2024 Abstracts

Soil Bacterial Community Structure and Core Membership Along a Terrestrial-Aquatic Interface of a Freshwater and Estuarine Coastal System


Sreejata Bandopadhyay1* (sreejata.bandopadhyay@pnnl.gov), Kaizad F. Patel1, Pamela Weisenhorn2, Shan Thomas3, Trisha Spanbauer3, Mike Weintraub3, Vanessa L. Bailey1


1Pacific Northwest National Laboratory, Richland, WA; 2Argonne National Laboratory, Lemont, IL; 3University of Toledo, Toledo, OH



Coastal systems are dynamic environments where the intensity and duration of water exposure on soil sediments can create unique microbial niches. Microbial function is also affected by the vegetation in these systems, which vary along the coast ranging from densely vegetated upland areas to moderate and sparse vegetation in transition and wetland zones. Much of the complexity of coastal terrestrial-aquatic interfaces (TAIs) arises from the interactions among water, plants, and soils that contribute to microbial activity and biogeochemical cycling. The objective of this study was to characterize the soil bacterial communities along the coastal TAIs of a freshwater (Western Lake Erie Basin; WLE) and estuarine (Chesapeake Bay; CB) region. Soils were collected from upland, transition, and wetland transects at three sites in each region, and 16S rRNA gene amplicon sequencing was conducted. Researchers found a statistically significant effect of not only region but also transect and site on the soil bacterial communities with significant interaction effects between these factors. Within a region, the team elaborates on bacterial indicator taxa and potential functions that are uniquely associated with specific transects, as well as those taxa that are conserved across transects and defined as the “core” microbiome. Furthermore, both bacterial richness and diversity increased along the transects from upland to wetland areas in both CB and WLE. Combining these patterns with soil chemistry data, researchers found that the bacterial community in upland CB significantly correlated with phosphate ion concentration while wetland communities correlated strongly with sulfate ion concentration in both CB and WLE. Overall, the characterization of the bacterial communities across the TAIs of CB and WLE reveals important members of the soil microbiome, providing potential targets for screening in other omics datasets such as metagenomes.