Ether lipid is one of the most distictive markers that discriminate Archaea and Bacteria. Among Archaea, there are diversity in their core lipid structure, phosphate-containing polar-head groups, and glycolipid-sugar moieties. For example, non-methaogenic thermophilic Archaea contain mainly tetraether type core and inositol as a sole phosphate-containing polar-head group, lipids of extreme halophiles are composed of only diether type core lipid and glycerophosphate and its derivatives as polar head groups, and all methanogens so far analyzed are characterized by the presence of nitrogen-containing polar groups. The diversity of lipids in Archaea is not random but is determined by a phylognetic relationship. Therefore qualitative lipid composition is used as a chemotaxonomic marker of extreme halophiles and methanogens. The most fundamental phenotypic marker that distinguishes Archaea and Bacteria, which is the highest taxonomic rank of living organisms, is the enantiomeric difference of glycerophosphate backbone structure of their polar lipids. It could be assumed that this difference has been kept since the time when organisms of the two domains had been differentiated.

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The lipids of the archaebacteria grown at a normal temperature is fundamentally the archaeol in which sn-2 and sn-3 of the glycerol are ether linked with the phytanol of C₂₀, but those of the bacteria grown at high temperature are mainly the caldarchaeol with the structure in which the archaeol of two molecules confronts each hydrocarbon and methyl terminals of hydrocarbon chains are linked.
The thermophilic archaea can be separated into two types, i.e., those living in a strong acidic condition and others living around neutral condition, and also, the former consists of tetraether-type lipids without exception. In the bacteria growing in a neutral condition, however, not only the tetraether-type lipids, but also some of those being composed of the diether-type lipids as their main lipids have been detected.
Main lipids of the archaea belonging to family Sulfolobaceae possess the calditocaldarchaeol as a core lipid, which formed by substituting the glycerol of the one side of the caldarchaeol with the calditol and it seems highly probable that such characteristic structure is contributed to the acid resistance and the thermostability of these archaebacteria.
In addition, it became clear that the polar heads containing phosphorus in lipids of the thermophilic archaea consist of the negative electric charge components such as inositol phosphate.

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Archaebacterial membrane lipids are mainly ether-linked lipids in place of the usual membrane ester-linked phospholipids of eubacteria and eukaryotes and enable the organisms to inhabit extreame environments. These lipids are composed of a glycerol group and saturated isoprenoid moieties with 20 or 40 carbon atoms. It is proposed that geranylgeranyl diphosphate, which is synthesized by a cytosolic geranylgeranyl diphosphate synthase or geranylgeranyl phosphate kinase, is attached to glyceryl phosphate, followed by saturation of the geranylgeranyl moieties to make phytanyl group and head-to-head dimerization to produce C₄₀ etherlinked lipids.
The gene of geranylgeranyl diphosphate synthase in Sulfolobus acidocaldarius was isolated by the method of red-white screening system.
Compared with other genes of isoprenyl diphosphate synthase, some discussion of evolution was made.

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Recently, so many genome analysis programs of the microorganisms have been investigating in the world, and some of them (5 strains) have finished and opened the sequencing data on computer net-work. From these results, we realyzed that the genome size of microorganisms and the quantity of regulatory functional genes and pseudo genes were corresponding. For example, 134 regulatory genes were identified in Synechocystis sp. PCC 6803 (3.6 Mb), however only 7 regulatory genes in Methanococcus Jannaschii (1.7 Mb). We believe that such difference of the genome size is corresponded to the quantity of the environmental stresses. Thus, this is very important to study the smaller genome organisms like hyperthermophilic archaea to realize the minimum genome for organisms. In my country, the genome project of new hyperthermophilic archaeon, Pyrococcus horikoshii, is in progress. P. horikoshii showed obligately barophilic growth profile at maximum high temperature (103°C), thus we may expect that the barophily of the deep-sea hyperthermophiles will be more understandable to consider about the origin of life and its evolution from the its genomic results.

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Phylogenetic tree based on 16S rRNA or protein sequences shows that all known organisms are related suggesting a common ancestor. All organisms are divided into three groups, eukarya, bacteria, and archaea. Most proteins produced in archaea have eukaryotic features, which indicate close relationship of archaea and eukarya in the course of evolution. Especially, hyperthermophilic archaea are considered to evolve most slowly in archaea domain remaining ancestral features of higher eukaryotes. Pyrococcus sp. KOD 1 is a newly isolated hyperthermophilic archaeon from a solfatara at a wharf of Kodakara Island, Kagoshima Japan. The optimum temperature for KOD 1 cell growth is 95°C. Unusual enzyme characteristics on KOD 1 protease, amylase, DNA polymerase, glutamate synthase, Rec protein, aspartyl tRNA synthetase and molecular chaperonin are discussed. Some applications using KOD 1 enzymes are also introduced, e.g. rapid PCR by KOD 1 DNA polymerase and in vitro stabilization and in vivo solubilization of foreign proteins by KOD 1 chaperonin.

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Molecular mechanisms of unusual heat stability of proteins, enzymes, DNAs, tRNAs, and membrane lipids of thermophiles, both eubacterial and archaebacterial thermophiles are briefly reviewed.

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Archaebacterial lipids are featured by C_20^-, C_25^-and C_40^-polyisoprenoid chains connected to a glycerol moiety by an ether linkage. The polyisoprenoid lipids including model compounds gave rise to double layer, unilayer and Q phase-like membranes. The morphology depended strongly on the structure of the lipids. The liposomal membranes made of the polyisoprenoid lipids were very stable at high temperature without undergoing morphological perturbation. The membranes were highly resistant to permeation of protons and various organic compounds as well as inorganic salts. It was also found that the surface energy of the molecular assemblies were extraordinally low, some approaching to the value of fluorocabon materials. These properties and functions were explained by fluidity of each polyisoprenoid chain and rigidity of an polyisoprenoid chain-array in the membranes.

