Relationship between Sediment Characteristics and Microbial Community Structure in Tidal Flats of Aki Nada

Abstract

The investigations were carried out in 35 sites of 4 tidal flats located in Aki Nada of the Seto Inland Sea, Japan, from May 2012 until July 2012 to clarify the relationship between sediment characteristics and microbial community structure. This study focused on microbial community structure and particle size distribution. Microbial community structure was analyzed by a quinone profile. Cluster analysis and principal component analysis of sediments were conducted using particle size distribution, pH, ignition loss (IL), and water content. The sediments were classified into 6 groups by the physicochemical characteristics of sediments, mainly very coarse sand and silt+clay. The most dominant ubiquinone species in Clusters 1-5 and Cluster 6 were UQ-8 and UQ-10, respectively. Cluster 6 was the highest in silt+clay content. Cluster 4 and 6 with high IL included MK-7 (H 6 ). Distribution of microbial community structure in sediments of tidal flats can be explained by the classified physicochemical characteristics of sediments. These results contribute to our understanding of the microbial ecosystem in Aki Nada.