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Full-Text Articles in Marine Biology

Population Dynamics And Community Composition Of Ammonia Oxidizers In Salt Marshes After The Deepwater Horizon Oil Spill, Anne E. Bernhard, Roberta Sheffer, Anne E. Giblin, John M. Marton, Brian J. Roberts Jun 2016

Population Dynamics And Community Composition Of Ammonia Oxidizers In Salt Marshes After The Deepwater Horizon Oil Spill, Anne E. Bernhard, Roberta Sheffer, Anne E. Giblin, John M. Marton, Brian J. Roberts

Biology Faculty Publications

The recent oil spill in the Gulf of Mexico had significant effects on microbial communities in the Gulf, but impacts on nitrifying communities in adjacent salt marshes have not been investigated. We studied persistent effects of oil on ammonia-oxidizing archaeal (AOA) and bacterial (AOB) communities and their relationship to nitrification rates and soil properties in Louisiana marshes impacted by the Deepwater Horizon oil spill. Soils were collected at oiled and unoiled sites from Louisiana coastal marshes in July 2012, 2 years after the spill, and analyzed for community differences based on ammonia monooxygenase genes (amoA). Terminal Restriction Fragment …


Long-Term Impacts Of Disturbance On Nitrogen-Cycling Bacteria In A New England Salt Marsh, Anne E. Bernhard, Courtney Dwyer, Adrian Idrizi, Geoffrey Bender, Rachel Zwick Feb 2015

Long-Term Impacts Of Disturbance On Nitrogen-Cycling Bacteria In A New England Salt Marsh, Anne E. Bernhard, Courtney Dwyer, Adrian Idrizi, Geoffrey Bender, Rachel Zwick

Biology Faculty Publications

Recent studies on the impacts of disturbance on microbial communities indicate communities show differential responses to disturbance, yet our understanding of how different microbial communities may respond to and recover from disturbance is still rudimentary. We investigated impacts of tidal restriction followed by tidal restoration on abundance and diversity of denitrifying bacteria, ammonia-oxidizing bacteria (AOB), and ammonia-oxidizing archaea (AOA) in New England salt marshes by analyzing nirS and bacterial and archaeal amoA genes, respectively. TRFLP analysis of nirS and betaproteobacterial amoA genes revealed significant differences between restored and undisturbed marshes, with the greatest differences detected in …


Increased Variability Of Microbial Communities In Restored Salt Marshes Nearly 30 Years After Tidal Flow Restoration, Anne E. Bernhard, David Marshall, Lazaros Yiannos Jan 2012

Increased Variability Of Microbial Communities In Restored Salt Marshes Nearly 30 Years After Tidal Flow Restoration, Anne E. Bernhard, David Marshall, Lazaros Yiannos

Biology Faculty Publications

We analyzed microbial diversity and community composition from four salt marsh sites that were impounded for 40–50 years and subsequently restored and four unimpounded sites in southeastern Connecticut over one growing season. Community composition and diversity were assessed by terminal restriction fragment length polymorphism (TRFLP) and sequence analysis of 16S ribosomal RNA (rRNA) genes. Our results indicated diverse communities, with sequences representing 14 different bacterial divisions. Proteobacteria, Bacteroidetes, and Planctomycetes dominated clone libraries from both restored and unimpounded sites. Multivariate analysis of the TRFLP data suggest significant site, sample date, and restoration status effects, but the exact causes of these …


Estuarine Nitrifiers: New Players, Patterns And Processes, Anne E. Bernhard, Annette Bollmann Jun 2010

Estuarine Nitrifiers: New Players, Patterns And Processes, Anne E. Bernhard, Annette Bollmann

Biology Faculty Publications

Ever since the first descriptions of ammonia-oxidizing Bacteria by Winogradsky in the late 1800s, the metabolic capability of aerobic ammonia oxidation has been restricted to a phylogenetically narrow group of bacteria. However, the recent discovery of ammonia-oxidizing Archaea has forced microbiologists and ecologists to re-evaluate long-held paradigms and the role of niche partitioning between bacterial and archaeal ammonia oxidizers. Much of the current research has been conducted in open ocean or terrestrial systems, where community patterns of archaeal and bacterial ammonia oxidizers are highly congruent. Studies of archaeal and bacterial ammonia oxidizers in estuarine systems, however, present a very different …