Characterization of bacterial communities associated with seasonal water masses from Tongyoung in South Sea of Korea

Abstract

 Understanding the patterns of microbial diversity and their composition in seawater is necessary to assess the impacts of microbes on marine ecosystem. Although the potential roles of microbes in the ocean have been studied, their diversity and relationship with environmental factors remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with two different water masses from Tongyoung in the South Sea of Korea. Our results revealed highly diverse bacterial communities up to 900 Operational Taxonomic Units (OTUs) estimated from each seawater which was collected in the month of March and May, when the environmental conditions including temperature differed significantly: 7.2°C and 17.6°C in March and May, respectively. Altogether, 13 bacterial phyla were recovered from the seawater, of which Proteobacteria was the most dominant group. In addition, the value of the Shannon index, which measures the evenness of the distribution of individuals among OTUs, in May is higher than that in March, indicating that it displays a wider diversity of bacteria. Interestingly, the proportion of pathogenic bacteria was significantly increased in the month of May compared to March, suggesting that pathogenic bacteria were increasingly emerging in May. In particular, Pseudoalteromonas and Vibrio spp. were determined as major pathogenic bacteria from both water masses, of which Vibrio spp. were dominant.

Microbiota Composition and Pulmonary Surfactant Protein Expression as Markers of Death by Drowning

“…The bacterial composition of the drowning medium samples was analyzed, and Proteobacteria generally predominated in both freshwater and seawater. These results are in agreement with previous reports of the microbial community of seawater and freshwater . Representative freshwater bacteria, such as the families Flavobacteriaceae and Planktophilia_f, were detected in the Han River sample.…”

Analysis of Microbial Composition Associated with Freshwater and Seawater

“…The dominant phyla in all the water samples were Proteobacteria, Bacteroidetes, and Actinobacteria. These results were similar to those shown by previous studies of the microbial communities in seawater (Bolhuis and Stal, 2011;Suh et al, 2014;Suh et al, 2015).…”