In vitro reduction of manganese dioxide by a ferrireductase system from the white-rot fungus <Emphasis Type="Italic">Phanerochaete sordida</Emphasis> YK-624     

Hirofumi?HiraiEmail author  Takanori?Itoh  Tomoaki?Nishida 《Journal of Wood Science》2003,49(6):538-542

Reduction of manganese dioxide is demonstrated for an in vitro ferrireductase system that includes NADPH-dependent ferrireductase and the iron-binding compound (IBC) isolated from the white-rot fungus Phanerochaete sordida YK-624. The Fe(II)–IBC complex was more effective in reducing manganese dioxide to Mn(II) than were complexes of Fe(II) and organic acids of low molecular weight such as nitrilotriacetate, although IBC also reduced manganese dioxide to Mn(II) in the absence of Fe(II). The generated Fe(III)–IBC complex was a better substrate for NADPH-dependent ferrireductase than were other ferric chelates, suggesting that the Fe(III)–IBC complex is reduced to an Fe(II) complex by NADPH-dependent ferrireductase. Moreover, production of the Fe(III)–IBC complex by the reduction of manganese dioxide in a reaction system containing Fe(II) and IBC was observed to be coupled to reduction of the Fe(III)–IBC complex by NADPH-dependent ferrireductase. These results indicate that the ferrireductase system of P. sordida YK-624 plays an important role in the reduction of manganese dioxide, which is necessary for the production and function of manganese peroxidase.  相似文献   

In vitro screening of angiotensin I-converting enzyme inhibitors from Japanese cedar (Cryptomeria japonica)     

Yuji Tsutsumi  Ayako Shimada  Akiko Miyano  Tomoaki Nishida  Tohru Mitsunaga 《Journal of Wood Science》1998,44(6):463-468

Screening and isolation of angiotensin I-converting enzyme (ACE) inhibitors from Japanese cedar (Cryptomeria japonica) based on the in vitro ACE inhibitory assay were attempted. The ethanol extract from outer bark showed the highest inhibitory activity (IC₅₀ is 16g/ml) among 24 extracts prepared from roots, leaves, heartwood, sapwood, inner bark, and outer bark by successive extraction with four solvents. The fractionation of the outer bark ethanol extract followed by the bioassay resulted in the isolation of two strong ACE inhibitors, catechin and dimeric procyanidin B3. The bioassay of three flavan-3-ols including (+)-catechin and six flavones revealed that most of these compounds have high ACE inhibitory activity. The results suggest that the phenolic hydroxyl group at the C7 position and heterocyclic oxygen atom of these compounds are important for expressing the inhibitory activity.  相似文献   

Structural changes of residual lignin in softwood kraft pulp treated with manganese peroxidase     

Katsunobu Ehara  Yuji Tsutsumi  Tomoaki Nishida 《Journal of Wood Science》1998,44(4):327-331

Structural changes of residual lignin in unbleached softwood kraft pulp (SWKP) during manganese peroxidase (MnP) treatment were investigated to obtain some understanding of the biobleaching action of SWKP with MnP treatment. Alkaline-extracted lignin from darkened SWKP by MnP showed more intense color and contained moreo-quinone than that from control SWKP. However, no difference in the conjugated-carbonyl was observed between the lignins from MnP-treated and control SWKP. The nitrobenzene oxidation analysis revealed that oxidative condensation of non-condensed lignin in SWKP occurs during an early stage of MnP treatment. These observations were supported by the model experiment in which the lignin prepared from control SWKP was subjected to MnP treatments three times, and the changes of color and functional groups in the lignin were determined after each treatment. These results suggested that an increase ino-quinone and the condensation reaction of non-condensed lignin in SWKP are responsible for the characteristic darkening of SWKP during MnP treatment. It was also ascertained that darkened lignin was degraded and brightened by repeated MnP treatments.  相似文献   

Application of crude and recombinant ELISAs and immunochromatographic test for serodiagnosis of animal trypanosomosis in the Umkhanyakude district of KwaZulu-Natal province,South Africa     

