Meeting Abstract

105.5  Tuesday, Jan. 7 09:00  Identifying gut microbiota in ribbed mussels with next-generation sequencing MOORE, SR*; MOSEMAN-VALTIERRA, SM; GOVENAR, B; Rhode Island College; Univ. of Rhode Island; Rhode Island College smoore_6564@email.ric.edu

Salt marshes have been considered as sinks for greenhouse gas emissions, but under conditions of climate change, may instead act as sources of carbon dioxide, methane, and nitrous oxide. As part of a larger project to understand the shifts in trophic dynamics and greenhouse gas fluxes that result from elevated temperatures and nutrient levels in estuaries, we are investigating the composition of bacteria and archaea in the gut contents of the dominant benthic invertebrate, the ribbed mussel Geukensia demissa, in coastal salt marshes, along the historic nitrogen-loading gradient in Narragansett Bay, Rhode Island. In 2012, we collected mussels from two marshes where greenhouse gas fluxes were measured. Then, in the laboratory, we dissected the digestive tract to extract DNA from different regions from the stomach and intestine to test the hypotheses that 1) the diet of the mussels would vary along the nitrogen-loading gradient, and 2) the foregut would include a greater proportion of ingested bacteria capable of denitrification and the hindgut would include a greater proportion of resident methanogens. From DNA extractions, we used PCR to amplify the V4 hypervariable region of the 16S ribosomal RNA gene for next-generation sequencing for taxonomic classification and comparison of microbial diversity, and we will use qPCR to quantify the abundance of denitrifiers and methanogens. This work will help us to identify the role of the gut microbiota in ribbed mussels in contributing to their nutrition and the shifts in greenhouse gas fluxes resulting from impacts of climate change in Narragansett Bay.