 80% in. Also, the abundance of Agar-Degrading Bacteria(ADB) are fluctuated with incubation periods in mesocosm experiment, ADB predominantly present after 7 days incubation while ADB are reduced their portion after 18 days. These features would be consequences of seaweed importance to proper periods reached land. To understand the functional roles of associated bacteria in seaweeds, combined further studies should be performed coping with biochemical, physiological and microbiological approach.