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Effects of cyclic oligosaccharide cyclodextrin (CD) on stability and conformation of lysozyme were clarified thermodynamically and rheologically by DSC, viscosity, and circular dichroism measurements. The modified β-CD relatively destabilized the folded state of lysozyme by stabilizing the unfolded state due to inclusion of hydrophobic part into the hydrophobic interior of CD. The order of higher destabilization effect was acetyl-β-CD > methyl-β-CD > hydroxypropyl-β-CD. Apparent number of bound CD to unfolded state for methyl-, hydroxypropyl-, and acetyl-β-CD is 6.7 ± 0.7, 4.2 ± 1.1, and 18.6 ± 4.3 and the binding constant is 5.5 ± 0.8, 6.7 ± 2.4, and 4.4 ± 1.2 L mol −1 , respectively. The viscosity for unfolded state was increased with an increase in the each modified β-CD concentration, suggesting that the inclusion of CD on a part of hydrophobic core at unfolded state leads to break the hydrophobic core, then lysozyme would be more spread structure. The substituent of CD can accelerate instability by directly breaking hydrogen bond and/or can restrain instability by increase in hydrophobic interaction. The fact that the each modified CDs has different destabilization effect shows a possibility to control the stability of protein by the substitution of CD.

Nine species of basidiomycota and one species of ascomycota were grown in an ammonium sulphate media and on beech wood; and the general (15)N dynamic patterns of the hyphae were examined. The fungal body initially became depleted in (15)N in both the types of incubation. However, the underlying mechanisms were quite different, that is, significant fungal (15)N drop on the beech wood is associated with the fungal N reallocation and the uptake of atmospheric ammonia and/or NO(x), in addition to isotope fractionation during assimilation. Although the (15)N values of the wood-decomposing basidiocarps were generally close to the (15)N values of the wood, it does not always indicate that the wood derived N was the sole N source for the fungi throughout the growth periods as shown in our wood-decomposing experiment.

Factors that affect the δ13C values of fungi need to be analyzed for the progress of isotope-based studies of food-chain or organic matter dynamics in soils. To analyze the factors that control δ13C values of the fungal body, basidiomycete and ascomycete species were grown on a beechwood substrate (six species) and in glucose medium (nine species), and the δ13C value of produced fungal body was compared to that of the carbon source. The 13C enrichment (Δδ13C) in the fungal aggregates compared to the decomposed wood varied from 1.2 to 6.3‰ among six species. In the glucose substrate experiment, the degree of 13C enrichment in the hyphal mat was relatively small and varied from −0.1 to 2.8‰ among nine basidiomycetes species depending on their growth stage. Calculated δ13C values of the respired CO2 were lower than those of the hyphal mat, organic metabolites and the glucose used. The degree of 13C enrichment was affected by fungal species, substrate and growth stage. Fungal internal metabolic processes are the plausible mechanism for the observed isotopic discrimination between fungal bodies and substrates. Especially, dark fixation of ambient CO2 and kinetic isotope fractionation during assimilation and dissimilation reactions could well explain Δδ13C dynamics in our experiments. Through the analysis of field Δδ13C, we could know undisturbed fungal status about starvation, aeration and type of decomposition.

A molecular technique for the identification of the Gigaspora margarita isolate CK based on the detection of a DNA sequence of 235 bp as its diagnostic marker was evaluated to investigate the survival and establishment of introduced arbuscular mycorrizal fungi (AMF) in a field ecosystem. In March 2001, roots and rhizosphere soil of Eragrostis curvula and Miscanthus sinensis were collected from the Mizunashi River at Mt. Fugendake (Nagasaki Prefecture, Japan), where plant seeds and AMF including G. margarita CK had been introduced for reforestation after the occurrence of repeated pyroclastic flows. We detected the marker sequence from DNA preparations of E. curvula roots and Gigaspora spores in the rhizosphere. This clearly showed that the isolate occurred at both hyphal and sporal stages. It was shown that the isolate survived and developed a life cycle in the revegetation area for 4 years. It was confirmed that the method was effective for tracing the isolate in samples collected from field ecosystems.

Six-month-old seedlings of Quercus serrata and Quercus glauca in a nursery were inoculated with the ectomycorrhizal fungus Laccaria amethystea encapsulated in alginate gel and grown in the nursery. The seedlings were collected at 1, 3, and 5 months after the inoculation and examined for colonization of the root system with ectomycorrhizal fungi. The roots within 5 months after the inoculation showed rudimentary ectomycorrhizal colonization. The level of colonization of the root system was estimated based on the intensity of hyphal covering on the root tips by staining with a fluorescent dye and expressed as an index of mycorrhizal colonization (IMC). IMC increased with the time after inoculation and reached values of 4 and 12% in Q. serrata and Q. glauca, respectively at 5 months after the inoculation. The determination of IMC may enable to assess the development of mycorrhizal colonization of the root system that shows rudimentary ectomycorrhizas after the inoculation.