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Thermal properties of smectic liquid crystals of dimyristoylphosphatidylglycerol sodium salt (DMPG) in water were investigated as a function of temperature above the gel-liquid crystal transition temperature, T_m, by X-ray diffraction analysis of the repeat distance of the bilayer, differential scanning calorimetry (DSC) for phase transition, the hyperfine splitting constant in electron spin resonance (ESR) method with spin probes and equilibrium spreading pressure. The data obtained were found to differ remarkably below and above the critical temperature T^* (=31.7°C) for DMPG bilayers. The weakening of hydration of terminal glycerol moiety in DMPG at T^*, with consequently enhanced microflexibility of DMPG bilayers above this temperature may be explanation for these differences. The effects of dehydration of the terminal glycerol moiety on surface activity was confirmed from the temperature dependence of equilibrium spreading pressure of DMPG.

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Micelle formation and adsorption at air/water interface were investigated as function of temperature for aqueous solutions of the nonionic surfactant, n-nonyl-β-D-thiomaltoside (NTM), used as a membrane-protein solubilizer by surface tension measurements (drop volume method). For comparison with NTM, such surface tension measurements were performed even for aqueous solutions of decanoyl-N-methylglucamide (MEGA-10). Examination was also made of the effect of adding alcohols (methanol, ethanol and 1-butanol) on critical micellization concentration (cmc) and on surface activity. As for the behavior of surface activity as well as cmc, NTM was found more similar to ionic surfactants than typical nonionic surfactants such as poly oxy ethylene alkyl ethers ; NTM exhibited no cloud point at least up to 100°C, but showed a minimum cmc at 28.3°C in the curve of temperature vs. cmc. Light scattering measurement at 25°C (the Debye plot) gave a comparatively small aggregation number of 16.4, indicating that the present thermodynamic analysis based on the phase separation model (PSM) may involve a rough approximation. However, a thermodynamical feature of NTM may be understood from PSM and facilitates comparison with MEGA-10 and alkyl glucosides.
In addition, the hydrophilic-lipophilic balance (H.L.B.) value not indicated by Davies was determined for sulfur in amphiphilic organic compounds (-S-) as 1.5.

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Examination was made of the effects of surfactants and builders on the decoloration of Orange II and transfer of Orange II to nylon in the presence of horseradish peroxidase (HRP) and hydrogen peroxide at pH 9.0 and 20°C. The decoloration rate constant of Orange II decreased with increase in anionic and nonionic surfactant. The decoloration rate decreased 70% in the presence of Triton X-100. Inhibition of the transfer of Orange II to nylon was markedly af-fected by the presence of anionic surfactant (SDS). The decoloration rate constant and transfer of dissolved Orange II to nylon fabric were not affected by the builder. The transfer of Orange II to nylon fabric was also examined in the presence of HRP and detergent, containing SDS and the builder. Orange II was rapidly destroyed, and consequently there was no transfer of Orange II to nylon fabric. This transfer did occur on using a different detergent, containing Triton X-100 and the builder. SDS with HRP is thus shown to effectively inhibit dye transfer.

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The kinetics of the aerobic oxidation of phosphatidylethanolamine (PE) induced by copper (II) ions was studied in Tween 20 micelles at 37°C. The kinetic order with respect to concentrations of PE hydroperoxides was 0.3, indicating the oxidation to be initiated by decomposition of the hydroperoxides catalyzed by copper (II) ions. The copper (II) ion-induced oxidation of PE+phosphatidylcholine (PC) in Tween 20 micelles was carried out, and the oxidation rate was noted to increase with the PE/PC mole ratio, possibly due to formation of a PE-copper (II) ion complex.

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Examination was made of acylation reactions of (+) -2-pinene (1), (-) -2 (10) -pinene (2) and (+) -1-p-menthene (3) with acid anhydrides (acetic anhydride and propionic anhydride) in the presence of synthetic zeolites and the following results were obtained. With US-Y type zeolites, (4) (13) were obtained from (1) (3) as the main products, respectively and evaluated on the basis of odor ; (9) emitted odors that would qualify them as flavor agents. The antimicrobial activity of acylated compounds (4) (13) toward Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Aspergillus niger and Penicillium citrinum was also examined and it was found that compound (7) (at 100 μg/mL) derived from (1) and (2), completely inhibited the growth of B. subtilis.

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The queen substance [(E) -9-oxo-2-decenoic acid] 1 is a pheromone secreted by the queen honeybee (Apis mellifera) and inhibits ovary development in worker bees and queen rearing within the colony. In consideration of its biological importance, various routes for its synthesis have been published. The synthesis of 1 from methyl 3-formylpropionate 2 is reported here for the first time.
Keto-ester 4, prepared from 2 and 2-methyl-2-vinyl-1, 3-dioxolane 3 by radical addition reaction in 76% yield, was treated with hydrazine monohydrate in the presence of potassium hydroxide in diethylene glycol to give ethylenedioxy carboxylic acid 5 in 68% yield. The reduction of 5 with sodium bis (2-methoxyethoxy) aluminum hydride in benzene under reflux gave acetal alcohol 6 in 75% yield, which was then oxidized to acetal aldehyde 7 with pyridinium chlorochromate in 76% yield. Acetal aldehyde 7 was condenced with malonic acid to give 8 in 71% yield. The hydrolysis of 8 was carried out with 1 M hydrochloric acid to give 1 in 92% yield.

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