RT Journal Article
SR Electronic
T1 Nutrient dynamics and stream order influence microbial community patterns along a 2914 km transect of the Mississippi River
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 091512
DO 10.1101/091512
A1 Michael W. Henson
A1 Jordan Hanssen
A1 Greg Spooner
A1 Patrick Fleming
A1 Markus Pukonen
A1 Frederick Stahr
A1 J. Cameron Thrash
YR 2017
UL http://biorxiv.org/content/early/2017/12/23/091512.abstract
AB Draining 31 states and roughly 3 million km2, the Mississippi River (MSR) and its tributaries constitute an essential resource to millions of people for clean drinking water, transportation, agriculture, and industry. Since the turn of the 20th century, MSR water quality has continually rated poorly due to human activity. Acting as first responders, microorganisms can mitigate, exacerbate, and/or serve as predictors for water quality, yet we know little about their community structure or ecology at the whole river scale for large rivers. We collected both biological (16S and 18S rRNA gene amplicons) and physicochemical data from 38 MSR sites over nearly 3000 km from Minnesota to the Gulf of Mexico. Our results revealed a microbial community composed of similar taxa to other rivers but with unique trends in the relative abundance patterns among phyla, OTUs, and the core microbiome. Furthermore, we observed a separation in microbial communities that mirrored the transition from an 8th to 10th Strahler order river at the Missouri River confluence, marking a different start to the lower MSR than the historical distinction at the Ohio River confluence in Cairo, IL. Within MSR microbial assemblages we identified subgroups of OTUs from the phyla Acidobacteria, Bacteroidetes, Oomycetes, and Heterokonts that were associated with, and predictive of, the important eutrophication nutrients nitrate and phosphate. This study offers the most comprehensive view of MSR microbiota to date, provides important groundwork for higher resolution microbial studies of river perturbation, and identifies potential microbial indicators of river health related to eutrophication.