title: Solute accumulation in the deep-sea bacterium Photobacterium profundum.
abstract: The identity and amounts of intracellular solutes in the deep-sea bacterium Photobacterium profundum strain SS9 were studied using nuclear magnetic resonance techniques. P. profundum strain SS9, a moderate piezophile which grows optimally at 20-30 MPa primarily accumulated glutamate and betaine, with lesser amounts of alanine, beta-hydroxybutyrate (beta-HB) and oligomers composed of the beta-HB units when grown at 0.1 MPa to early stationary phase. When grown at the optimal pressure, the cells preferentially increased intracellular concentrations of beta-HB and beta-HB oligomers, while the amino acid pools remained relatively constant. Since the organic solutes increased with increasing external NaCl in the medium, they are functioning as osmolytes. The beta-HB molecules represent a novel class of osmolytes, termed 'piezolytes,' whose cellular levels responded to hydrostatic pressure as well as osmotic pressure. Factors such as cell growth stage and temperature were also examined for their effect on the solute distribution in these cells.
authors.affiliation: Merkert Chemistry Center, Boston College, Chestnut Hill, MA, USA.
authors.forename: Deana Desmarais
authors.initials: DD
authors.lastname: Martin
authors.forename: Douglas H
authors.initials: DH
authors.lastname: Bartlett
authors.forename: Mary F
authors.initials: MF
authors.lastname: Roberts
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D000222:Adaptation, Physiological; D000409:Alanine / Q000378:metabolism*; D001622:Betaine / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D018698:Glutamic Acid / Q000378:metabolism*; D006874:Hydrostatic Pressure; D007424:Intracellular Fluid / Q000737:chemistry; D008954:Models, Biological; D019906:Nuclear Magnetic Resonance, Biomolecular; D010776:Photobacterium / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D013696:Temperature; D014871:Water Microbiology; D014882:Water-Electrolyte Balance
chemical_list: D012462:Saline Solution, Hypertonic; D018698:Glutamic Acid; D001622:Betaine; D000409:Alanine; D020155:3-Hydroxybutyric Acid