title: The bacteria and bacteriophages from a Mesquite Flats site of the Death Valley desert.
abstract: Arid zones cover over 30 % of the Earth's continental surface. In order to better understand the role of microbes in this type of harsh environment, we isolated and characterized the bacteriophages from samples of the surface sand of the Mesquite Flats region via electron microscopy and DNA sequencing of a select number of cloned phage DNAs. An electron microscopic analysis of the recovered virus-like particles revealed at least 11 apparently different morphotypes sharing structural characteristics of the Caudoviridae family of tailed phages. We found that 36 % of the sequences contained no significant identity (e-value >10(-3)) with sequences in the databases. Pilot sequencing of cloned 16S rRNA genes identified Bacteroidetes and Proteobacteria as the major bacterial groups present in this severe environment. The majority of the 16S rDNA sequences from the total (uncultured) bacterial population displayed ≤96 % identity to 16S rRNA genes in the database, suggesting an unexplored bacterial population likely adapted to a desert environment. In addition, we also isolated and identified 38 cultivable bacterial strains, the majority of which belonged to the genus Bacillus. Mitomycin-C treatment of the cultivable bacteria demonstrated that the vast majority (84 %) contained at least one SOS-inducible prophage.
authors.affiliation: Laboratoire de Génomique et Biodiversité Microbienne des Biofilms, Institut de Génétique et Microbiologie; CNRS UMR 8621, Univ Paris-Sud, Bâtiment 409, 91405, Orsay, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Prestel
authors.forename: Christophe
authors.initials: C
authors.lastname: Regeard
authors.forename: Sylvie
authors.initials: S
authors.lastname: Salamitou
authors.forename: Julie
authors.initials: J
authors.lastname: Neveu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Dubow
mesh_terms: D001407:Bacillus / Q000145:classification / Q000302:isolation & purification / Q000821:virology; D041963:Bacteroidetes / Q000145:classification / Q000302:isolation & purification / Q000821:virology; D001483:Base Sequence; D044822:Biodiversity; D002140:California; D017899:Caudovirales / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D003889:Desert Climate; D021141:Nucleic Acid Amplification Techniques; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification / Q000302:isolation & purification / Q000821:virology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014481:United States
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral; D012336:RNA, Ribosomal, 16S