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1.
Nakagawa Koki Murase Jun Asakawa Susumu Watanabe Takeshi 《Journal of Soils and Sediments》2020,20(11):4034-4041
Journal of Soils and Sediments - To reveal whether microaerophilic Fe(II)-oxidizing bacteria (FeOB) participate in the Fe(II) oxidation at the oxic-anoxic interface in flooded paddy field soil,... 相似文献
2.
Hiroto Miura Kazuhisa Mukai Keigo Sudo Satoshi Haga Yutaka Suzuki Yasuo Kobayashi Satoshi Koike 《Journal of animal science》2021,99(1)
Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1. 相似文献
3.
4.
As a new use of bamboo, bamboo cubes may be useful as a shot-blast material for surface treatments. However, a suitable processing
technique for bamboo cubes has not been established. In this study, to obtain basic knowledge regarding the processing technology
for bamboo cubes, we installed shearing blades (upper and lower blades) in a universal testing machine to test cross-sectional
shearing of bamboo. The shearing force generated in this shearing was composed of a vertical component (F
v), a forward component (F
f), and a side component (F
s). This shearing force (F
v, F
f, and F
s) and the machining accuracy were investigated under various processing conditions. The shearing force became larger as the
thickness of bamboo increased. In particular, F
v showed a tendency to increase rapidly. Changes in the shear angle of the upper blade had a remarkable influence on F
v. This result suggests that the shearing force could be greatly decreased by adjusting the shear angle. The shearing force
within bamboo of 3mm in thickness was almost unaffected by the blade angle, and the change of shearing force with increasing
clearance was almost indiscernible. It was clearly demonstrated that a large number of bamboo cubes could be made when the
shear angle was large and cross-sectional shearing was performed from the bark side. However, a consequence of a large shear
angle is that burr area increases.
Part of this article was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003 相似文献
5.
Hiroto Homma Hirofumi Shinoyama Yukihiro Nobuta Yoshie Terashima Seigo Amachi Takaaki Fujii 《Journal of Wood Science》2007,53(1):80-84
Strobilurus ohshimae is an edible mushroom, and it specifically forms its fruiting bodies on buried sugi (Cryptomeria japonica) twigs. In this research, we studied lignindegrading activity of S. ohshimae. We isolated 18 strains of S. ohshimae from various regions of Japan, and determined their lignin degradation rates on sugi wood meal medium. All the strains of
S. ohshimae degraded approximately 6%–12% of sugi lignin in 30 days, and these lignin degradation rates were 1.5–3 times higher than those of Trametes versicolor, which is a typical lignin-degrading fungus. Among the three main lignin-degrading enzymes, activity of lignin peroxidase
and manganese peroxidase was not observed, while 4340U/g of laccase was produced in 30 days. To investigate the effect of
wood species on lignin degradation by S. ohshimae, the lignin degradation rate and laccase productivity on sugi wood meal medium were compared with those on beech (Fagus crenata). In T. versicolor, both lignin degradation rate and laccase productivity were higher on beech than on sugi. Conversely, in S. ohshimae, lignin degradation rate and laccase productivity were higher on sugi than on beech. Therefore, it was suggested that coniferous lignin is not always difficult to degrade for the fungi that inhabit
softwood.
Part of this article presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004 相似文献
6.
7.
Noguchi Y Nagata H Koganei H Kodera Y Hiroto M Nishimura H Inada Y Matsushima A 《Journal of agricultural and food chemistry》2002,50(12):3540-3543
An aminopeptidase, Jc-peptidase, was purified from Japanese cedar pollen by seven steps, including precipitation with ammonium sulfate, ion-exchange chromatography, gel filtration, hydrophobic interaction chromatography on phenyl-agarose, and high-performance liquid chromatography. Purified Jc-peptidease has a molecular weight of 42 kDa and hydrolyzes the synthetic substrates of L-phenylalanyl-4-methylcoumaryl-7-amide (Phe-MCA) with Km = 5 x 10(-5) M, Tyr-MCA with Km = 7 x 10(-4) M, Leu-MCA with Km = 1 x 10(-3) M, and Met-MCA with Km = 1 x 10(-3) M. Other MCA analogues such as Arg-MCA or Glu-MCA failed to serve as its substrates. The activity was inhibited in the presence of phebestin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-valyl]-L-phenylalanine, with Ki = 4.7 x 10(-5) M, or bestatin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, with Ki = 1.1 x 10(-4) M. According to amino acid sequence analysis, the N-terminal amino group seems to be blocked. The physiological function of the aminopeptidase (Jc-peptidase) has not been clarified in vivo. 相似文献
8.