Thu-Thuy NGUYEN  Mono Sophie MOTSIRI  Moeti Oriel TAIOE  Moses Sibusiso MTSHALI  Yasuyuki GOTO  Shin-Ichiro KAWAZU  Oriel Matlhahane Molifi THEKISOE  Noboru INOUE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(2):217-220

A total of 231 serum samples were collected from sheep (n=9), goats (n=99) and cattle (n=123) in northeastern KwaZulu-Natal, South Africa. Trypanosome infection was detected using Trypanosoma brucei brucei crude antigen (TbbCA) and T. congolense crude antigen (TcoCA) ELISA assays. Recombinant antigen (T. evansi GM6 which consisted of 4 repeat domains, TeGM6-4r) ELISA and immunochromatographic test (ICT) were also used. Crude antigen ELISA, TeGM6-4r-ELISA and ICT detected 27.3%, 29% and 19.9% of trypanosome seropositive samples, respectively. Trypanosome infection prevalence in cattle and goats was 35.8–46.3% and 0–9.1%, respectively. Out of 9 sheep serum samples, 2–4 sera (22.2–44.4%) were positive. The detection performance of crude and recombinant antigen ELISAs was relatively similar (K=0.6–0.7); both are recommended for reference diagnosis and large scale epidemiological surveys. There is potential application for ICT in on-site diagnosis, but its sensitivity should be improved.  相似文献   

Polyethylene degradation by lignin-degrading fungi and manganese peroxidase     

Yuka Iiyoshi  Yuji Tsutsumi  Tomoaki Nishida 《Journal of Wood Science》1998,44(3):222-229

Degradation of high-molecular-weight polyethylene membrane by lignin-degrading fungi, IZU-154, Phanerochaete chrysosporium, and Trametes versicolor, was investigated under various nutritional conditions. IZU-154 showed the most significant polyethylene degradation among the three lignin-degrading fungi under nitrogen- or carbon-limited culture conditions. Furthermore, for T. versicolor and P. chrysosporium, the addition of Mn(II) into nitrogen- or carbon-limited culture medium enhanced polyethylene degradation. These results suggest that polyethylene degradation is related to ligninolytic activity of lignin-degrading fungi. Treatment of polyethylene membrane with partially purified manganese peroxidase (MnP) caused significant degradation in the presence of Tween 80, Mn(II), and Mn(III) chelator. This result demonstrates that MnP is the key enzyme in polyethylene degradation by lignin-degrading fungi.This study was presented in part at the 9th International Symposium on Wood and Pulping Chemistry, Montreal, Canada, June 9–12, 1997  相似文献   

Myricanol and myricanone biosynthesis in <Emphasis Type="Italic">Myrica rubra</Emphasis>: incorporation of two molecules of 4-coumaric acid     

Shingo Kawai  Kyousuke Nakata  Masako Ohashi  Tomoaki Nishida 《Journal of Wood Science》2008,54(3):256-260

After feeding experiments of Myrica rubra young shoots with 4-[8,9-¹³C₂]coumaric acid, mass spectrometric analyses revealed that the cyclic diarylheptanoids, myricanol and myricanone, were derived from two molecules of 4-coumaric acid. ¹³C Nuclear magnetic resonance analysis of myricanol isolated after administration of 4-[8,9-¹³C₂]coumaric acid demonstrated that the C-8 and C-9 atoms of 4-coumaric acid are incorporated into C-8, C-9, C-11, and C-12 of the corresponding myricanol. Part of this report was presented at the 56th Annual Meeting of the Japan Wood Research Society, Akita, August 2006  相似文献   

Functions and structure of roots and their contributions to salinity tolerance in plants     

