Kenichi Nakanishi

Mid-infrared spectroscopic measurement of ionic dissociative materials in the metabolic pathway.

We determine the pH dependency of the mid-infrared spectra in aqueous solution of the organic dissociative materials in the metabolic pathway: saccharide phosphates (G6P, F6P), adenosine, and its phosphates (ATP, ADP, AMP). The series of molar absorbance spectra for these reagents were obtained in a pH range of about 2 to 11 with a Fourier transform infrared (FT-IR) spectrometer equipped with a horizontal diamond attenuated total reflection (ATR) sampling accessory. We also provide a method of infrared spectral extraction of ionic dissociative materials by performing a linear least-square fitting utilizing the formulas of ionic dissociation equilibrium shift, and we obtain the infrared spectrum of each ionic species of the dissociative materials: G6P−, G6P2−; F6P−, F6P2−; ATP2−, ATP3−, ATP4−; ADP−, ADP2−, ADP3−; AMP, AMP−, AMP2−; and adenosine+, adenosine0. The infrared spectral structure of each ionic species of the dissociative materials in the metabolic pathway are discussed. Additionally, the possibility for a quantification system of the concentrations of the organic dissociative materials in varying pH is suggested.

Influences of Monosaccharides and its Glycosidic Linkage on Infrared Spectral Characteristics of Disaccharides in Aqueous Solutions

The infrared spectral characteristics of ten different types of disaccharides (trehalose, kojibiose, nigerose, maltose, isomaltose, trehalulose, sucrose, turanose, maltulose, and palatinose) and five different types of monosaccharides (glucose, mannose, galactose, talose, and fructose) in aqueous solutions (H2O and D2O) were determined. The infrared spectra were collected using the Fourier transform infrared attenuated total reflectance (FT-IR/ATR) method and comparisons between the degrees of absorption band-shift of the saccharide spectra in the H2O solution with those in the D2O solution with respect to the saccharide concentrations were done. The study revealed that the wavenumber shifts in the bands of mono- and disaccharides in the H2O and D2O solutions could be used as an indicator of the level of interaction between the saccharides and water. The study also focused on the glycosidic linkage position and the constituent monosaccharides and found that they have a significant influence on the infrared spectroscopic characterization of disaccharides in an aqueous solution.

Effects of sodium chloride on growth of ectomycorrhizal fungal isolates in culture

We studied the tolerance of ectomycorrhizal (ECM) fungi to sodium chloride (NaCl) to find the best fungus to aid growth of Pinus thunbergii. Four ECM fungi, Cenococcum geophilum, Pisolithus tinctorius, Rhizopogon rubescens, and Suillus luteus, were grown in liquid MMN media with five different concentrations of NaCl for 30 days, and their mycelial weights were determined. Mycelial weights of P. tinctorius and R. rubescens were not significantly different between 0 mM and 200 mM, whereas those of C. geophilum and S. luteus decreased with increasing NaCl concentration, indicating that the former two species were more tolerant to higher NaCl concentrations than the latter species. We further studied the intraspecific differences in NaCl tolerance of nine P. tinctorius isolates. They were grown on MMN agar media with six different concentrations of NaCl for 21 days, and their radial growth was measured. In total, the hyphal growth at 25 mM NaCl was significantly higher than those at the other NaCl concentrations, and EC50 values were confirmed at between 50 mM and 200 mM. Among the isolates, Pt03 and Pt21 showed measurable growth at 200 mM; the growth of Pt03 was not significantly different between 0 mM and 200 mM. The results indicate that there are intraspecific variations in NaCl tolerance of Pisolithus species.

Sugar metabolic analysis of suspensions of plant cells using an FT-IR/ATR method.

A simple, rapid and accurate evaluation of the sugar uptake rate of suspended plant cells from culture media was developed with the predicted sugar contents measured by mid‐infrared spectroscopy using a Fourier transform infrared (FT‐IR) spectrometer equipped with an attenuated total reflectance (ATR) accessory. We performed plant cell cultivation with Nicotiana tabacum cv. Bright Yellow No.2 (TBY‐2) in culture media, which had various combinations of glucose, fructose and sucrose concentrations at the initial stage, and measured simultaneously each sugar content in the medium by the FT‐IR/ATR method. By applying a logistic function to the predicted sugar contents and cell density in the medium during cultivation, the specific sugar uptake rates by the suspended TBY‐2 cells were easily and continuously obtained. Thus the kinetic sugar uptake phenomena by the TBY‐2 cells were well confirmed overall using the developed method. Additionally it was found that the fraction of sucrose of the initial total sugar content might kinetically affect the sugar uptake process and cell growth. Also, the relationship between the nondimensional cell density and sucrose content could be classified into three groups on the basis of the initial fraction of sucrose.

