ORCID Profile
0000-0001-5914-9107
Current Organisation
University of California Santa Barbara
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Publisher: Wiley
Date: 16-09-2011
Publisher: Springer Science and Business Media LLC
Date: 20-02-2010
Publisher: Springer Science and Business Media LLC
Date: 10-2008
DOI: 10.1038/NATURE07346
Publisher: American Chemical Society (ACS)
Date: 04-03-2019
Abstract: Industrial-scale dumping of organic waste to the deep ocean was once common practice, leaving a legacy of chemical pollution for which a paucity of information exists. Using a nested approach with autonomous and remotely operated underwater vehicles, a dumpsite offshore California was surveyed and s led. Discarded waste containers littered the site and structured the suboxic benthic environment. Dichlorodiphenyltrichloroethane (DDT) was reportedly dumped in the area, and sediment analysis revealed substantial variability in concentrations of p, p-DDT and its analogs, with a peak concentration of 257 μg g
Publisher: Springer Science and Business Media LLC
Date: 12-03-2008
DOI: 10.1038/NATURE06810
Abstract: Microbial activities shape the biogeochemistry of the planet and macroorganism health. Determining the metabolic processes performed by microbes is important both for understanding and for manipulating ecosystems (for ex le, disruption of key processes that lead to disease, conservation of environmental services, and so on). Describing microbial function is h ered by the inability to culture most microbes and by high levels of genomic plasticity. Metagenomic approaches analyse microbial communities to determine the metabolic processes that are important for growth and survival in any given environment. Here we conduct a metagenomic comparison of almost 15 million sequences from 45 distinct microbiomes and, for the first time, 42 distinct viromes and show that there are strongly discriminatory metabolic profiles across environments. Most of the functional ersity was maintained in all of the communities, but the relative occurrence of metabolisms varied, and the differences between metagenomes predicted the biogeochemical conditions of each environment. The magnitude of the microbial metabolic capabilities encoded by the viromes was extensive, suggesting that they serve as a repository for storing and sharing genes among their microbial hosts and influence global evolutionary and metabolic processes.
Publisher: Elsevier BV
Date: 2012
Publisher: Springer Science and Business Media LLC
Date: 03-2008
DOI: 10.1038/NATURE06735
Abstract: Viruses, and more particularly phages (viruses that infect bacteria), represent one of the most abundant living entities in aquatic and terrestrial environments. The biogeography of phages has only recently been investigated and so far reveals a cosmopolitan distribution of phage genetic material (or genotypes). Here we address this cosmopolitan distribution through the analysis of phage communities in modern microbialites, the living representatives of one of the most ancient life forms on Earth. On the basis of a comparative metagenomic analysis of viral communities associated with marine (Highborne Cay, Bahamas) and freshwater (Pozas Azules II and Rio Mesquites, Mexico) microbialites, we show that some phage genotypes are geographically restricted. The high percentage of unknown sequences recovered from the three metagenomes (>97%), the low percentage similarities with sequences from other environmental viral (n = 42) and microbial (n = 36) metagenomes, and the absence of viral genotypes shared among microbialites indicate that viruses are genetically unique in these environments. Identifiable sequences in the Highborne Cay metagenome were dominated by single-stranded DNA microphages that were not detected in any other s les examined, including sea water, fresh water, sediment, terrestrial, extreme, metazoan-associated and marine microbial mats. Finally, a marine signature was present in the phage community of the Pozas Azules II microbialites, even though this environment has not been in contact with the ocean for tens of millions of years. Taken together, these results prove that viruses in modern microbialites display biogeographical variability and suggest that they may be derived from an ancient community.
Publisher: American Geophysical Union (AGU)
Date: 11-2007
DOI: 10.1029/2007GL031344
Publisher: Springer Science and Business Media LLC
Date: 25-04-2010
DOI: 10.1038/NGEO848
Publisher: Wiley
Date: 03-2012
Location: United States of America
Location: United States of America
No related grants have been discovered for David Valentine.