Arata Katayama

Endocrine disruptors in the environment (IUPAC Technical Report)

Many chemical substances of natural or anthropogenic origin are suspected or known to be endocrine disruptors, which can influence the endocrine system of life. This observation has led to increased interest on the part of the public and the media, as well as to a steep rise of research activities in the scientific community. New papers and results are presented so fast that it is impossible to give a complete review of this emerging research field. Therefore, this paper tries to give insight into some topics of the great scope of endocrine disruptors in the environment. To get a general idea of the biochemical and biological background, some parts of the endocrine systems of mammalians and nonmammalians are explained. The sections that follow describe important mechanisms of endocrine disruption such as interactions with hormone receptors. Test strategies for anthropogenic chemicals on various organisms are critically reviewed with respect to their problems and gaps concerning endocrine disruptors. The main emphasis of the paper is on the chemical substances suspected or known to be endocrine disruptors. To get a better comprehension of their behavior in the environment, physicochemical data such as water solubility or Kow, as well as information about their use and/or function are reviewed and compared. The main routes of exposure for most chemicals are shortly described, and data about concentrations in the environment (soil/sediment, water) are detailed.

Characteristics of biochar and its application in remediation of contaminated soil

Biochar is produced by thermal decomposition of biomass under oxygen-limited conditions (pyrolysis), and it has received attention in soil remediation and waste disposal in recent years. The characteristics of biochar are influenced mainly by the preparation temperature and biomass. Higher pyrolysis temperature often results in the increased surface area and carbonized fraction of biochar leading to high sorption capability for pollutants. Biochars derived from various source materials show different properties of surface area, porosity and the amount of functional groups which are important concerning on the effect of biochar. Biochar has been proved to be effective in improving soil properties and increasing crop biomass. It has also been suggested that it can even enhance crop resistance to disease. Biochar has recently been used to remediate soil with both heavy metal and organic pollutants. The mechanism is electrostatic interaction and precipitation in the case of heavy metal, and the surface adsorption, partition and sequestration in the case of organic contaminants. However, application of biochar in soil has been shown to result in decreased efficacy of pesticides, which indicates a trade-off between the potentially promising effect of biochar on pesticide remediation and its negative effect on pesticide efficacy. While arguments on the effectiveness of biochar appear sound, further research is needed prior to widespread application of biochar in soil remediation.

Analysis of Respiratory Quinones in Soil for Characterization of Microbiota

Abstract Method for the analysis of respiratory quinones in soil was developed to characterize soil microbiota. The respiratory quinones were extracted with a mixture of chloroform and methanol using a Wahling blender or a sonicator and cleaned-up by a silicagel column cartridge. The quinone species were determined by reverse-phase high performance liquid chromatography. Spectra of peaks were measured with a photodiode array detector to examine the purity. More than 90% of extractable quinones in soil were recovered by three extractions. The recovery of quinones, added to soil as freeze-dried powder of microorganisms, was higher than 96%. This procedure led to higher representative results as follows. Fluctuations within 95% of cumulative frequency were 13% for the extracted amount of quinones and 20% for the dissimilarity, respectively. The quinone profiles of four soils were determined as follows: a soil from the aerobic layer of a paddy field, an ando soil and two yellow upland soils which had received...

Quantitative analyses of the change in microbial diversity in a bioreactor for wastewater treatment based on respiratory quinones

Abstract The change in microbial diversity in a submerged aerobic biofilter, into which a persistent chemical of dimethylformamide was fed, were analyzed based on the quinone profiles using a new diversity index of the respiratory quinones (DQ) and an index of equitability of the distribution of quinone species (EQ) originally proposed in this study: DQ=(∑ f 1/2 k ) 2 , EQ=DQ/ n . Where, f k is the mole fraction of quinone species k and n is the number of quinone species, respectively. The DQ value increases with an increase in the number and the equitability of the distribution of quinone species. In the case where the mole fractions of all quinone species are equal, the value of DQ becomes equal to the number of quinone species and the EQ value becomes 1. A simulation analyses shows that DQ has a higher sensitivity to the change in number of quinone species than Shannons index, i.e. one of the most widely used diversity indices. The relative sensitivity of DQ to the change in mole fraction of quinone species is higher than that of Shannons diversity index for natural ecosystems in which many kinds of quinone species exist and occupy smaller fractions. The quinone profiles of the biofilm significantly changed and the values of DQ and EQ increased during the acclimation of the biofilm to dimethylformamide in the biofilter. The plot of the mole fraction of dominant quinone species to the DQ values showed higher sensitivity to the change in the microbial community. These results indicated that DQ and EQ are useful indices for the evaluation of the changes in the microbial community in response to environmental conditions.

Long-term changes in microbial community structure in soils subjected to different fertilizing practices revealed by quinone profile analysis

Abstract Quinone profile analysis of stored air-dried soils gave an approximation of the long-term changes in the microbial community structure in four soils subjected to different types of fertilizer application from 1987 to 1997: unfertilized soil (NF-soil), soil amended with chemical fertilizers (CF-soil), soil amended with chemical fertilizers and 40 t ha-1 y-1 of farmyard manure (CF+ FYM-soil), and soil amended with 400 t ha-1 y-1 of farmyard manure (FYM-soil). The carbon content increased, and the soil pH remained higher in the soils receiving farmyard manure. Principal component analysis of the quinone profiles of the soils indicated that the microbial community structure showed a high similarity among the four soils before the onset of cultivation and changed to a different community structure specific to the respective fertilizing practices except for the NF-soil. The specific quinone profile became stable after two cropping seasons in the FYM-soil, after 10 cropping seasons in the CF+ FYM-soil a...

A novel Dehalobacter species is involved in extensive 4,5,6,7-tetrachlorophthalide dechlorination.

