title: Reproduction and metabolism at - 10 degrees C of bacteria isolated from Siberian permafrost.
abstract: We report the isolation and properties of several species of bacteria from Siberian permafrost. Half of the isolates were spore-forming bacteria unable to grow or metabolize at subzero temperatures. Other Gram-positive isolates metabolized, but never exhibited any growth at - 10 degrees C. One Gram-negative isolate metabolized and grew at - 10 degrees C, with a measured doubling time of 39 days. Metabolic studies of several isolates suggested that as temperature decreased below + 4 degrees C, the partitioning of energy changes with much more energy being used for cell maintenance as the temperature decreases. In addition, cells grown at - 10 degrees C exhibited major morphological changes at the ultrastructural level.
authors.affiliation: Department of Earth Sciences, University of Southern California, 3651 Trousdale Parkway, Los Angeles, CA 90089-0740, USA.
authors.forename: Corien
authors.initials: C
authors.lastname: Bakermans
authors.forename: Alexandre I
authors.initials: AI
authors.lastname: Tsapin
authors.forename: Virginia
authors.initials: V
authors.lastname: Souza-Egipsy
authors.forename: David A
authors.initials: DA
authors.lastname: Gilichinsky
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Nealson
mesh_terms: D001419:Bacteria / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D004275:DNA, Ribosomal / Q000032:analysis; D005615:Freezing; D019015:Geologic Sediments / Q000382:microbiology*; D007202:Indicators and Reagents / Q000378:metabolism; D010078:Oxazines / Q000378:metabolism; D012492:Salts / Q000378:metabolism; D012800:Siberia; D012988:Soil Microbiology; D014966:Xanthenes
chemical_list: D004275:DNA, Ribosomal; D007202:Indicators and Reagents; D010078:Oxazines; D012492:Salts; D014966:Xanthenes; C005843:resazurin