Large scale collection and their industrial application of hyperthemophilic archaeal genome from deep sea hydrothermal envirenments

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In this study, we first investigated the deep sea hydrothermal vent environments and its microbial community. Then we collected the large scale genome information of hyperthermophilic microrganisms distributed in those hot vents and tried to develop their genetic resources to industrial application of hyperthermophilies.(1) To determine whether the geochemical process (boiling/distillation) of subseafloor hydrothermal fluids affects the formation of microbial communities, we examined the microbial communities at three different vent sites located within a few tens meters of one another in the Iheya North field. In addition to chimney structures, colonization devices capturing subseafloor communities entrained by the vent fluids were studied, using culture-dependent and-independent methods. Microbial analyses demonstrated the occurrence of distinctive microbial communities in each of the hydrothermal niches. Within a chimney structure, there was a transition from a mixed community of me … More w/Miles and thermophiles in the exterior parts to thermophiles in the interior In comparison to gas-depleted and normal fluid% gas-enriched fluids harbored more abundant chemolithoautotrophs with gaseous component-dependent energy metabolism, such as hydrogenotrophic methanogenesis. Subseafloor phase-separation and -segregation may play a key role in supplying energy and carbon sources to vent-associated chemolithoautotrophs and subvent microbial communities.(2) In the Iheya North field in the Mid-Okinawa Dough we studied the spatial distribution, diversity and physiological characteristics of the epsilon-Proteobacteria in various microbial habitats in the vicinity of this deep-sea hydrothermal vent The 111 gill samples were predominantly colonized by epsilon-Proteobacteria Energy metabolism of epsilon-Proteobacteria isolates was highly versatile. Tree topology generated from the metabolic traits was significantly different from that of 16S rRNA tree. Culturability of epsilon-Proteobacteria in various microbial habitats differed among the phylogenetic subgroups. Members of Sulfurimonas were characterized by the robust culturability, and the other phylogenetic subgroups appeared to lose culturability in seawater, probably because of the sensitivity to oxygen. These results provide new insight into the ecophysiological characteristics of the deep-sea hydrothermal vent epsilon-Proteobacteria, which has never been assessed by comparative analysis of the 16S rRNA genes.3) Over 50 introns have been reported in archaeal rRNA genes (rDNAs), a subset of which nests putative homing endonuclease genes. We studied the identification and characterization of a novel archaeal LAGLIDADG-type homing endonuclease, I-ApeI, encoded by the ApeK1.S908 intron within the 16S rDNA of Aeropyrum pernix K1. I-ApeI consisits of 222 amino acids and harbors two LAGLIDADG-like sequences. It recognizes the 20 bp non-palindromic sequence 5'-GCAAGGCTGAAAC ↓ TTAAAGG and cleaves target DNA to produce protruding tetranucleotide 3' ends. Either Mn^<2+> or Co^<2+> can be substitude for Mg^<2+> as a cofactor in the cleavage reaction. Of the 20 bases within the minimal recognition site, 7 are essential for cleavage and are located at positions proximal to the cleavage sites. Less