A Preliminary Assessment of the Spatial Distribution and Diversity of Microbial Assemblages within an Inland Salt Marsh in South-eastern Michigan, USA

Microbial communities in the sediments of an inland salt marsh adjacent to a freshwater environment were examined in three locations using high-resolution 16s rRNA gene sequencing approach as well as community diversity analyses. The three sites within the marsh were specifically selected based on their locations relative to the frequently influential Maple River system. In general, a slight biogeographical effect was observed in the relative abundance of most of the bacterial taxa among the sites. Bacterial members belonging to the Proteobacteria, Chloroflexi and Bacteroidetes numerically dominated the sequences among the three sites. The Bacterial Community Compositions (BCC) were more similar among the two sites closer to the adjacent Maple River with the predominance of taxa more commonly found in freshwater habitats such as the Betaproteobacteria, in contrast to the third site within the epicenter of the marsh. These results suggest that frequent flooding from the Maple River probably serves as one of the major determinants of bacterial composition across the entire marsh. The study further revealed the strength of applying the sequencing approach in delineating the community compositions of a previously uncharacterized environment