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111.
Nitrogen dynamics following field application of biochar in a temperate North American maize-based production system 总被引:5,自引:0,他引:5
David Güereña Johannes Lehmann Kelly Hanley Akio Enders Charles Hyland Susan Riha 《Plant and Soil》2013,365(1-2):239-254
Background and aims
Biochar additions to tropical soils have been shown to reduce N leaching and increase N use efficiency. No studies exist verifying reduced N leaching in field experiments on temperate agricultural soils or identifying the mechanism for N retention.Methods
Biochar derived from maize stover was applied to a maize cropping system in central New York State at rates of 0, 1, 3, 12, and 30 t?ha-1 in 2007. Secondary N fertilizer was added at 100, 90, 70, and 50 % of the recommended rate (108 kg N ha-1). Nitrogen fertilizer enriched with 15?N was applied in 2009 to the 0 and 12 t?ha-1 of biochar at 100 and 50 % secondary N application.Results
Maize yield and plant N uptake did not change with biochar additions (p?>?0.05; n?=?3). Less N (by 82 %; p?<?0.05) was lost after biochar application through leaching only at 100 %?N fertilization. The reason for an observed 140 % greater retention of applied 15?N in the topsoil may have been the incorporation of added 15?N into microbial biomass which increased approximately three-fold which warrants further research. The low leaching of applied fertilizer 15?N (0.42 % of applied N; p?<?0.05) and comparatively high recovery of applied 15?N in the soil (39 %) after biochar additions after one cropping season may also indicate greater overall N retention through lower gaseous or erosion N losses with biochar.Conclusions
Addition of biochar to fertile soil in a temperate climate did not improve crop growth or N use efficiency, but increased retention of fertilizer N in the topsoil. 相似文献112.
Masako Nomaguchi Masaru Yokoyama Ken Kono Emi E. Nakayama Tatsuo Shioda Naoya Doi Sachi Fujiwara Akatsuki Saito Hirofumi Akari Kei Miyakawa Akihide Ryo Hirotaka Ode Yasumasa Iwatani Tomoyuki Miura Tatsuhiko Igarashi Hironori Sato Akio Adachi 《Journal of virology》2013,87(21):11447-11461
Human immunodeficiency virus type 1 (HIV-1) replication in macaque cells is restricted mainly by antiviral cellular APOBEC3, TRIM5α/TRIM5CypA, and tetherin proteins. For basic and clinical HIV-1/AIDS studies, efforts to construct macaque-tropic HIV-1 (HIV-1mt) have been made by us and others. Although rhesus macaques are commonly and successfully used as infection models, no HIV-1 derivatives suitable for in vivo rhesus research are available to date. In this study, to obtain novel HIV-1mt clones that are resistant to major restriction factors, we altered Gag and Vpu of our best HIV-1mt clone described previously. First, by sequence- and structure-guided mutagenesis, three amino acid residues in Gag-capsid (CA) (M94L/R98S/G114Q) were found to be responsible for viral growth enhancement in a macaque cell line. Results of in vitro TRIM5α susceptibility testing of HIV-1mt carrying these substitutions correlated well with the increased viral replication potential in macaque peripheral blood mononuclear cells (PBMCs) with different TRIM5 alleles, suggesting that the three amino acids in HIV-1mt CA are involved in the interaction with TRIM5α. Second, we replaced the transmembrane domain of Vpu of this clone with the corresponding region of simian immunodeficiency virus SIVgsn166 Vpu. The resultant clone, MN4/LSDQgtu, was able to antagonize macaque but not human tetherin, and its Vpu effectively functioned during viral replication in a macaque cell line. Notably, MN4/LSDQgtu grew comparably to SIVmac239 and much better than any of our other HIV-1mt clones in rhesus macaque PBMCs. In sum, MN4/LSDQgtu is the first HIV-1 derivative that exhibits resistance to the major restriction factors in rhesus macaque cells. 相似文献
113.
Benedikt Kretner Akio Fukumori Peer‐Hendrik Kuhn Blanca Isabel Pérez‐Revuelta Stefan F. Lichtenthaler Christian Haass Harald Steiner 《Journal of neurochemistry》2013,125(1):144-156
γ‐Secretase plays a central role in the generation of the Alzheimer disease‐causing amyloid β‐peptide (Aβ) from the β‐amyloid precursor protein (APP) and is thus a major Alzheimer′s disease drug target. As several other γ‐secretase substrates including Notch1 and CD44 have crucial signaling functions, an understanding of the mechanism of substrate recognition and cleavage is key for the development of APP selective γ‐secretase‐targeting drugs. The γ‐secretase active site domain in its catalytic subunit presenilin (PS) 1 has been implicated in substrate recognition/docking and cleavage. Highly critical in this process is its GxGD active site motif, whose invariant glycine residues cannot be replaced without causing severe functional losses in substrate selection and/or cleavage efficiency. Here, we have investigated the contribution of the less well characterized residue x of the motif (L383 in PS1) to this function. Extensive mutational analysis showed that processing of APP was overall well‐tolerated over a wide range of hydrophobic and hydrophilic mutations. Interestingly, however, most L383 mutants gave rise to reduced levels of Aβ37–39 species, and several increased the pathogenic Aβ42/43 species. Several of the Aβ42/43‐increasing mutants severely impaired the cleavages of Notch1 and CD44 substrates, which were not affected by any other L383 mutation. Our data thus establish an important, but compared with the glycine residues of the motif, overall less critical functional role for L383. We suggest that L383 and the flanking glycine residues form a spatial arrangement in PS1 that is critical for docking and/or cleavage of different γ‐secretase substrates. 相似文献
114.