Ichirou Karahara  Tomoaki Horie 《Breeding Science》2021,71(1):89

Soil salinity is an increasing threat to the productivity of glycophytic crops worldwide. The root plays vital roles under various stress conditions, including salinity, as well as has diverse functions in non-stress soil environments. In this review, we focus on the essential functions of roots such as in ion homeostasis mediated by several different membrane transporters and signaling molecules under salinity stress and describe recent advances in the impacts of quantitative trait loci (QTLs) or genetic loci (and their causal genes, if applicable) on salinity tolerance. Furthermore, we introduce important literature for the development of barriers against the apoplastic flow of ions, including Na⁺, as well as for understanding the functions and components of the barrier structure under salinity stress.  相似文献   

CH4 flux in an alas ecosystem formed by forest disturbance near Yakutsk,Eastern Siberia,Russia     

Tomoaki Morishita  Ryusuke Hatano  Roman V. Desyatkin 《Soil Science and Plant Nutrition》2013,59(3):369-377

Abstract

Quartz and mica contents were determined as a function of particle size of soils over quartz and mica-free basalts in northwestern Kyushu and San-in. The contents of both minerals were much higher in the surface soil horizons than in the lower horizons. Quartz particle size distribution (predominantly 2 to 53 μm) and surface morphology (chip or shard, not euhedral) which are similar to those in the north central Pacific pelagic sediments and Hawaiian soils, indicated that quartz is added as aerosolic dust and loess carried by the circumpolar Westerly Winds from Asian semi-arid and arid regions. Close proximity to the eolian sources was deduced by somewhat coarser texture of the present soil quartz. Lower surface soil quartz content, relative to that in the Hawaiian soils was interpreted as indicating a younger landscape age caused by intensive denudation. The covariant relation between the quartz and miea eontents of soils may suggest that at least a portion of the micaceous minerals and quartz in Ando soils of Japan also has a tropospheric origin.  相似文献   

Estimation of mean tree height using small-footprint airborne LiDAR without a digital terrain model   总被引：1，自引：0，他引：1  

Kazukiyo Yamamoto  Tomoaki Takahashi  Yousuke Miyachi  Naoto Kondo  Shinichi Morita  Motohiko Nakao  Takashi Shibayama  Yoshiyuki Takaichi  Masashi Tsuzuku  Naoaki Murate 《Journal of Forest Research》2011,16(6):425-431

In order to estimate mean tree height using small-footprint airborne light detection and ranging (LiDAR) data, a digital terrain model (DTM), which is a continuous elevation model of the ground surface, is usually required. However, generating accurate DTMs in mountainous forests using only the LiDAR data is laborious and time consuming, because it requires human-assisted methods, especially in the forests with poor laser penetration rates. Based on our previous finding that a hypothetical continuous surface model passing through the predominant tree tops (hereafter, called the “top surface model” or TSM) might be nearly parallel to a DTM, we assumed that the vertical difference between the TSM and the ground return was the mean tree height. According to this assumption, we propose a new methodology that does not require a DTM to estimate mean tree height. This method completely, automatically, and directly estimates mean tree height (MTH _E) from the LiDAR data without requiring a regression analysis using reference data. From the relationships between the MTH _E and the observed mean tree height (MTH _O) in different hinoki cypress forests, we demonstrate that this method effectively estimates the mean tree height with nearly 1-m accuracy.  相似文献   

Immunohistochemical and ultrastructural analyses of cytoplasmic blood plasma inclusions of rat hepatocytes     

Tochitani T  Toyosawa K  Matsumoto I  Kouchi M  Michimae Y  Koujitani T  Funabashi H  Seki T 《Journal of toxicologic pathology》2011,24(4):245-249

In the present study, we investigated the histological, immunohistochemical and ultrastructural characteristics of cytoplasmic blood plasma inclusions that spontaneously occurred in a rat liver. Histologically, a number of cytoplasmic inclusions were observed in the liver of an 8-week-old female SD rat. These inclusions were strongly positive for PAS staining and resistant to diastase digestion. Immunohistochemical analyses revealed that these inclusions were positive for albumin and IgG; however, most of them were negative for LAMP-1 and LAMP-2. Ultrastructurally, the inclusions were surrounded by limiting membranes and composed of moderately electron dense, homogenous materials. These characteristics described here represent valuable information for pathological examination in toxicity studies.  相似文献