Seasonal Variations in Bacterial Communities Associated with Seawaters From Tongyeong in South Sea of Korea.

Abstract

Understanding patterns of microbial diversity and composition in the seawater is essential to assess the impact of microbes on marine ecosystem. Also could be base of farther study. Although the potential roles of microbes in ocean were revealed, their diversity and relationships with environmental factors are still unclear. In this study, we used a 16S rRNA gene taq-pyrosequencing technique to investigate the bacterial communities associated with two different seasonal seawater samples from South Sea of Korea in Tongyeong. Our results showed 1160 and 1650 Operational Taxonomic Units (OTUs) were found at each sampling times, March and May. Environment conditions differed significantly, Bacteria composition also changed. Altogether, 27 bacterial phyla were recovered from the both seawaters, of which Proteobacteria was the most dominant group. In addition, the value of Shannon index, which measures the evenness of the distribution of individuals among OTUs, of seawater in May is higher than that in March which means in May displays a higher diversity of bacteria. An interest thing is that the proportion of pathogenic bacteria was significantly increased in May relative to March. In particular, Pseudoalteromona, Aliivibrio, Coxiella and Vibrio have been detected as pathogenic bacteria from both seawaters, and of which Vibrios were dominant.ealed, their diversity and relationships with environmental factors are still unclear. In this study, we used a 16S rRNA gene taq-pyrosequencing technique to investigate the bacterial communities associated with two different seasonal seawater samples from South Sea of Korea in Tongyeong. Our results showed 1160 and 1650 Operational Taxonomic Units (OTUs) were found at each sampling times, March and May. Environment conditions differed significantly, Bacteria composition also changed. Altogether, 27 bacterial phyla were recovered from the both seawaters, of which Proteobacteria was the most dominant group. In addition, the value of Shannon index, which measures the evenness of the distribution of individuals among OTUs, of seawater in May is higher than that in March which means in May displays a higher diversity of bacteria. An interest thing is that the proportion of pathogenic bacteria was significantly increased in May relative to March. In particular, Pseudoalteromona, Aliivibrio, Coxiella and Vibrio have been detected as pathogenic bacteria from both seawaters, and of which Vibrios were dominant.