Yoshimasa Ishizaki Chigusa Hayashi Kunio Inoue Masayuki Igarashi Yoshiaki Takahashi Venugopal Pujari Dean C. Crick Patrick J. Brennan Akio Nomoto 《The Journal of biological chemistry》2013,288(42):30309-30319
Because tuberculosis is one of the most prevalent and serious infections, countermeasures against it are urgently required. We isolated the antitubercular agents caprazamycins from the culture of an actinomycete strain and created CPZEN-45 as the most promising derivative of the caprazamycins. Herein, we describe the mode of action of CPZEN-45 first against Bacillus subtilis. Unlike the caprazamycins, CPZEN-45 strongly inhibited incorporation of radiolabeled glycerol into growing cultures and showed antibacterial activity against caprazamycin-resistant strains, including a strain overexpressing translocase-I (MraY, involved in the biosynthesis of peptidoglycan), the target of the caprazamycins. By contrast, CPZEN-45 was not effective against a strain overexpressing undecaprenyl-phosphate–GlcNAc-1-phosphate transferase (TagO, involved in the biosynthesis of teichoic acid), and a mutation was found in the tagO gene of the spontaneous CPZEN-45-resistant strain. This suggested that the primary target of CPZEN-45 in B. subtilis is TagO, which is a different target from that of the parent caprazamycins. This suggestion was confirmed by evaluation of the activities of these enzymes. Finally, we showed that CPZEN-45 was effective against WecA (Rv1302, also called Rfe) of Mycobacterium tuberculosis, the ortholog of TagO and involved in the biosynthesis of the mycolylarabinogalactan of the cell wall of M. tuberculosis. The outlook for WecA as a promising target for the development of antituberculous drugs as a countermeasure of drug resistant tuberculosis is discussed. 相似文献
115.
Nobuyuki Kawasaki Kazuhiro Komatsu Ayato Kohzu Noriko Tomioka Ryuichiro Shinohara Takayuki Satou Fumiko Nara Watanabe Yuya Tada Koji Hamasaki M. R. M. Kushairi Akio Imai 《Applied and environmental microbiology》2013,79(23):7160-7168
Incubation experiments using filtered waters from Lake Kasumigaura were conducted to examine bacterial contribution to a dissolved organic carbon (DOC) pool. Bacterial abundance, bacterial production, concentrations of DOC, total dissolved amino acids (TDAA), and total dissolved neutral sugars (TDNS) were monitored during the experiments. Bacterial production during the first few days was very high (20 to 35 μg C liter−1 day−1), accounting for 40 to 70% of primary production. The total bacterial production accounted for 34 to 55% of the DOC loss during the experiment, indicating high bacterial activities in Lake Kasumigaura. The DOC degradation was only 12 to 15%, whereas the degradation of TDAA and TDNS ranged from 30 to 50%, suggesting the preferential usage of TDAA and TDNS. The contribution of bacterially derived carbon to a DOC pool in Lake Kasumigaura was estimated using d-amino acids as bacterial biomarkers and accounted for 30 to 50% of the lake DOC. These values were much higher than those estimated for the open ocean (20 to 30%). The ratio of bacterially derived carbon to bulk carbon increased slightly with time, suggesting that the bacterially derived carbon is more resistant to microbial degradation than bulk carbon. This is the first study to estimate the bacterial contribution to a DOC pool in freshwater environments. These results indicate that bacteria play even more important roles in carbon cycles in freshwater environments than in open oceans and also suggests that recent increases in recalcitrant DOC in various lakes could be attributed to bacterially derived carbon. The potential differences in bacterial contributions to dissolved organic matter (DOM) between freshwater and marine environments are discussed. 相似文献
116.
Hiroshi Kadokura Michiko Saito Akio Tsuru Akira Hosoda Takao Iwawaki Kenji Inaba Kenji Kohno 《Biochemical and biophysical research communications》2013
ERdj5 (also known as JPDI) is a member of PDI family conserved in higher eukaryotes. This protein possesses an N-terminal J domain and C-terminal four thioredoxin domains each having a redox active site motif. Despite the insights obtained at the cellular level on ERdj5, the role of this protein in vivo is still unclear. Here, we present a simple method to purify and identify the disulfide-linked complexes of this protein efficiently from a mouse tissue. By combining acid quenching and thiol-alkylation, we identified a number of potential redox partners of ERdj5 from the mouse epididymis. Further, we show that ERdj5 indeed interacted with two of the identified proteins via formation of intermolecular disulfide bond. Thus, this approach enabled us to detect and identify redox partners of a PDI family member from an animal tissue. 相似文献
117.
