Characterization of Bacterial Diversity and Pathogenic Bacteria in the Water Masses from Jeju Island in South Korea Using Pyrosequencing

Abstract

Comprehensive study of patterns of microbial diversity and distribution from seawater is necessary for elucidating the impact of microbes on global marine life. Although the potential roles of microbes have been identified, their diversity and relationship with environmental factors such as temperature, salinity, pH and nutrients are still unclear. So, we exploited a 16S rRNA gene taq-pyrosequencing technique to define the bacterial communities associated with two different seasonal seawater samples in Jeju island. Our results showed 831 and 1772 Operational Taxonomic Units (OTUs) in March and May, respectively. Altogether, 36 bacterial phyla were detected from both seawater samples. Among them, Proteobacteria was identified as a most dominant group, representing at least 75%. Moreover, the value of Shannon index, which measures the evenness of the dispersion of individuals among OTUs, of seawater in May is almost two times higher than in March, suggesting that bacterial diversity in may increased compared to that in march. Another interesting point is that proportion of pathogenic bacteria in both seawaters was highly detected, showing that pathogenic bacteria accounted for about 1% of the total. Arcobacter, Roseovarius, Halomonas, Tenacibaculum, Aliivibrio, and Vibrio were found as pathogenic bacteria from both seawater samples, of which Vibrios were dominant.and relationship with environmental factors such as temperature, salinity, pH and nutrients are still unclear. So, we exploited a 16S rRNA gene taq-pyrosequencing technique to define the bacterial communities associated with two different seasonal seawater samples in Jeju island. Our results showed 831 and 1772 Operational Taxonomic Units (OTUs) in March and May, respectively. Altogether, 36 bacterial phyla were detected from both seawater samples. Among them, Proteobacteria was identified as a most dominant group, representing at least 75%. Moreover, the value of Shannon index, which measures the evenness of the dispersion of individuals among OTUs, of seawater in May is almost two times higher than in March, suggesting that bacterial diversity in may increased compared to that in march. Another interesting point is that proportion of pathogenic bacteria in both seawaters was highly detected, showing that pathogenic bacteria accounted for about 1% of the total. Arcobacter, Roseovarius, Halomonas, Tenacibaculum, Aliivibrio, and Vibrio were found as pathogenic bacteria from both seawater samples, of which Vibrios were dominant.