| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥2,000,000 (Direct Cost: ¥2,000,000)
|
|---|
| Research Abstract |
Using 17 strains belonging to hyperthermophilic archaea, Thermococcdes (Pyrococcus furiosus, P. horikoshii, P. woesei, Thermococcus aggregans, T. celer, T. fumicolans, T. gorgonarius, T. guaymasensis, T. litoralis, T. pacificus, T. peptonophilus, T. profundus, T. stetteri, T. zilligii, T. waiotapuensis T. aegaeus, Palaeococcus ferrophilus) a correlation between biomembrane lipids and its phylogenetic classification. Although there were some differences in the growth optimum temperature for these strains, these were all cultivated at 80 C and the composition of cell lipids was compared. From a comparison of 16SrRNA, Thermococcales were classified into 3 groups, Pyrococcus, Thermococcus and Palaeococcus, but no significant difference was seen among their lipid compositions. The basic structure of those main lipids was consisted of caldarchaeol in which two biphytanyl chains (C40) were contained in a molecule. In the thermoacidophilic Sulfolobales, cyclopentane rings existed in the biphyt
… More
anyl chain of caldarchaeol, but no cyclopentane rings were found m the biphytanyl chains of 17 strains cultivated at 80 C. Furthermore, in the lipids of P.horikoshii, T.celer, T.guaymasensis and T.waiotapuensis, H type caldarchaeol possessing C80 hydrocarbon chain in which two biphytanyl chains were combined near the center in caldarchaeol was detected. However, the correlation of an existence of H type caldarchaeol with the phylogenetic classification were not seen. When compared with results of the thin layer chromatograms of polar lipids, the almost same pattern was shown. Also when ESI-MS of the total lipids of some strains was measured, the molecular ion peaks common to m/z894, and m/z1543 and m/z1786 were observed in negative ion mode. The molecular ion peak of m/z894 is equivalent to the combination of archaeol, one pentose or inositol, and phosphoric acid. And m/z1543 corresponds to the molecular ion peak shown in the combination of caldarchaeol, pentose or inositol, phosphoric acid. Moreover, m/z1786 is equivalent to the molecular ion peak in which one pentose or inositol, and phosphoric acid were combined with the molecule of m/z1543 The lipid equivalent to m/z1786, however, has not been detected from other archaea for the time being Consequently, these results indicate a possibility that the judgement whether the strain separated from high temperature area belongs to Thermococcales or not, can be done easily by the lipids analysis, because there is a characteristic feature in the lipid of Thermococcales which has not been found in other archaea. Less
|
