title: Novel psychropiezophilic Oceanospirillales species Profundimonas piezophila gen. nov., sp. nov., isolated from the deep-sea environment of the Puerto Rico trench.
abstract: The diversity of deep-sea high-pressure-adapted (piezophilic) microbes in isolated monoculture remains low. In this study, a novel obligately psychropiezophilic bacterium was isolated from seawater collected from the Puerto Rico Trench at a depth of ∼6,000 m. This isolate, designated YC-1, grew best in a nutrient-rich marine medium, with an optimal growth hydrostatic pressure of 50 MPa (range, 20 to 70 MPa) at 8°C. Under these conditions, the maximum growth rate was extremely slow, 0.017 h(-1), and the maximum yield was 3.51 × 10(7) cells ml(-1). Cell size and shape changed with pressure, shifting from 4.0 to 5.0 μm in length and 0.5 to 0.8 μm in width at 60 MPa to 0.8- to 1.0-μm diameter coccoid cells under 20 MPa, the minimal pressure required for growth. YC-1 is a Gram-negative, facultatively anaerobic heterotroph. Its predominant cellular fatty acids are the monounsaturated fatty acids (MUFAs) C16:1 and C18:1. Unlike many other psychropiezophiles, YC-1 does not synthesize any polyunsaturated fatty acids (PUFAs). Phylogenetic analysis placed YC-1 within the family of Oceanospirillaceae, closely related to the uncultured symbiont of the deep-sea whale bone-eating worms of the genus Osedax. In common with some other members of the Oceanospirillales, including those enriched during the Deepwater Horizon oil spill, YC-1 is capable of hydrocarbon utilization. On the basis of its characteristics, YC-1 appears to represent both a new genus and a new species, which we name Profundimonas piezophila gen. nov., sp. nov.
authors.affiliation: Center for Marine Biotechnology and Biomedicine, Marine Biology Research Division, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Cao
authors.forename: Roger A
authors.initials: RA
authors.lastname: Chastain
authors.forename: Emiley A
authors.initials: EA
authors.lastname: Eloe
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Nogi
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Bartlett
mesh_terms: D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D006874:Hydrostatic Pressure; D008969:Molecular Sequence Data; D044130:Oceanospirillaceae / Q000145:classification* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D010802:Phylogeny; D011647:Puerto Rico; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S