Identification of Four New agr Quorum Sensing-Interfering Cyclodepsipeptides from a Marine Photobacterium     

Louise Kjaerulff  Anita Nielsen  Maria Mansson  Lone Gram  Thomas O. Larsen  Hanne Ingmer  Charlotte H. Gotfredsen 《Marine drugs》2013,11(12):5051-5062

During our search for new natural products from the marine environment, we discovered a wide range of cyclic peptides from a marine Photobacterium, closely related to P. halotolerans. The chemical fingerprint of the bacterium showed primarily non-ribosomal peptide synthetase (NRPS)-like compounds, including the known pyrrothine antibiotic holomycin and a wide range of peptides, from diketopiperazines to cyclodepsipeptides of 500–900 Da. Purification of components from the pellet fraction led to the isolation and structure elucidation of four new cyclodepsipeptides, ngercheumicin F, G, H, and I. The ngercheumicins interfered with expression of virulence genes known to be controlled by the agr quorum sensing system of Staphylococcus aureus, although to a lesser extent than the previously described solonamides from the same strain of Photobacterium.  相似文献   

Models to quantify excretion of dry matter,nitrogen, phosphorus and carbon in growing pigs fed regional diets     

Henry J?rgensen  Trakarn Prapaspongsa  Van Thi Khanh Vu  Hanne Damgaard Poulsen 《畜牧与生物技术杂志(英文版)》2013,4(1):42

Modern pig production contributes to many environmental problems that relate to manure, especially in areas with highly intensive production systems and in regions like Asia where the regulative control is not effective. Therefore, the objective of this study was to use three different pig diets varying in dietary protein, fibre and fat as representative for Danish (DK), Thai (TH) and Vietnamese (VN) pig production to develop and evaluate different approaches to predict/calculate excretion from growing pigs in comparison with the experimentally determined values.Nine female growing pigs were used in a digestibility and balance experiment. Excretion of dry matter (DM), nitrogen (N), phosphorus (P) and carbon (C) of the experimental diets were determined.Due to the highest dietary fibre content, VN had the lowest digestibility of N, P and C (73, 49, and 73%, respectively) compared with the DK and TH pig diets. From the known diet composition using standard table values on chemical and nutrient digestibly, high accuracy (bias) and low variation was found and the results could be used for prediction on chemical composition and excretion in faeces and urine in growing pigs. Calculation based on standard values regarding nutrient retention in the pig body as used in the Danish manure normative system (DMNS) showed likewise to be quite useful for quantifying the total excretion of N and P.Overall, the results demonstrate that simple models that require cheap and normally available information on dietary nutrients can give useful information on nutrient excretion in growing pigs.  相似文献   

Quality of sour cherry juice of different clones and cultivars (Prunus cerasus L.) determined by a combined sensory and NMR spectroscopic approach     

Clausen MR  Pedersen BH  Bertram HC  Kidmose U 《Journal of agricultural and food chemistry》2011,59(22):12124-12130

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NMR-based metabolomics reveals that conjugated double bond content and lipid storage efficiency in HepG2 cells are affected by fatty acid cis/trans configuration and chain length     

Najbjerg H  Young JF  Bertram HC 《Journal of agricultural and food chemistry》2011,59(16):8994-9000

In the present study the metabolic response to various fatty acids was investigated in HepG2 cells by using a (1)H NMR-based approach. To elucidate the effect of cis/trans configuration, the cells were exposed to either oleic acid (C18:1 cis-9), elaidic acid (C18:1 trans-9), vaccenic acid (C18:1 trans-11), linoleic acid (C18:2), or palmitic acid (C16:0), and multivariate data analysis revealed a strong effect of fatty acid on the lipophilic metabolite fraction. Inspection of the spectra revealed that the difference between the observed responses could be ascribed to the appearance of resonances from conjugated double bonds (5.65, 5.94, and 6.28 ppm) in cells exposed to vaccenic acid, revealing that vaccenic acid upon uptake by the HepG2 cells is converted into a conjugated fatty acid. Upon exposure of the HepG2 cells to either butyric acid (C4:0), caproic acid (C6:0), lauric acid (C12:0), myristic acid (C14:0), or palmitic acid (C16:0), an effect of fatty acid length was also evident, and data indicated that short-chain fatty acids (C4-C6) are immediately converted, whereas medium-long-chain fatty acids (C12-16) are incorporated into triglycerides and deposited in the cells. In conclusion, the present study demonstrates that (1)H NMR spectroscopy is a useful method for studying the uptake of fatty acids in in vitro cells.  相似文献   

