• Publications
  • Influence
Ubiquity and diversity of ammonia-oxidizing archaea in water columns and sediments of the ocean.
Using PCR primers designed to specifically target archaeal amoA, AOA is found to be pervasive in areas of the ocean that are critical for the global nitrogen cycle, including the base of the euphotic zone, suboxic water columns, and estuarine and coastal sediments. Expand
Relative abundance and diversity of ammonia-oxidizing archaea and bacteria in the San Francisco Bay estuary.
This study significantly enhances the understanding of estuarine ammonia-oxidizing microbial communities and highlights the environmental conditions and niches under which different AOA and beta-AOB phylotypes may thrive. Expand
Genome of a Low-Salinity Ammonia-Oxidizing Archaeon Determined by Single-Cell and Metagenomic Analysis
The genome of a novel group of ammonia-oxidizing archaea from low-salinity sediments in San Francisco Bay is sequenced using single-cell and metagenomic genome sequence data and appears to be motile, based on the presence of numerous motility- and chemotaxis-associated genes in the genome. Expand
New processes and players in the nitrogen cycle: the microbial ecology of anaerobic and archaeal ammonia oxidation
What is currently known about the microbial ecology of anaerobic and archaeal ammonia oxidation is reviewed, relevant unknowns are highlighted, and the implications of these discoveries for the global nitrogen and carbon cycles are discussed. Expand
Occurrence of Ammonia-Oxidizing Archaea in Wastewater Treatment Plant Bioreactors
Using PCR primers targeting archaeal ammonia monooxygenase subunit A (amoA) genes, molecular evidence that ammonia-oxidizing archaea (AOA) occur in activated sludge bioreactors used to remove ammonia from wastewater is reported. Expand
Activity, abundance and diversity of nitrifying archaea and bacteria in the central California Current.
Natural abundance stable isotope ratios in nitrate (NO(3)(-)) and nitrous oxide (N(2)O) were used to evaluate the importance of nitrification over longer time scales and calculate that nitrification could produce between 0.45 and 2.93 micromol m(-2) day(-1) N( 2)O in the central California Current. Expand
Molecular and biogeochemical evidence for ammonia oxidation by marine Crenarchaeota in the Gulf of California
Direct quantification of ammonia oxidation rates by 15N labeling, and AOA and AOB abundances by quantitative PCR analysis of ammonia monooxygenase subunit A (amoA) genes, in the Gulf of California represent compelling evidence for an archaeal role in oceanic nitrification. Expand
Diversity of Ammonia-Oxidizing Archaea and Bacteria in the Sediments of a Hypernutrified Subtropical Estuary: Bahía del Tóbari, Mexico
  • J. Beman, C. Francis
  • Medicine, Biology
  • Applied and Environmental Microbiology
  • 29 September 2006
These findings represent the first detailed examination of archaeal amoA diversity in estuarine sediments and demonstrate that diverse communities of Crenarchaeota capable of ammonia oxidation are present within estuaries, where they may be actively involved in nitrification. Expand
Shifts in the relative abundance of ammonia-oxidizing bacteria and archaea across physicochemical gradients in a subterranean estuary.
Analysis of ammonia-oxidizing enrichment cultures at a range of salinities revealed that AOA persisted solely in the freshwater enrichments where they actively express amoA, and offer new insights into the ecology of AOA and beta-AOB by elucidating conditions that may favour the numerical dominance of beta- AOB over AOA in coastal sediments. Expand