An aerosol observation campaign was conducted at the summit of Mt. Fuji (at an altitude of 3776 m), which is located 170 km northwest of Miyakejima. Individual aerosol particles were collected with an electrostatic aerosol sampler and the number–size distribution and composition were examined by electron microscopy. Number–size distributions were measured with the combination of a diffusion battery (DB) and a condensation particle counter. Sulfate and sulfur dioxide concentrations were also determined. During the first half of the campaign (13–15 September 2000), high number fractions of sulfuric-acid containing particles with a mode radius around 0.06 μm were observed in the radius range of 0.02–0.2 μm coincident with a humid maritime air mass originated from the south. Sulfate and sulfur dioxide also showed high concentrations in this period. These results suggested that the volcanic plumes of Miyakejima were transported up to the summit of Mt. Fuji. Number–size distributions determined by electron microscope were consistent with those derived using the DB. During the later half of the experiment (18–20 September), low fractions of sulfuric-acid containing particles represented only a small fraction of the total particle number, coincident with a dry continental air mass originating from the west.

To investigate the auto-ecology of a strain of Gigaspora margarita in a commercial inoculum, we found a pair of PCR primers amplifying a sequence of 235 bp diagnostic of the isolate. We designed an oligonucleotide probe based on the DNA sequence. The combination of PCR and the probing successfully detected the diagnostic sequence from both DNA preparations of single spores and colonized roots. This protocol enabled us to distinguish the isolate among several isolates from Japan, Nepal and the USA.

The 15N natural abundance in Pinus densiflora Sieb. et Zucco that had been inoculated and not inoculated with ectomycorrhizal fungi (Suillus granulatus (L.:Fr.) O. Kuntze) was compared. The inoculated pine needles showed a lower δ15N value, while the uninoculated ones showed a higher δ15N value. Higher δ15N values in the mycelial mat of the ectomycorrhizal fungi compared to those of the inoculated pine needles were also observed. These facts indicate that nitrogen isotope fractionation occurred during the nitrogen transport from mycorrhizal fungi to the host plants.

Microbial biomass in the soils of burned and unburned Japanese red pine forests in the Setouchi District, Western Japan was determined by a slightly modified chloroform fumigation-incubation method. Averages±standard deviations of microbial biomass carbon (C) of 36 unit samples in the 0-5cm soil layers at burned sites located in Ato and Nenoura were 307±206 and 789±274mg kg-1 dry soil, respectively, and that at an unburned site at Ato was 408±213 mg kg-1 dry soil. Soil microbial biomass C at the burned sites were approximately the same or slightly higher than at the unburned site. In contrast with soil microbial biomass, the above-ground plant biomass at the burned sites was about one-fifth or one-sixth of that at the unburned site. Microbial biomass C in the FH layer at the unburned site at Ato was 13.38±6.13g kg-1 dry soil. No significant fluctuations of microbial biomass were observed through 1 year in the 0-5cm soil layers at either the burned and unburned sites, nor in the FH layer at the unburned site. The ratios of microbial biomass C to total C in the soils at the burned sites were 3.2-3.3%, significantly higher than those at the unburned site (2.1%). Significant correlations were observed between microbial biomass C and some soil characteristics, such as contents of total C, total nitrogen (N) and water, in both burned and unburned soils.

Estimation of soil microbial biomass in burned and unburned Japanese red pine forests was attempted using the chloroform fumigation-incubation method. As the amount of CO2-C evolved from the fumigated soil for 10–20 days after fumigation (designated as F′) was always lower than that from the unfumigated soil during the same period (UF′), the formula, microbial biomass-C(M) = {;the amount of CO2-C evolved from the fumigated soil for 0–10 days after fumigation, F) − F′}/kc, was proposed instead of Jenkinson's conventional formula, M = (F − UF′)/kc. The kc value was also determined as 0.30 using 3 fungal and 3 bacterial cultured species as internal standards. Microbial biomass-C calculated by (F − F′)/0.30 decreased with soil depth at both the burned (Nenoura, 3.5 years after fire) and unburned (Ato) sites, showing the significant correlation with the decrease of soil respiration and organic C content along soil depth. Microbial biomass-C in the 0–2 cm soil layer at the burned site at Nenoura was 130 mg/100 g dry soil and those in the HF horizon and 0–2 cm soil layer at the unburned site at Ato were 686 and 146 mg/100 g dry soil, respectively.

Soil microbial biomass was estimated in the burned and unburned Japanese red pine forests by the chloroform fumigation-incubation method. Along with this study numbers of some microbial groups (fungal spores, actinomycetes, total bacteria, gram-negative bacteria and bacterial spores) were investigated in the same soils by dilution plate count technique.Microbial biomass-C in the 0-2cm soil layer at the burned site at Nenoura fluctuated from month to month during the period from February, 1986 to July, 1987 (34-51 months after fire) in the range from 74 2 to 134.9mg/100g dry soil, relatively low during the period from December to April and maximal in October, 1986 and June, 1987. Microbial biomass in the 0-2cm soils at the burned sites at Tennoh (4 months after fire) and Norosan (80 months after fire) and the unburned site at Ato were almost the same level as that at the burned site at Nenoura. In contrast to the relatively small fluctuations of biomass, the numbers of microorganisms, especially those of total and gram-negative bacteria, fluctuated extensively from month to month. The greater numbers of total and gram-negative bacteria appeared in October-December in the 0-2cm soil layer at the burned site and in the FH and 0-2cm soil layer at the unburned site. The numbers of all microbial groups essentially decreased in August to early-September.