Paulsen Ian T.

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Ian T.

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  • Article
    Genome of the epsilonproteobacterial chemolithoautotroph Sulfurimonas denitrificans
    (American Society for Microbiology, 2007-12-07) Sievert, Stefan M. ; Scott, Kathleen M. ; Klotz, Martin G. ; Chain, Patrick S. G. ; Hauser, Loren J. ; Hemp, James ; Hugler, Michael ; Land, Miriam L. ; Lapidus, Alla ; Larimer, Frank W. ; Lucas, Susan ; Malfatti, Stephanie A. ; Meyer, Folker ; Paulsen, Ian T. ; Ren, Qinghu ; Simon, Jörg ; USF Genomics Class
    Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This genome has many features, including a larger size (2.2 Mbp), that suggest a greater degree of metabolic versatility or responsiveness to the environment than seen for most of the other sequenced epsilonproteobacteria. A branched electron transport chain is apparent, with genes encoding complexes for the oxidation of hydrogen, reduced sulfur compounds, and formate and the reduction of nitrate and oxygen. Genes are present for a complete, autotrophic reductive citric acid cycle. Many genes are present that could facilitate growth in the spatially and temporally heterogeneous sediment habitat from where Sulfurimonas denitrificans was originally isolated. Many resistance-nodulation-development family transporter genes (10 total) are present; of these, several are predicted to encode heavy metal efflux transporters. An elaborate arsenal of sensory and regulatory protein-encoding genes is in place, as are genes necessary to prevent and respond to oxidative stress.
  • Article
    The genome of deep-sea vent chemolithoautotroph Thiomicrospira crunogena XCL-2
    (Public Library of Science (PLoS), 2006-11-14) Scott, Kathleen M. ; Sievert, Stefan M. ; Abril, Fereniki N. ; Ball, Lois A. ; Barrett, Chantell J. ; Blake, Rodrigo A. ; Boller, Amanda J. ; Chain, Patrick S. G. ; Clark, Justine A. ; Davis, Carisa R. ; Detter, Chris ; Do, Kimberly F. ; Dobrinski, Kimberly P. ; Faza, Brandon I. ; Fitzpatrick, Kelly A. ; Freyermuth, Sharyn K. ; Harmer, Tara L. ; Hauser, Loren J. ; Hugler, Michael ; Kerfeld, Cheryl A. ; Klotz, Martin G. ; Kong, William W. ; Land, Miriam L. ; Lapidus, Alla ; Larimer, Frank W. ; Longo, Dana L. ; Lucas, Susan ; Malfatti, Stephanie A. ; Massey, Steven E. ; Martin, Darlene D. ; McCuddin, Zoe ; Meyer, Folker ; Moore, Jessica L. ; Ocampo, Luis H. ; Paul, John H. ; Paulsen, Ian T. ; Reep, Douglas K. ; Ren, Qinghu ; Ross, Rachel L. ; Sato, Priscila Y. ; Thomas, Phaedra ; Tinkham, Lance E. ; Zeruth, Gary T.
    Presented here is the complete genome sequence of Thiomicrospira crunogena XCL-2, representative of ubiquitous chemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-sea hydrothermal vents. This gammaproteobacterium has a single chromosome (2,427,734 base pairs), and its genome illustrates many of the adaptations that have enabled it to thrive at vents globally. It has 14 methyl-accepting chemotaxis protein genes, including four that may assist in positioning it in the redoxcline. A relative abundance of coding sequences (CDSs) encoding regulatory proteins likely control the expression of genes encoding carboxysomes, multiple dissolved inorganic nitrogen and phosphate transporters, as well as a phosphonate operon, which provide this species with a variety of options for acquiring these substrates from the environment. Thiom. crunogena XCL-2 is unusual among obligate sulfur-oxidizing bacteria in relying on the Sox system for the oxidation of reduced sulfur compounds. The genome has characteristics consistent with an obligately chemolithoautotrophic lifestyle, including few transporters predicted to have organic allocrits, and Calvin-Benson-Bassham cycle CDSs scattered throughout the genome.
  • Preprint
    Niche of harmful alga Aureococcus anophagefferens revealed through ecogenomics
    ( 2011-01) Gobler, Christopher J. ; Berry, Dianna L. ; Dyhrman, Sonya T. ; Wilhelm, Steven W. ; Salamov, Asaf ; Lobanov, Alexei V. ; Zhang, Yan ; Collier, Jackie L. ; Wurch, Louie L. ; Kustka, Adam B. ; Dill, Brian D. ; Shah, Manesh ; VerBerkmoes, Nathan C. ; Kuo, Alan J. ; Terry, Astrid ; Pangilinan, Jasmyn ; Lindquist, Erika A. ; Lucas, Susan ; Paulsen, Ian T. ; Hattenrath-Lehmann, Theresa K. ; Talmage, Stephanie C. ; Walker, Elyse A. ; Koch, Florian ; Burson, Amanda M. ; Marcoval, Maria Alejandra ; Tang, Ying-Zhong ; LeCleir, Gary R. ; Coyne, Kathryn J. ; Berg, Gry M. ; Bertrand, Erin M. ; Saito, Mak A. ; Gladyshev, Vadim N. ; Grigoriev, Igor V.
    Harmful algal blooms (HABs) cause significant economic and ecological damage worldwide. Despite considerable efforts, a comprehensive understanding of the factors that promote these blooms has been lacking because the biochemical pathways that facilitate their dominance relative to other phytoplankton within specific environments have not been identified. Here, biogeochemical measurements demonstrated that the harmful 43 Aureococcus anophagefferens outcompeted co-occurring phytoplankton in estuaries with elevated levels of dissolved organic matter and turbidity and low levels of dissolved inorganic nitrogen. We subsequently sequenced the first HAB genome (A. anophagefferens) and compared its gene complement to those of six competing phytoplankton species identified via metaproteomics. Using an ecogenomic approach, we specifically focused on the gene sets that may facilitate dominance within the environmental conditions present during blooms. A. anophagefferens possesses a larger genome (56 mbp) and more genes involved in light harvesting, organic carbon and nitrogen utilization, and encoding selenium- and metal-requiring enzymes than competing phytoplankton. Genes for the synthesis of microbial deterrents likely permit the proliferation of this species with reduced mortality losses during blooms. Collectively, these findings suggest that anthropogenic activities resulting in elevated levels of turbidity, organic matter, and metals have opened a niche within coastal ecosystems that ideally suits the unique genetic capacity of A. anophagefferens and thus has facilitated the proliferation of this and potentially other HABs.