Rice fields are intensively managed, unique agroecosystems, where soil flooding is general performance for rice cultivation. Flooding the field results in reductive soil conditions, under which decomposition of organic materials proceeds during the period of rice cultivation. A large variety of organic materials are incorporated into rice soils according to field management. In this review, the kind and abundance of organic materials entering carbon cycling in the rice field ecosystem are evaluated first. Then, decomposition of plant residues and soil organic matter in rice fields is reviewed quantitatively. Decomposition of plant residues is shown to be the active process in carbon cycling in rice fields. Rice releases photosynthates into the rhizosphere (rhizodeposition), and they follow a different avenue of decomposition in soil from that of plant residues. Incorporation of rhizodeposition into microbial biomass and soil organic matter during the period of rice cultivation, and their fates after harvesting are evaluated quantitatively from 13C pulse labeled experiments. Percolating water transports inorganic and organic carbon from the plow layer to the subsoil layer. The amounts of their transport and accumulation in the subsoil layer are evaluated in relation to the amounts of soil organic C in the plow layer. Not only CO2 but also CH4 are produced in the decomposition process of organic materials in flooded rice fields. CH4 evolution from rice fields is of global concern from the viewpoint of global warming. Origins of CH4 evolved from rice fields are estimated first, followed by the fates of CH4 in rice field ecosystems. Rhizodeposition is shown to be the main origin of CH4 evolved from rice fields. Evolution to the atmosphere is not the sole pathway of CH4 produced in rice fields. The amounts of CH4 retained in soil, percolated to the subsoil layer and decomposed in soil are evaluated in the context of the amounts of CH4 efflux. Thus, this review focuses on carbon cycling in the rice field ecosystem from the viewpoints of input, decomposition, and translocation of organic materials and the fates of their end products (CO2 and CH4). 相似文献
9.
Bacterial communities associated with five kinds of microcrustaceans ( Tanycypris sp., Moina sp., Mesocyclops sp., Cypretta sp. and Heterocypris sp.) from the floodwater of a paddy field microcosm were examined by the application of denaturing gradient gel electrophoresis (DGGE) to PCR-amplified 16S rDNA products with universal bacterial primers and by sequencing of characteristic DGGE bands. The number of DGGE bands of the associated bacteria was small, indicating the association of specific bacterial members with the microcrustaceans studied, among which Tanycypris sp. showed the smallest number of bands. Principal component analysis (PCA) demonstrated that the community structure of the associated bacteria could be divided into three groups: Podocopida ( Tanycypris sp., Cypretta sp. and Heterocypris sp.), Moina sp. and Mesocyclops sp., and further analysis separated Tanycypris sp. and Heterocypris sp. into different clusters. The duration of the incubation period affected the bacteria associated with Tanycypris sp., Moina sp. and Cypretta sp. only. Nearly all of the associated bacteria belonged to Gram-negative bacteria, especially the Cytophaga-Flavobacterium-Bacteroides (CFB) group. Closest relatives of the DGGE bands common to three Podocopida and Mesocyclops sp. belonged to an invertebrate endosymbiont. 相似文献
10.
Masashi?Hatamoto Takanori?Tanahashi Jun?Murase Kazuo?Matsuya Motoki?Hayashi Makoto?Kimura Susumu?AsakawaEmail author 《Biology and Fertility of Soils》2008,44(3):527-532
To estimate the succession and phylogenetic composition of the eukaryotic communities responsible for the decomposition of
rice straw compost under flooded conditions during the cultivation period of paddy rice, denaturing gradient gel electrophoresis
(DGGE) analysis targeting 18S rDNA followed by sequencing was conducted in a Japanese paddy field. The eukaryotic communities
in rice straw compost incorporated into the flooded paddy field were influenced by the mid-season drainage and mainly composed
of fungi (Ascomycota, Zygomycota, and Chytridiomycota) and protozoa (Ciliophora, Euglyphida, and Dactylopodida), most of which
existed continuously during the cultivation period of paddy rice. The results indicated that these eukaryotic members were
associated with the decomposition of rice straw compost in paddy field soil directly or indirectly. 相似文献