Browsing by Author "Biddle,Jennifer F."
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Item Deep Subsurface Life from North Pond: Enrichment, Isolation, Characterization and Genomes of Heterotrophic Bacteria(Frontiers Media S.A., 5/10/16) Russell,Joseph A.; Leon-Zayas,Rosa; Wrighton,Kelly; Biddle,Jennifer F.; Joseph A. Russell, Rosa Leon-Zayas, Kelly Wrighton and Jennifer F. Biddle; Biddle, Jennifer FrancesStudies of subsurface microorganisms have yielded few environmentally relevant isolates for laboratory studies. In order to address this lack of cultivated microorganisms, we initiated several enrichments on sediment and underlying basalt samples from North Pond, a sediment basin ringed by basalt outcrops underlying an oligotrophic water column west of the Mid-Atlantic Ridge at 22 degrees N. In contrast to anoxic enrichments, growth was observed in aerobic, heterotrophic enrichments from sediment of IODP Hole U1382B at 4 and 68 m below seafloor (mbsf). These sediment depths, respectively, correspond to the fringes of oxygen penetration from overlying seawater in the top of the sediment column and upward migration of oxygen from oxic seawater from the basalt aquifer below the sediment. Here we report the enrichment, isolation, initial characterization and genomes of three isolated aerobic heterotrophs from North Pond sediments; an Arthrobacter species from 4 mbsf, and Paracoccus and Pseudomonas species from 68 mbsf. These cultivated bacteria are represented in the amplicon 16S rRNA gene libraries created from whole sediments, albeit at low (up to 2%) relative abundance. We provide genomic evidence from our isolates demonstrating that the Arthrobacter and Pseudomonas isolates have the potential to respire nitrate and oxygen, though dissimilatory nitrate reduction could not be confirmed in laboratory cultures. The cultures from this study represent members of abundant phyla, as determined by amplicon sequencing of environmental DNA extracts, and allow for further studies into geochemical factors impacting life in the deep subsurface.Item The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation(Frontiers Media Sa, 2/18/16) Teske,Andreas; de Beer,Dirk; McKay,Luke J.; Tivey,Margaret K.; Biddle,Jennifer F.; Hoer,Daniel; Lloyd,Karen G.; Lever,Mark A.; Roy,Hans; Albert,Daniel B.; Mendlovitz,Howard P.; MacGregor,Barbara J.; Andreas Teske, Dirk de Beer, Luke J. McKay, Margaret K. Tivey, Jennifer F. Biddle, Daniel Hoer, Karen G. Lloyd, Mark A. Lever, Hans Roy, Daniel B. Albert, Howard P. Mendlovitz and Barbara J. MacGregor; Biddle, Jennifer FrancesThe hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region.