In situ enrichment of ocean crust microbes on igneous minerals and glasses using an osmotic flow-through device

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doi: 10.1029/2010GC003424
Author(s): Smith, Amy; Popa, Radu; Fisk, Martin R.; Nielsen, Mark E.; Wheat, C. Geoffrey; Jannasch, Hans W.; Fisher, Andrew T.; Becker, Keir; Sievert, Stefan M.; Flores, Gilberto
Author Affiliation(s): Primary:
Portland State University, Department of Biology, Portland, OR, United States
Other:
Oregon State University, United States
Harvard University, United States
University of Alaska at Fairbanks, United States
Monterey Bay Aquarium Research Institute, United States
University of California at Santa Cruz, United States
University of Miami, United States
Woods Hole Oceanographic Institution, United States
Volume Title: Geochemistry, Geophysics, Geosystems - G<sup>3</sup>
Source: Geochemistry, Geophysics, Geosystems - G>3`, 12(6). Publisher: American Geophysical Union and The Geochemical Society, United States. ISSN: 1525-2027
Note: In English. 70 refs.; illus., incl. 5 tables, sketch map
Summary: The Integrated Ocean Drilling Program (IODP) Hole 1301A on the eastern flank of Juan de Fuca Ridge was used in the first long-term deployment of microbial enrichment flow cells using osmotically driven pumps in a subseafloor borehole. Three novel osmotically driven colonization systems with unidirectional flow were deployed in the borehole and incubated for 4 years to determine the microbial colonization preferences for 12 minerals and glasses present in igneous rocks. Following recovery of the colonization systems, we measured cell density on the minerals and glasses by fluorescent staining and direct counting and found some significant differences between mineral samples. We also determined the abundance of mesophilic and thermophilic culturable organotrophs grown on marine R2A medium and identified isolates by partial 16S or 18S rDNA sequencing. We found that nine distinct phylotypes of culturable mesophilic oligotrophs were present on the minerals and glasses and that eight of the nine can reduce nitrate and oxidize iron. Fe(II)-rich olivine minerals had the highest density of total countable cells and culturable organotrophic mesophiles, as well as the only culturable organotrophic thermophiles. These results suggest that olivine (a common igneous mineral) in seawater-recharged ocean crust is capable of supporting microbial communities, that iron oxidation and nitrate reduction may be important physiological characteristics of ocean crust microbes, and that heterogeneously distributed minerals in marine igneous rocks likely influence the distribution of microbial communities in the ocean crust.
Year of Publication: 2011
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Bacteria; Crust; DNA; East Pacific; Endeavour Ridge; Expedition 301; Glasses; IODP Site U1301; Igneous rocks; Instruments; Integrated Ocean Drilling Program; Iron; Juan de Fuca Ridge; Metals; Microorganisms; Minerals; Nitrates; North Pacific; Northeast Pacific; Nucleic acids; ODP Site 1026; Ocean Drilling Program; Ocean floors; Oceanic crust; Organic acids; Organic compounds; Osmosis; Oxidation; Pacific Ocean; Techniques; Volcanic rocks; Weathering
Coordinates: N474556 N474556 W1274526 W1274526
N474500 N474600 W1274600 W1274600
Record ID: 2012021832
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