ABSTRACT The purpose of this study was the enrichment and phylogenetic identification of bacteria that dechlorinate 4,5,6,7-tetrachlorophthalide (commercially designated “fthalide”), an effective fungicide for rice blast disease. Sequential transfer culture of a paddy soil with lactate and fthalide produced a soil-free enrichment culture (designated the “KFL culture”) that dechlorinated fthalide by using hydrogen, which is produced from lactate. Phylogenetic analysis based on 16S rRNA genes revealed the dominance of two novel phylotypes of the genus Dehalobacter (FTH1 and FTH2) in the KFL culture. FTH1 and FTH2 disappeared during culture transfer in medium without fthalide and increased in abundance with the dechlorination of fthalide, indicating their growth dependence on the dechlorination of fthalide. Dehalobacter restrictus TEA is their closest relative, with 97.5% and 97.3% 16S rRNA gene similarities to FTH1 and FTH2, respectively.

Effects of compost maturity on growth of komatsuna (brassica rapa var. pervidis) in neubauer's pot: I. Comparison of Growth in Compost Treatments with That in Inorganic Nutrient Treatments as Controls

Growth of komatsuna (Brassica Rapa var. pervidis) was studied on Fujimi sandy soil treated with garbage composts of different maturity using Neubauers pot under artificial light and controlled temperature. Inhibitory effect on komatsuna growth was evaluated by comparing the growth in the compost treatments with that in inorganic nutrient treatments with the same amount of inorganic nitrogen as in the composts. Under a loading of 10 g dry weight per pot, which is equivalent to 10 dry ton of compost per 1 ha in land application, the treatment with immature composts resulted in considerably lower yields compared with the controls. Inhibitory effect was observed especially in the early stages of growth. The well-mature composts gave higher or equal yields compared with the controls. On the other hand, with a loading of 20 g per pot, all the compost treatments resulted in lower yields than those of the controls regardless of compost maturity. The inhibitory effect was mainly observed in the later stages of gr...

Chemical and microbial properties of various compost products

Abstract Chemical and microbial characterizations were carried out for forty-four compost products, whose raw materials were classified into seven categories: wood, coffee ground, grass, buckwheat shells, animal manure, food waste, and others. Microbial community structure in the composts was examined by quinone profile analysis. Values of the chemical and microbial properties varied considerably as follows: moisture content 3.1–82.7%, pH 4.38–9.44, electric conductivity (EC) 0.12–17.08 mS cm−1, total carbon (TC) content 16.9–51.0%, total nitrogen (TN) content 0.61–9.83%, C / N ratio 5.2–53.1, ash content 4.2–63.2%, total quinone (TQ) content 0.0–215.2 µmol kg−1 dry sample, and value of quinone diversity (DQ) index 0.0–20.8. The wide range in the values expressed the diversity of the chemical and microbial properties of various compost products. The chemical properties were related to the raw materials while the microbial properties tended to be less related. Total menaquinone contents were higher than the total ubiquinone contents in most of the composts. The common major quinone species was menaquinone-7, indicating the predominance of Bacillus. The average mole fractions of menaquinones with partially saturated and long side-chains accounted for about 37% of the TQ content, indicating the proliferation of Actinobacteria. Multiple regression analysis suggested that microbial properties were significantly related to the moisture content, pH, and C / N ratio of the compost products. The DQ increased with the increase of the quinone contents and became stable at the value of about 16.5 in the composts with more than 50 nmol kg−1 of quinones. At the same time these values were observed only in the composts with C / N ratios lower than 20.

Humin as an electron mediator for microbial reductive dehalogenation.

We report that humins extracted as the solid fractions from paddy soils or sediment are involved in extracellular electron transfer, coupled with microbial reductive dehalogenation of pentachlorophenol (PCP), by serving as both electron acceptor and electron donor. In our system, humin is requisite for the dechlorination of PCP, and this activity cannot be maintained when humin is replaced with soluble humic substances or related compounds, including 0.1 M NaOH-extracted humic acid from soil, Aldrich humic acid, and anthraquinone-2,6-disulfonate. The function of humins is stable against treatments with H(2)O(2) (30%, 30 min), HCl (0.1 M, 48 h), NH(2)OH · HCl (0.1 M, 48 h), NaBH(4) (0.1 M, 15 h), and heat (121 °C, 30 min). Cyclic voltammograms indicated that humin harbors redox-active moieties, and electron spin resonance suggested that quinone moieties within humin are the redox-active centers. Fourier-transform infrared and nuclear magnetic resonance analyses verified the presence of the aryl carbonyl carbon group in humin. Although the proportion of redox-active carbon is very small, the potential electron-mediating ability is not negligible. The finding that humin, in solid form, is redox active has important implications for in situ bioremediation, given the wide distribution of humin and the diversity and ubiquity of humic substance-utilizing microorganisms.

Activities of some soil enzymes in different land use systems after deforestation in hilly areas of West Lampung, South Sumatra, Indonesia

Abstract The activities of acid and alkaline phosphatases, β-glucosidase and urease were determined in soils under different land-use systems after deforestation in hilly areas of West Lampung, South Sumatra, Indonesia. Soil samples (topsoils, 0–20 cm and subsoils, 20–40 cm) were collected from 5 different locations, each consisting of 4 different land-use systems: i.e. primary forests, secondary forests, coffee plantations, and cultivated lands (upland fields and paddy fields). Enzyme analyses showed that the activities of phosphatases, β-glucosidase, and urease were significantly higher in most cases in the primary forests or in the secondary forests than in the other two land-use systems, indicating that clearing the forests and converting them to other land-use systems significantly disturbed the growth of enzyme-producing organisms. There was no significant difference in the enzymatic activities between cultivated upland fields and paddy fields. The activity of alkaline phosphatase showed the most dr...