• Publications
  • Influence
Nitrogen fixation and transfer in open ocean diatom–cyanobacterial symbioses
Many diatoms that inhabit low-nutrient waters of the open ocean live in close association with cyanobacteria. Some of these associations are believed to be mutualistic, where N2-fixing cyanobacterialExpand
Influence of the Amazon River plume on distributions of free-living and symbiotic cyanobacteria in the western tropical north Atlantic Ocean
The vertical and horizontal distributions of seven diazotrophic populations in the western tropical north Atlantic (WTNA) Ocean were examined using a nifH DNA quantitative polymerase chain reactionExpand
Metabolic streamlining in an open-ocean nitrogen-fixing cyanobacterium
Nitrogen (N2)-fixing marine cyanobacteria are an important source of fixed inorganic nitrogen that supports oceanic primary productivity and carbon dioxide removal from the atmosphere. A globallyExpand
Unicellular Cyanobacterium Symbiotic with a Single-Celled Eukaryotic Alga
Fixing on a Marine Partnership Nitrogen fixation by microorganisms determines the productivity of the biosphere. Although plants photosynthesize by virtue of the ancient incorporation ofExpand
Nitrogen fixation by unicellular diazotrophic cyanobacteria in the temperate oligotrophic North Pacific Ocean
N2 fixation has been understudied in marine environments outside of the subtropical and tropical oceans and where water temperatures are typically below 20–25uC. We identified nifH phylotypes andExpand
Seasonality of N2 fixation and nifH gene diversity in the Gulf of Aqaba (Red Sea)
Nitrogen (N2) fixation rates were determined on bulk water collected in the Gulf of Aqaba, Red Sea, during fall (stratified, oligotrophic) and spring (deep mixing, mesotrophic) seasons. N2 fixationExpand
Database of diazotrophs in global ocean: abundance, biomass and nitrogen fixation rates
Abstract. Marine N2 fixing microorganisms, termed diazotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N2) to bioavailable nitrogen provides anExpand
Detecting metabolic activities in single cells, with emphasis on nanoSIMS.
Investigating the contribution of microbial populations to biochemical processes of global significance is challenging as there are few approaches that can detect microbial metabolic activities onExpand
In situ identification and N₂ and C fixation rates of uncultivated cyanobacteria populations.
Nitrogen (N₂) fixation is a globally important process often mediated by diazotrophic cyanobacteria in the open ocean. In 2010, seawater was collected near Cape Verde to identify and measure N₂ andExpand
Distribution and activity of diazotrophs in the Eastern Equatorial Atlantic
The gene abundance and gene expression of six diazotroph populations from the Eastern Equatorial Atlantic in June 2007 were examined using nifH gene quantitative polymerase chain reaction (q PCR)Expand