Mid-Infrared Spectroscopic Analysis of Sugar Metabolism by Rice Cells Suspending in Culture Medium

Abstract A simple, rapid and accurate method for analyzing sugar metabolic and alcohol production kinetics of suspension plant cells was developed by mid-infrared spectroscopy using a Fourier transform infrared spectrometer equipped with an attenuate total reflection accessory. Additionally the sugar metabolic kinetics was studied by focusing our attention on sugars as carbon sources in media at cultivation. Thus the relationship between the kinetic sugar uptake phenomena and alcohol production rate was well confirmed.

Water Sorption Analysis on Vegetables Using Modified Dubinin–Astakhov Parameters

Abstract The parameters of a modified Dubinin–Astakhov (DA) equation were studied for six kinds of fresh vegetables. The equilibrium moisture content data were fitted to the modified DA equation under the condition that the limit of the moisture content of the adsorption space represented by M 0 was assumed to be roughly equal to the equilibrium moisture content at the relative humidity of 97.3%. Then we calculated other two DA parameters of n and A e . The former is the distribution index of the Weibull probability density function, and the latter is a characteristic energy. In addition, the logarithm of the value increased proportionally with the increase of the n value, and the A e value could be experimentally identified by the degree of the pore inside the vegetable. Moreover, we discussed the relationship between the DA parameter M 0 and the moisture content M m calculated with the monolayer adsorption capacity defined by a Brunauer–Emmett–Teller equation. As the results, the logarithm of M 0 approximately represented the direct proportion to that of M m among all tested vegetables. This showed the power low relationship between M 0 and M m , and the slope of the line could mean the fractal dimension of the moisture sorption space.

Arbuscular mycorrhizas on Athyrium yokoscense and A. niponicum grown at a lead-contaminated site

To investigate the occurrence of arbuscular mycorrhizas (AM) and their morphological types, four Athyrium yokoscense and five A. niponicum individuals were collected at a lead-contaminated site. Three of the A. yokoscense and four of the A. niponicum formed AM structures. However, the percentage of AM formation within both species differed significantly among individuals. Morphological types of most AM structures were the Paris-type, except for one A. yokoscense that formed both Paris-type and Arum-type-like structures in different parts of the same root section. These results demonstrate that the two Athyrium species form AM associations in lead-contaminated soil.

Mid-Infrared Spectroscopic Monitoring of Enzyme Reaction Associating with Ionic Dissociative Metabolites

Abstract A simultaneous quantification method of concentrations of ionic dissociative materials and pH value in the mixture solutions was developed using the mid-infrared spectra of the ionic components extracted from the aqueous solutions. Additionally, we constructed an enzyme reactor accessory equipped with an FT-IR system for the continuous and non-destructive measurement and monitored the enzyme reaction process from glucose 6-phosphate to fructose 6-phosphate with D-glucose-6-phosphate ketol-isomerase. The developed quantification method was applied to the spectroscopic information of the reactant mixture, and the simulated time course of the reactant concentrations and pH value consistently represented the theoretical ones.

SU(3)L ⋊ (ℤ3 × ℤ3) GAUGE SYMMETRY AND TRI-BIMAXIMAL MIXING

We study an effective gauge theory whose gauge group is a semidirect product G = Gc ⋊ Γ with Gc and Γ being a connected Lie group and a finite group, respectively. The semidirect product is defined through a projective homomorphism (i.e. homomorphism up to the center of Gc) from Γ into Gc. To be specific, we take SU(3)L as Gc and ℤ3 × ℤ3 as Γ. We notice that the irreducible representations of the gauge group G necessarily contain three Gc-multiplets in spite of the Abelian nature of Γ = ℤ3 × ℤ3. This triplication phenomenon is due to the semidirect product structure of G. We suggest that the appearance of three families is attributable to this triplication. We give a toy model on the lepton mixing and show that under a particular vacuum alignment the tri-bimaximal mixing matrix is reproduced.

Spectroscopic Determination of Acid and Sugar Content in Fruit Juice

Abstract We conducted the fundamental studies to understand the ultraviolet (UV), visible (VIS), near-infrared (NIR), mid-infrared (MIR) and fluorescent spectroscopic characteristics of acid and sugar component in fruit juice. Satsuma mandarin (orange; Citrus unshu) juice obtained after reaming and filtration was used as the test fruit juice. In addition, we selected citric acid as the typical acid and fructose, glucose and sucrose as the important sugar components. Consequently, it was suggested that the modification of MIR spectroscopy or the NIR application based on the MIR spectroscopic analysis could contribute the acid and sugar quantification.