Fatty acid and DNA analyses of Permian bacteria isolated from ancient salt crystals reveal differences with their modern relatives
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The isolation of living microorganisms from primary 250-million-year-old (MYA) salt crystals has been questioned by several researchers. The most intense discussion has arisen from questions about the texture and age of the crystals used, the ability of organisms to survive 250 million years when exposed to environmental factors such as radiation and the close similarity between 16S rRNA sequences in the Permian and modern microbes. The data in this manuscript are not meant to provide support for the antiquity of the isolated bacterial strains. Rather, the data presents several comparisons between the Permian microbes and other isolates to which they appear related. The analyses include whole cell fatty acid profiling, DNA–DNA hybridizations, ribotyping, and random amplified polymorphic DNA amplification (RAPD). These data show that the Permian strains, studied here, differ significantly from their more modern relatives. These differences are accumulating in both phenotypic and molecular areas of the cells. At the fatty acid level the differences are approaching but have not reached separate species status. At the molecular level the variation appears to be distributed across the genome and within the gene regions flanking the highly conserved 16S rRNA itself. The data show that these bacteria are not identical and help to rule out questions of contamination by putatively modern strains.
KeywordsPermian bacteria Halotolerant Salt Halophilic Ribotyping
This research has been supported by the US National Science Foundation (EAR-0085371 and EAR-9714203) and by DuPont Qualicon Inc. We thank Heather Maughan for providing the RAPD gels.
- Heyndrickx M, Lebbe L, Kersters K, DeVos P, Forsyth G, Logan NA (1998) Virgibacillus a new genus to accommodate Bacillus pantothenticus (Proom and Knight 1950). Emended description of Virgibacillus pantothenticus. Int J Syst Bacteriol 48:99–106Google Scholar
- Johnson JL (1994) Similarity analysis of DNAs. In: Gerhardt P, Murray RGE, Wood WA, Krieg NR (eds) Methods for general and molecular bacteriology. American Society for Microbiology, Washington DC, pp 655–681Google Scholar
- Marmur J (1961) A procedure for the isolation of deoxyribonucleic acid from microorganisms. J Mol Biol 3:208–219Google Scholar
- Maughan H, Birky CW Jr, Nicholson WL, Rosenzweig WD, Vreeland RH (2002) The paradox of the “ancient” bacterium which contains “modern” protein-coding genes. J Mol Biol Evol 19:1637–1639Google Scholar
- Owen RJ, Hill LR (1979) The estimation of base compositions, base pairing, and genome size of bacterial deoxyribonucleic acids. In: Skinner FA, Lovelock DW (eds) Identification methods for microbiologists. Academic Press, London, pp 217–296Google Scholar
- Parkes RJ, Cragg BA, Wellsbury P (2000) Recent studies on bacterial populations and processes in subseafloor sediments: a review. Hydrogeology 8:11–28Google Scholar
- Priest F, Austin B (1986) Modern bacterial taxonomy. Chapman & Hall, London, pp 111–134Google Scholar
- Rocap G, Larimer FW, Lamerdin J, Malfatti S, Chain P, Ahlgren NA, Arellano A, Coleman M, Hauser L, Hess WR, Johnson ZI, Land M, Lindell D, Post AF, Regala W, Shah M, Shaw SL, Steglich C, Sullivan MB, Ting CS, Tolonen A, Webb EA, Zinser ER, Chisholm SW (2003) Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation. Nature 424:1042–1047CrossRefPubMedGoogle Scholar