A5054834401- Geochemistry and Elemental Analysis
- Radioactive element chemistry and processing
- Chromium effects and bioremediation
- Mercury impact and mitigation studies
- Mine drainage and remediation techniques
- Aquatic Ecosystems and Phytoplankton Dynamics
- Microbial Community Ecology and Physiology
- Gas Sensing Nanomaterials and Sensors
- Wastewater Treatment and Nitrogen Removal
- Microbial bioremediation and biosurfactants
- Enzyme-mediated dye degradation
- Microbial Fuel Cells and Bioremediation
- ZnO doping and properties
- Marine and coastal ecosystems
- Biomedical and Chemical Research
- Enzyme Production and Characterization
- Analytical chemistry methods development
- Isotope Analysis in Ecology
- Heavy metals in environment
- Cassava research and cyanide
- Genomics and Phylogenetic Studies
- Biofuel production and bioconversion
- Microbial Metabolism and Applications
- Pharmaceutical and Antibiotic Environmental Impacts
- Fish Ecology and Management Studies
Akita Prefectural University
2014-2024
National Institute of Advanced Industrial Science and Technology
2023
Hokkaido University
2022
Fukui Prefectural University
2022
University of Tokyo Hospital
2019
The University of Tokyo
2015-2016
Tokyo University of Agriculture and Technology
2013-2014
University of Shizuoka
2000-2010
Institute for Environmental Sciences
1999-2010
National Institute for Environmental Studies
2004
An NAD(P)H-dependent Cr(VI) reductase (molecular weight = 65,000) was purified from a Cr(VI)-resistant bacterium, Pseudomonas ambigua G-1. Stoichiometric analysis of the enzymatic reaction showed that enzyme catalyzed reduction 1 mol to Cr(III) while consuming 3 NADH as an electron donor. Chromium(VI) reduced Cr(V) by one equivalent molecule in absence enzyme. Electron spin resonance species (g 1.979) formed during reduction. The amount about 10 times larger than nonezymatic These findings...
The crystal structures of biogenic Mn oxides produced by three fungal strains isolated from stream pebbles were determined using chemical analyses, XANES and EXAFS spectroscopy, powder X-ray diffraction. fungi-mediated oxidation aqueous Mn2+ produces layered analogous to vernadite, a natural nanostructured turbostratic variety birnessite. crystallites have domain dimensions ~10 nm in the layer plane (equivalent ~35 MnO6 octahedra), ~1.5-2.2 perpendicularly ~2-3 layers), on average. layers...
Properties of rf-sputtered molybdenum oxide films for electrochromic display devices have been investigated. This report mainly concerns the dependence properties on oxygen concentration in sputtering atmosphere. The were prepared by rf from a compressed powder MoO3 target under an operating pressure 4×10−2 Torr using mixture Ar-0.5–50% O2. Electrical resistivity formed increases with increasing atmosphere and ranges 2.5×1010 to ∼1×1012 Ω cm. Spectral transmittance is about 85% visible...
A Mn-depositing fungus, Acremonium-like hyphomycete strain KR21-2, was isolated from a Mn deposit occurring on the wall of storage bottle containing Mn(III, IV) oxide-coated streambed pebbles and stream water. 18S rRNA gene sequence analysis revealed that KR21-2 phylogenetically related to members order Hypocreales within class Ascomycetes. The spent culture medium at stationary phase fungal growth contained 54-kDa protein capable depositing oxides. enzymatic activity inhibited by azide...
In batch culture experiments we examined oxidation of As(III) and adsorption As(III/V) by biogenic manganese oxide formed a oxide-depositing fungus, strain KR21-2. We expected to gain insight into the applicability Mn-depositing microorganisms for biological treatment As-contaminated waters. cultures containing Mn2+ As(V), solid Mn phase was rich in bound (molar ratio, ∼30%) showed transiently high accumulation As(V) during early stage formation. As formation progressed, large proportion...
ABSTRACT Ascomycetes that can deposit Mn(III, IV) oxides are widespread in aquatic and soil environments, yet the mechanism(s) involved Mn oxide deposition remains unclear. A Mn(II)-oxidizing ascomycete, Acremonium sp. strain KR21-2, produced a phase with filamentous nanostructures. X-ray absorption near-edge structure (XANES) spectroscopy showed was primarily Mn(IV). We purified to homogeneity laccase-like enzyme Mn(II) oxidase activity from cultures of KR21-2. The oxidized yield suspended...
(2004). Sorption of Co(II), Ni(II), and Zn(II) on Biogenic Manganese Oxides Produced by a Mn-Oxidizing Fungus, Strain KR21-2. Journal Environmental Science Health, Part A: Vol. 39, No. 10, pp. 2641-2660.
We characterized the production of biogenic Mn oxides by four anamorphic ascomycete fungi isolated from streambed pebbles with oxide coatings. Based on 18S rRNA gene sequences, one strain was related to members order Xylariales and other three were within distinct lineages Pleosporales. These strains oxidized Mn(II) deposit when their growth approached stationary phase. The fungal showed X-ray diffraction patterns typical poorly crystalline vernadite (δ -MnO2), absorption near-edge structure...
The mechanism of uptake phenanthrene by Mycobacterium sp. strain RJGII-135, a polycyclic hydrocarbon-degrading bacterium, was examined with cultures grown on (induced for metabolism) and acetate (uninduced). Washed cells were suspended in aqueous solutions [9-(14)C]phenanthrene, then the collected filtration. Low-level steady-state (14)C concentrations uninduced achieved within first 15 s incubation. This immediate did not show saturation kinetics susceptible to inhibitors active transport,...
Transparent conducting films of cadmium‐tin oxide (CTO) were prepared by rf sputtering from a sintered target in an Ar or atmosphere. The electrical and optical properties the found to depend upon oxygen concentration gas mixture. with lowest resistivity high transmission 85% over visible region obtained without post‐heat‐treatment.
We propose a simple and precise measurement method for high-frequency dynamic displacement. It uses fiber optic interferometer with LiNbO3 phase modulator in the reference path. The of light is modulated triangle wave. By monitoring interference signal waveform, change difference displacement are measured without either complex calculation or complicated feedback system. proof-of-concept experiments show that waveforms relatively large amplitudes several tens nanometers distortion even when...