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41.
Analysis of the chemical components from the culture broth of the marine bacterium Saccharomonospora sp. CNQ-490 has yielded three novel compounds: saccharobisindole (1), neoasterric methyl ester (2), and 7-chloro-4(1H)-quinolone (3), in addition to acremonidine E (4), pinselin (5), penicitrinon A (6), and penicitrinon E (7). The chemical structures of the three novel compounds were elucidated by the interpretation of 1D, 2D nuclear magnetic resonance (NMR), and high-resolution mass spectrometry (HRMS) data. Compound 2 generated weak inhibition activity against Bacillus subtilis KCTC2441 and Staphylococcus aureus KCTC1927 at concentrations of 32 μg/mL and 64 μg/mL, respectively, whereas compounds 1 and 3 did not have any observable effects. In addition, compound 2 displayed weak anti-quorum sensing (QS) effects against S. aureus KCTC1927 and Micrococcus luteus SCO560.  相似文献   
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Interactions and self-organization in the soil-microbe complex   总被引:6,自引:0,他引:6  
Soil is the most complicated biomaterial on the planet. As with any material, the physical habitat is of prime importance in determining and regulating biological activity. However, until recently the opaque nature of soil has meant that any interrogation of its interior architecture has been relatively rudimentary, restricted to simple qualitative expressions of the physical heterogeneity that fail to relate to any specific function. However, new techniques and insights into the biophysical and biochemical processes of this inner space are leading to the developments of theoretical frameworks and experimental approaches that will allow us to sustainably manage Earth's most important resource. We introduce the concept that the soil-microbe system is self-organized and suggest new priorities for research based on an integrative approach that combines biochemistry and biophysics.  相似文献   
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This study investigates the effects of embryonic exposure to two different antioxidants on growth and development in fish. Zebrafish (Danio rerio) embryos (100 per group) were exposed to lipoic acid (LA, 6–12 μM) or ascorbic acid (AA, 100–200 μM) and the hatching rate, standard lengths (SL) at hatching, development and growth post‐hatching monitored. The SLs at hatching were increased (P<0.05) in both antioxidant‐exposed groups relative to the controls, with no effect on yolk reserves. This enhanced development persisted up to 15 days post hatching. At hatching, cell proliferation rates (P<0.0005) and basic fibroblast growth factor (P<0.001), were greater in the antioxidant‐exposed fish than in the controls (0 μM antioxidant); no oxidative DNA damage was detected (P>0.05). Activity of the endogenous antioxidant enzyme superoxide dismutase was greater (P<0.001) in LA‐treated fish than in the controls. The results suggest that embryonic treatment of zebrafish with LA or AA during embryogenesis enhanced cell proliferation, leading to increased somatic growth in the larval stages, persisting into the juvenile stage. The findings support the treatment of embryonic fish with antioxidants for enhanced results in aquaculture.  相似文献   
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Indigenous populations of white clover (Trifolium repens L) collected from Europe, the Mediterranean area, as well as other parts of the world have been grown as spaced plants at Aberystwyth. Data were collected on various morphological characters, green weight and leaf marks.Leaflet length, width, area, plant height and green weight were all strongly correlated, but not the flowering date or leaflet shape (= ratio length/width).The mean leaflet size of Mediterranean populations (the supposed centre of origin) was very variable, and decreased northwards. All British populations were uniformly small leaved.Most of the populations were much less vigorous than the bred control varieties and only a few equalled them. Nevertheless some of the introductions exhibited seasonal growth patterns, especially growth into the autumn, and large leaves that could be usefully incorporated in improved varieties. Populations originating one step back towards the centre of origin will probably be the most useful when immediate adaptation is the aim.  相似文献   
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This study was conducted to evaluate the supplementation of glutamic acid(Glu)to reduced protein diets on the performance of weanling pigs.One hundred and eighty crossbred weanling pigs([YorkshireLandrace]Duroc,21 d old)having similar body weight(BW)of 6.45 kg were randomly allotted to 1 of 6 dietary treatments(5 pigs per pen[2 barrows and 3 gilts];6 pens per treatment)based on BW and sex during a 6-week trial.Dietary treatments consisted of positive control(PC)diet formulated to have 226.9,205.6,and 188.8 g crude protein(CP)during phases 1,2,and 3,respectively,and negative control(NC)diets with 20 g CP reduction from PC diets and addition of Glu with increasing levels,resulting in the calculated Lys-to-Glu ratios of 1:2.25,1:2.30.1:2.35,1:2.40,and 1:2.45,designated as NC,NC1,NC2,NC3,and NC4,respectively.The BW of pigs receiving PC diet was higher(P<0.05)than those receiving NC diet at d 7,21 and 42.A higher(P<0.05)average daily gain(ADG)from d 1 to 7,8 to 21,22 to 42 and during the overall experiment period was observed in pigs fed PC than NC diet.Pigs fed NC diets including the graded level of Glu linearly increased(P<0.05)BW at d 42,ADG and gain-to-feed ratio(G:F)during the overall experimental period.In addition,trends in linear increase in BW(P=0.056)at d 7 and ADG from d 1 to 7 and d 22 to 42(linear effect,P=0.081,P=0.058 respectively)were observed.A tendency in the linear increment of NH3(P=0.082)at d 21 and linear reduction in methyl mercaptans(P=0.054)emission at d 42 was observed in pigs fed NC diets supplemented with graded level of Glu.In conclusion,supplementing the reduced protein diet with Glu enhanced the growth performance in weanling pigs suggesting that supplementation of Glu can compensate the reduction of 2%CP in the basal diets.  相似文献   
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Landings in the blue crab, Portunus trituberculatus, fishery in Korean waters of the Yellow Sea have declined substantially from 11,000 t in the 1980s to 2,300 t in 2004. Blue crab habitat quality in the Yellow Sea has been degraded by anthropogenic activities including sand mining, land reclamation, and coastal pollution. Various traditional management measures have been implemented, including closed seasons during spawning and size limits, but these measures alone have been unsuccessful to conserve blue crab stocks. Consequently, a total allowable catch and a stock-rebuilding program using an ecosystem-based management approach were implemented in 2003 and 2006, respectively to rebuild blue crab stocks and restore habitats. This program involved assessment of both blue crab stock status and trammel-net fishery impacts at an ecosystem-level using an ecosystem-based fisheries assessment method ( [Zhang et al., 2009] and [Zhang et al., 2010]), which considered fishery data from catch and effort time-series, crab population biology, and ecosystem characteristics, including habitats and environmental conditions. Recent (2008) management status indices have shown significant positive change compared to conditions in 2000 with respect to sustainability of the stock and fishery and with regards to biodiversity and ecosystem habitat quality.  相似文献   
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