HR: 0800h
AN: V41B-1368    [Abstracts]
TI: Genomics approach to the environmental community of microorganisms
AU: * kawarabayasi, y
EM: kawarabayasi.yutaka@nifty.com
AF: National Institute of Advanced Industrial science and Technology, Higashi 1-1, Tsukuba, 305-8566 Japan
AU: maruyama, a
EM: maruyama-aki@aist.go.jp
AF: National Institute of Advanced Industrial science and Technology, Higashi 1-1, Tsukuba, 305-8566 Japan
AB: It was indicated by microscopic observation or comparison of 16S rDNA sequence that many extremophiles were surviving in many hydrothermal environments. But it is generally said that over 99% of total microbes are now uncultivable. Thus, we planned to identify uncultivable microbes through direct sequencing of environmental DNA. At first, shotgun plasmid libraries were directly constructed with the DNA molecules prepared from mixed microbes collected from low-temperature hydrothermal water at RM24 in the Southern East Pacific Rise (S-EPR). It was shown that the sequences of some number of clones indicated the similar feature to the intron in eukaryote or tandem repetitive sequence identified in some human familiar diseases. The results indicated that many microorganisms with eukaryotic feature were dominant in low temperature water of S-EPR. Secondly, shotgun plasmid libraries were constructed from the environmental DNA prepared from Beppu hot springs. The ORFs were easily identified all clones determined entire sequence. Thus it can be said that hot springs is good resources for searching novel genes. At last, the mixed microbes isolated from Suiyo seamount were used for construction of shotgun library. The clones in this library contained the ORFs. From some clones in hot spring and Suiyo sample, aminoacyl-tRNA synthatase, which is generally present in all organisms, was isolated by similarity. The phylogenetic analysis of aminoacyl-tRNA synthetase identified indicated that novel and unidentified microorganisms should be present in hot spring or Suiyo seamount. The novel genes identified from Suiyo seamount were also utilized for expression in E. coli. Some gene products were successfully obtained from the E. coli cells as soluble proteins. Some protein indicated the thermostability up to 70_E#8249;C, meaning that the original host cell of this gene should be stable up to the same temperature. Our work indicates that environmental genomics, including the direct cloning, sequencing of environmental DNA and expression of gene identified, is powerful approach to collect novel uncultivable microbes or novel active genes.
DE: 1615 Biogeochemical processes (4805)
DE: 0400 Biogeosciences
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting