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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
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
Isotopic Signature of N2O Produced by Marine Ammonia-Oxidizing Archaea
Natural-abundance stable isotope measurements indicate that the produced N2O had bulk δ15N and δ18O values higher than observed for ammonia-oxidizing bacteria but similar to the values attributed to the oceanic N 2O source to the atmosphere. 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
Beach sands along the California coast are diffuse sources of fecal bacteria to coastal waters.
The decrease in nearshore ENT concentrations after the initial influx can be explained by ENT die-off and dilution with clean ocean water, and the presence of a putative bacterial source, degree of wave shelter, and surrounding land use explained a significant fraction of the variation in both ENT and EC densities between beaches. Expand
Denitrifier Community Composition along a Nitrate and Salinity Gradient in a Coastal Aquifer
The denitrifying community within the beach aquifer at Huntington Beach, California, is examined, finding taxonomically rich and novel communities, with all nirK clones exhibiting <85% identity and nirS clones exhibiting<92% identity at the amino acid level to those of cultivated denitRifiers and other environmental clones in the database. Expand
Enrichment and characterization of ammonia-oxidizing archaea from the open ocean: phylogeny, physiology and stable isotope fractionation
Three strains of pelagic ammonia-oxidizing archaea from the North Pacific Ocean that have been maintained in laboratory culture for over 3 years are reported, indicating they belong to a previously identified clade of water column-associated AOA and possess 16S ribosomal RNA genes and ammonia monooxygenase subunit a genes highly similar to those recovered in DNA and complementary DNA clone libraries from the open ocean. Expand
Oxygen isotopic composition of nitrate and nitrite produced by nitrifying cocultures and natural marine assemblages
The d18O value of nitrate produced during nitrification (d 18 ONO3,nit) was measured in experiments designed to mimic oceanic conditions, involving cocultures of ammonia-oxidizing bacteria orExpand
Genomic and proteomic characterization of “Candidatus Nitrosopelagicus brevis”: An ammonia-oxidizing archaeon from the open ocean
A closed genome assembled from a highly enriched culture of the ammonia-oxidizing pelagic thaumarchaeon CN25, originating from the open ocean, exhibits strong evidence of genome streamlining, including a 1.23-Mbp genome, a high coding density, and a low number of paralogous genes. Expand
Interactions between fire and bark beetles in an old growth pine forest
Ips bark beetles can exert meaningful effects on the survivorship of red pine populations, and their demographic impact is probably increased by ground fires. Expand