COMPOSITION AND FUNCTION OF MICROBIAL COMMUNITIES COLONIZING ORGANIC SUBSTRATES ALONG A RURAL TO URBAN GRADIENT
Urbanization is increasing worldwide, and lotic ecosystems are especially susceptible to alterations collectively known as the urban stream syndrome, which include altered hydrology and increased concentrations of nutrients and contaminants. Impacts of urbanization on macroinvertebrates and fish have been documented, but implications for microbial communities are not as well understood. To address this knowledge gap we incubated organic substrates (cotton and silk strips, representing low and high nitrogen substrates, respectively) in 18 streams located along a rural to urban gradient in northeast Ohio, USA. Strips were fixed in the water column of each stream for two months and then analyzed for tensile strength (as an indicator of decomposition) and the taxonomic composition of attached microbial communities (via high-throughput amplicon sequencing). Nitrate concentrations in the streams ranged from 0.06 to 0.68 mg-N L-1. Microbial communities on cotton vs silk substrates were not significantly different in taxonomic diversity but were significantly different in taxonomic composition, suggesting that substrate nitrogen content may be a key driver of microbial community composition in these streams.
Paul Risteca (Primary Presenter/Author), Dept. of Biology, Loyola University Chicago, firstname.lastname@example.org;
Andrea Fitzgibbon ( Co-Presenter/Co-Author), Kent State University , email@example.com;
David Costello ( Co-Presenter/Co-Author), Kent State University, firstname.lastname@example.org;
Scott Tiegs ( Co-Presenter/Co-Author), Dept. of Biological Sciences, Oakland University, email@example.com;
John Kelly ( Co-Presenter/Co-Author), Department of Biology, Loyola University Chicago, Chicago, IL, USA, Jkelly7@luc.edu;