自然環境下における生体鉱物化作用 : 温泉水およびバイオマットに生息する微生物が鉱物形成に及ぼす影響について

取得学位：博士(学術)，学位授与番号：博甲第691号，学位授与年月日：平成16年9月30日,学位授与年：200

Fe-Si biominerals in the Vilyuchinskie hot springs, Kamchatka Peninsula, Russia

The micromorphological structure of microbial mats (biomats) from the hot springs of the Vilyuchinskaya hydrothermal system, Kamchatka Peninsula, Russia, were investigated. The Vilyuchinskie hot springs had a discharge temperature of 55–56°C and Na-Ca-HCO3-type waters rich in silicic and boric acids. Water and biomats had high concentrations of Fe, Mn, Sr, and As. Enumeration of total bacterial abundance (TBA) demonstrated a low density of bacterial populations. However, the fractions of metabolically active bacteria and respiring iron-oxidizing bacteria in the hot-spring water were high, comprising 68 and 21% of TBA, respectively. Scanning electron microscopy equipped with an energy dispersive X-ray spectrometer (SEM-EDX) showed that unicellular rod-shaped bacteria about 5-μm long predominated in the brown biomats. The mineral capsules of these bacteria contained large amounts of Fe and Si. Extracellular and intracellular particles were observed by transmission electron microscopy. Fe-oxidizing bacteria were isolated from the biomats on agar plates with selective medium. Therefore, it can be concluded that microorganisms inhabiting the biomats of the Vilyuchinskie hot springs are essential for the deposition of Fe-minerals at neutral pH. [Int Microbiol 2004; 7(3):193–198

Chemical and microbiological investigations of hot spring deposits found at the hydrothermal systems of Kamchatka Peninsula, Russia

Graduate School of Natural Science and Technology, Kanazawa UniversityDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityInstitute of Volcanology of Far Eastern Division of Russian Academy of SciencesDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityChemical and biological characteristics of hot spring water, travertines and microbial mats collected from seven hydrothermal systems of the Kamchatka Peninsula, Russia are described. Water quality of the Vilyuchinskie hot springs was almost the same as those of Tazaki et al. (2003). Elemental concentration of hot spring waters was mainly composed of Na, K, Ca, and Mg with high contents of Fe, As, and Sr. The structure and elemental composition of travertine and biomats were studied with optical microscopy, ED-XRF, XRD, and EPMA. High content of As (43.88 wt%) was found in the deposits and biomats of the Nalychevskie hot springs. Extremely high concentration of Cd of 9.56 wt% was detected in the deposits of the Paratunskie hot springs. Traces of mercury (0.57 wt%) were found in the soft parts of biomats from the Apapelskie-1 hot springs. Optical microscopic observation of thin section of Oksinskie, Apapelskie, and Vilyuchinskie biomats revealed laminated structures. Soft parts of biomats mainly consist of cyanobacteria Anabaena spp. and green algae. A calcareous travertine of the Vilyuchinskie hot springs recorded the evidences of a long-term transition of water chemistry and periodic changes of environmental conditions such as water flux from the well and rainfall. Intensive hydrothermal alteration was observed in the Dachnye hot springs. Optical microscopic observation of microbial mats revealed diversity of microorganisms both in free-living forms and in association with mineral particles. Metabolically active cells were detected in the microbial mats indicating the impact of bacteria to the geochemical processes in the surroundings environments

Two pathways of proton transfer reaction to (triphos)Cu(η1-BH4) via a dihydrogen bond [triphos = 1,1,1-tris(diphenylphosphinomethyl)ethane]

The interaction of alcohols of variable strength with the copper(i) borohydride complex (triphos)Cu(η1-BH4) results in a great variety of DHB complexes which encompass different mechanisms involving M–H and E–H bond (E = B, O) activation steps

Heavy metallic concentration in microbial mats found at hydrothermal systems, Kamchatka, Russia

Department of Earth Sciences, Faculty of Science, Kanazawa UniversityInstitute of Volcanology Far Eastern Division of Russian Academy of SciencesDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityGraduate School of Natural Science and Technology, Kanazawa UniversityDepartment of Earth Sciences, Faculty of Science, Kanazawa UniversityThis study described the investigation of microbial mats that are rich in iron, arsenic, and manganese in four hydrothermal systems of Kamchatka, Russia namely Vilyuchinskie, Mutnovskie, Nachikinskie, and Malkinskie. The hydrothermal systems (hot springs) are contributing to the metallic and non-metallic mineral resources of Russia such as oil, gas, coal, copper, nickel, cobalt, tin, mercury, lead, zinc, diamond, platinum, gold, and silver. We observed the biogeochemical activities of microorganisms originating from microbial mats. The structure and elemental composition of microbial mats in these hydrothermal systems were studied with optical microscopy and scanning electron microscopy equipped with energy dispersive X-ray analyzer (EDX), whereas the water quality of these springs was measured by using pack tests. Additionally, portable Y-ray analyzer was employed to determine the kind and quantity of Y-ray in the atmospheric condition of sampling areas. Optical and scanning electron microscopic observations revealed that the microbial mats at these springs were mainly composed of a large number of microorganisms such as bacteria (coccus, bacillus, and filamentous), cyanobacteria, and algae in association with biominerals. Bacterial fluorometric enumeration of the thermal water informed that the total number of bacteria was relatively low, while the fraction of enzymatically active bacteria was high ranging from 27 % to 91 %. Besides that, ƒﾁ-ray observation showed that the predominantly ƒﾁ-ray range was between 320-380 keV dominating in green and black-colored microbial mats at Vilyuchinskie hot springs. Correspondingly, heavy metal and minerals deposits accumulated at all these springs indicating that microorganisms may contribute to binding and formation of the minerals. These activities and heavy mineral encrustation of cyanobacteria, bacteria, and algae may contribute to the growth of the heavy metal deposit (such as iron, manganese, and arsenic) at these springs. Obviously, Kamchatka hot springs provide a model for studying the potential role of prokaryotes and eukaryotes in the origin of heavy metal and minerals formation

Binuclear Copper(I) Borohydride Complex Containing Bridging Bis(diphenylphosphino) Methane Ligands: Polymorphic Structures of [(µ2-dppm)2Cu2(η2-BH4)2] Dichloromethane Solvate

Bis(diphenylphosphino)methane copper(I) tetrahydroborate was synthesized by ligands exchange in bis(triphenylphosphine) copper(I) tetrahydroborate, and characterized by XRD, FTIR, NMR spectroscopy. According to XRD the title compound has dimeric structure, [(μ2-dppm)2Cu2(η2-BH4)2], and crystallizes as CH2Cl2 solvate in two polymorphic forms (orthorhombic, 1, and monoclinic, 2) The details of molecular geometry and the crystal-packing pattern in polymorphs were studied. The rare Twisted Boat-Boat conformation of the core Cu2P4C2 cycle in 1 is found being more stable than Boat-Boat conformation in 2