A Microbial Signature Approach to Identify Fecal Pollution in the Waters Off an Urbanized Coast of Lake Michigan Journal Article


Authors: Newton, Ryan J.; Bootsma, Melinda J.; Morrison, Hilary G.; Sogin, Mitchell L.; McLellan, Sandra L.
Article Title: A Microbial Signature Approach to Identify Fecal Pollution in the Waters Off an Urbanized Coast of Lake Michigan
Abstract: Urban coasts receive watershed drainage from ecosystems that include highly developed lands with sewer and stormwater infrastructure. In these complex ecosystems, coastal waters are often contaminated with fecal pollution, where multiple delivery mechanisms that often contain multiple fecal sources make it difficult to mitigate the pollution. Here, we exploit bacterial community sequencing of the V6 and V6V4 hypervariable regions of the bacterial 16S rRNA gene to identify bacterial distributions that signal the presence of sewer, fecal, and human fecal pollution. The sequences classified to three sewer infrastructure-associated bacterial genera, Acinetobacter, Arcobacter, and Trichococcus, and five fecal-associated bacterial families, Bacteroidaceae, Porphyromonadaceae, Clostridiaceae, Lachnospiraceae, and Ruminococcaceae, served as signatures of sewer and fecal contamination, respectively. The human fecal signature was determined with the Bayesian source estimation program SourceTracker, which we applied to a set of 40 sewage influent samples collected in Milwaukee, WI, USA to identify operational taxonomic units (a parts per thousand yen97 % identity) that were most likely of human fecal origin. During periods of dry weather, the magnitudes of all three signatures were relatively low in Milwaukee#39;s urban rivers and harbor and nearly zero in Lake Michigan. However, the relative contribution of the sewer and fecal signature frequently increased to gt; 2 % of the measured surface water communities following sewer overflows. Also during combined sewer overflows, the ratio of the human fecal pollution signature to the fecal pollution signature in surface waters was generally close to that of sewage, but this ratio decreased dramatically during dry weather and rain events, suggesting that nonhuman fecal pollution was the dominant source during these weather-driven scenarios. The qPCR detection of two human fecal indicators, human Bacteroides and Lachno2, confirmed the urban fecal footprint in this ecosystem extends to at least 8 km offshore.
Keywords: WATER; eutrophication; CALIFORNIA; QUALITY; Recreational; GENETIC-MARKERS; SOURCE TRACKING; SEWAGE CONTAMINATION; TREATMENT-PLANT; GUT MICROBIOME; BACTEROIDALES
Journal Title: Microbial Ecology
Volume: 65
Issue: 4
ISSN: 0095-3628
Publisher: Springer Verlag  
Publication Place: NEW YORK; 233 SPRING ST, NEW YORK, NY 10013 USA
Date Published: 2013
Start Page: 1011
End Page: 1023
DOI/URL:
Notes: PT: J; TC: 0; UT: WOS:000318183800024