title: Antarctic ice core samples: culturable bacterial diversity.
abstract: Culturable bacterial abundance at 11 different depths of a 50.26 m ice core from the Tallaksenvarden Nunatak, Antarctica, varied from 0.02 to 5.8 × 10(3) CFU ml(-1) of the melt water. A total of 138 bacterial strains were recovered from the 11 different depths of the ice core. Based on 16S rRNA gene sequence analyses, the 138 isolates could be categorized into 25 phylotypes belonging to phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. All isolates had 16S rRNA sequences similar to previously determined sequences (97.2-100%). No correlation was observed in the distribution of the isolates at the various depths either at the phylum, genus or species level. The 25 phylotypes varied in growth temperature range, tolerance to NaCl, growth pH range and ability to produce eight different extracellular enzymes at either 4 or 18 °C. Iso-, anteiso-, unsaturated and saturated fatty acids together constituted a significant proportion of the total fatty acid composition.
authors.affiliation: Center for Cellular and Molecular Biology, Hyderabad 500 007, India. shivas@ccmb.res.in
authors.forename: Sisinthy
authors.initials: S
authors.lastname: Shivaji
authors.forename: Zareena
authors.initials: Z
authors.lastname: Begum
authors.forename: Singireesu Soma
authors.initials: SS
authors.lastname: Shiva Nageswara Rao
authors.forename: Puram V
authors.initials: PV
authors.lastname: Vishnu Vardhan Reddy
authors.forename: Poorna
authors.initials: P
authors.lastname: Manasa
authors.forename: Buddi
authors.initials: B
authors.lastname: Sailaja
authors.forename: Mambatta S
authors.initials: MS
authors.lastname: Prathiba
authors.forename: Meloth
authors.initials: M
authors.lastname: Thamban
authors.forename: Kottekkatu P
authors.initials: KP
authors.lastname: Krishnan
authors.forename: Shiv M
authors.initials: SM
authors.lastname: Singh
authors.forename: Tanuku N R
authors.initials: TN
authors.lastname: Srinivas
mesh_terms: D000222:Adaptation, Physiological; D000864:Antarctic Regions; D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D058491:Bacterial Load; D044822:Biodiversity; D004798:Enzymes / Q000378:metabolism; D005227:Fatty Acids; D005615:Freezing; D007053:Ice / Q000032:analysis*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology
chemical_list: D004798:Enzymes; D005227:Fatty Acids; D007053:Ice; D012336:RNA, Ribosomal, 16S