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71.
将起源于黄色菌(Flavobacteriumsp.KI72)的6─氨基己酸二聚体水解酶(EⅡ)基因以质粒pTS1209为载体,转入假单孢菌PseudomonasputidaNT1126中,得到具有EⅡ高表达活性转基因株,表明以假单胞菌为宿主进行EⅡ酶分子育种的可行性,并为EⅡ酶尚处于进化中的推论提供了旁证。 相似文献
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Yurimoto H Abe K Abe M Ebihara M Fujimura A Hashiguchi M Hashizume K Ireland TR Itoh S Katayama J Kato C Kawaguchi J Kawasaki N Kitajima F Kobayashi S Meike T Mukai T Nagao K Nakamura T Naraoka H Noguchi T Okazaki R Park C Sakamoto N Seto Y Takei M Tsuchiyama A Uesugi M Wakaki S Yada T Yamamoto K Yoshikawa M Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119
Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid. 相似文献
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Shinpei Banno Hidenari Saito Hiroshi Sakai Toshihiko Urushibara Kentaro Ikeda Takeshi Kabe Isao Kemmochi Makoto Fujimura 《Journal of General Plant Pathology》2011,77(5):282-291
Verticillium longisporum and V. dahliae, causal agents of Verticillium wilt, are spreading through the cabbage fields of Gunma Prefecture. Using the V. longisporum-specific intron within the 18S rDNA and differences between ITS 5.8S rDNA sequences in Japanese isolates of V. longisporum and V. dahliae, we developed three quantitative nested real-time (QNRT) PCR assays. The QNRT-PCR quantification of V. longisporum or V. dahliae in cabbage field soil was consistent with the severity of Verticillium wilt disease in those fields. In field trials of resistant
cultivar YR Ranpo grown for three seasons in soil infested with the pathogen, disease severity and pathogen density in the
soil were significantly reduced in a field moderately contaminated by V. dahliae, but only slightly reduced in a highly contaminated field. These results suggest that continuous cultivation of a resistant
cultivar is an effective way to reduce the pathogen population. QNRT-PCR assays provide a powerful analytical tool to evaluate
the soil population dynamics of V. longisporum and V. dahliae for disease management. 相似文献
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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
77.
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
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Dhanapati NEUPANEY Jin-bo KIM Makoto ISHIOROSHI Kunihiko SAMEJIMA 《Animal Science Journal》2003,74(5):391-397
The present experiment was performed to determine some functional properties of yak butter lipids such as lipid class composition; conjugated linoleic acid (CLA) composition, differential scanning calorimetric (DSC) analysis, tyrosinase inhibition activity and antioxidant property. Yak butter lipids composition contained 98% triacylglycerols, 0.9% free fatty acids, 0.32% free sterols and 0.27% phospholipids. The CLA content in yak butter was 2.5% and the major portion was of cis‐9 and trans‐11 (90%). The DSC analysis of yak butter lipids showed a similar path for transition temperature as cow butter lipids, although the enthalpy of yak lipid was higher (40.0 mJ/mg) compared to cow butter lipids (32.0 mJ/mg). Melting point of yak butter was observed at 41°C. Yak butter with lactic acid, NaCl, citric acid and ascorbic acid showed pronounced tyrosinase inhibition activity. Vegetable oils blended with yak butter have extended the oxidation induction time. 相似文献