Shin-ichi Ikeda Yoshifumi Tamura Saori Kakehi Kageumi Takeno Minako Kawaguchi Takahiro Watanabe Fumihiko Sato Takeshi Ogihara Akio Kanazawa Yoshio Fujitani Ryuzo Kawamori Hirotaka Watada 《Biochemical and biophysical research communications》2013
Exercise enhances insulin sensitivity in skeletal muscle, but the underlying mechanism remains obscure. Recent data suggest that alternatively activated M2 macrophages enhance insulin sensitivity in insulin target organs such as adipose tissue and liver. Therefore, the aim of this study was to determine the role of anti-inflammatory M2 macrophages in exercise-induced enhancement of insulin sensitivity in skeletal muscle. C57BL6J mice underwent a single bout of treadmill running (20 m/min, 90 min). Twenty-four hours later, ex vivo insulin-stimulated 2-deoxy glucose uptake was found to be increased in plantaris muscle. This change was associated with increased number of CD163-expressing macrophages (i.e. M2-polarized macrophages) in skeletal muscle. Systemic depletion of macrophages by pretreatment of mice with clodronate-containing liposome abrogated both CD163-positive macrophage accumulation in skeletal muscle as well as the enhancement of insulin sensitivity after exercise, without affecting insulin-induced phosphorylation of Akt and AS160 or exercise-induced GLUT4 expression. These results suggest that accumulation of M2-polarized macrophages is involved in exercise-induced enhancement of insulin sensitivity in mouse skeletal muscle, independently of the phosphorylation of Akt and AS160 and expression of GLUT4. 相似文献
118.
Yukiko Tokitomo Yūko Shimono Akio Kobayashi Tei Yamanishi 《Bioscience, biotechnology, and biochemistry》2013,77(7):1873-1877
The attractive and characteristically sweet aroma components of baelfruit—a tropical fruit— were investigated. The aroma concentrates possessing the sweet floral and somewhat terpene-like aroma were obtained from both the pulp and peel of fresh baelfruits by means of lyophilization and ether extraction, being analyzed mainly by GC-MS, A total of 39 components were identified. Among these components, terpene alcohols and β-βonone were considered to contribute to the aroma of baelfruit. At optimum ripeness, the fruit with excellent flavor contained a large quantity of an isomeric compound of 3,7-dimethyl-1,5,7-octatrien-3-ol. This compound couldn’t be found in unripe fruit, and seems to be ?mportant in making the baelfruit flavor attractive. 相似文献
119.
Daizo Koga Taiji Imoto Shuhei Tanaka Akio Ide Kazuyoshi Yagishita 《Bioscience, biotechnology, and biochemistry》2013,77(9):1941-1948
The effects of detergents on the lysozyme-catalyzed hydrolysis of Micrococcus lysodeikticus cells were investigated by changing the concentration of Na-phosphate buffer and pH in the presence or absence of sucrose. Also, a parallel study of the hydrolysis of glycolchitin by lysozyme was conducted and compared to the lytic reaction. Electron microscopy was utilized to follow the changes in cell morphology during the various treatments.None of the detergents changed turbidity of the cell suspension. However, they did affect the change in turbidity during lysis in unique ways. SDS, which is an anionic detergent, inhibited lysozyme activity and its addition to the reaction mixture caused a rapid and large decrease in the turbidity. Brij 35 and Triton X-100, which are non-ionic detergents, did not inhibit lysozyme activity, but their presence in the reaction mixture changed the rate of turbidity change. Apparently non-ionic detergents disrupt only the protoplast, while anionic detergents disrupt both the protoplast and the damaged cell. The lytic mechanism of M. lysodeikticus by lysozyme was discussed in detail. 相似文献
120.
Akira K. Tanaka Akio Kobayashi Kyohei Yamashita 《Bioscience, biotechnology, and biochemistry》2013,77(12):2537-2542
1-O-Palmitoyl-d-glucopyranose was prepared by the selective 1-O-acylation of 4,6-O-benzylideneglucose followed by hydrogenolysis of the protecting group. 1-O-Oleoyl-d-glucopyranose was synthesized from the corresponding benzylidene derivative by selective hydrolysis in acetic acid. This procedure constitutes a useful method for the synthesis of 1-O-acyl-d-glucopyranoses containing unsaturated carboxylic acids. However, 4,6-O-benzylidene-l-O-linolenoyl-d-glucopyranose was converted to 3-O-linolenoyl-d-glucopyranose by the acidic hydrolysis due to acyl migration.Synthesized glucosyl esters were inactive in the bean second-internode bioassay. However, it was found that 3-O-linolenoyl-d-glucopyranose had a promoting activity on germination of pollen and growth of pollen tube. 相似文献