Spin selectivity in electron transmission through self-assembled monolayers of double-stranded DNA     

Göhler B  Hamelbeck V  Markus TZ  Kettner M  Hanne GF  Vager Z  Naaman R  Zacharias H 《Science (New York, N.Y.)》2011,331(6019):894-897

In electron-transfer processes, spin effects normally are seen either in magnetic materials or in systems containing heavy atoms that facilitate spin-orbit coupling. We report spin-selective transmission of electrons through self-assembled monolayers of double-stranded DNA on gold. By directly measuring the spin of the transmitted electrons with a Mott polarimeter, we found spin polarizations exceeding 60% at room temperature. The spin-polarized photoelectrons were observed even when the photoelectrons were generated with unpolarized light. The observed spin selectivity at room temperature was extremely high as compared with other known spin filters. The spin filtration efficiency depended on the length of the DNA in the monolayer and its organization.  相似文献   

Complementary resource use in intercropped faba bean and cabbage by increased root growth and nitrogen use in organic production     

Sindhuja Shanmugam  Margita Hefner  Jeanett S. Pelck  Rodrigo Labouriau  Hanne L. Kristensen 《Soil Use and Management》2022,38(1):729-740

Intercropping can improve yield and nitrogen use efficiency in organic vegetable production by pairing crops with complementary resource use. An intercrop field experiment was conducted to determine yield, root growth and nitrogen (N) dynamics using faba bean (Vicia faba L.) grown as a vegetable and pointed cabbage (Brassica oleracea var. capitata cv. conica). Both crops were grown in monocropping (MC) and intercropping systems (IC). Minirhizotrons were used to measure root growth. Yield of pointed cabbage per metre row was 28% higher under the IC system than under MC, whereas faba bean yield as fresh seeds did not differ. The land equivalent ratio was 1.06, showing that improved yield under IC resulted from efficient land resource use. Even though MC cabbage had the highest aboveground biomass, total N accumulation was higher under IC and MC faba bean systems. Both root frequency and intensity were greater under IC faba bean rows compared with MC faba bean because of the presence of cabbage roots in faba bean rows. Monocropped cabbage had the highest root intensity and the lowest amount of soil mineral N in the 0–1.5 m depth after harvest. Monocropped cabbage was efficient in assimilating N, whereas MC faba bean was efficient in exporting N as harvestable yield. The nitrogen use efficiency using the IC system (75%) was higher than growing faba bean (44%) and cabbage (65%) alone. Thus, faba bean as an intercrop in organic cabbage production systems improves land and N use efficiency by complementary root growth.  相似文献   

Strategies for high nitrogen production and fertilizer value of plant-based fertilizers     

Mariane Lynge  Hanne Lakkenborg Kristensen  Kai Grevsen  Jorn Nygaard Sorensen 《植物养料与土壤学杂志》2023,186(1):105-115

Background

Organic vegetable production has a demand for alternative fertilizers to replace fertilizers from sources that are not organic, that is, typically animal-based ones from conventional farming.

Aims

The aim of this study was to develop production strategies of plant-based fertilizers to maximize cumulative nitrogen (N) production (equal to N yield by green manure crops), while maintaining a low carbon-to-nitrogen (C:N) ratio, and to test the fertilizer value in organic vegetable production.

Methods

The plant-based fertilizers consisted of the perennial green manure crops—alfalfa, white clover, red clover, and a mixture of red clover and ryegrass—and the annual green-manure crops—broad bean, lupine, and pea. The crops were cut several times at different developmental stages. The harvested crops were used fresh or pelleted as fertilizers for field-grown white cabbage and leek. The fertilizer value was tested with respect to biomass, N offtake, N recovery, and soil mineral N (N_min). Poultry manure and an unfertilized treatment were used as controls.

Results

The cumulative N production of the perennial green manure crops ranged from 300 to 640 kg N ha^–1 year^–1 when cut two to five times. The highest productions occurred at early and intermediate developmental stages, when cut three to four times. Annual green manure crops produced 110–320 kg N ha^–1 year^–1, since repeated cutting was restricted. The C:N ratio of the green manure crops was 8.5–20.5, and increased with developmental stage. The fertilizer value of green manure, as measured in white cabbage and leek, was comparable to animal-based manure on the condition that the C:N ratio was low (<18). N recovery was 20%–49% for green manure and 29%–42% for poultry manure. A positive correlation was detected between soil N_min and vegetable N offtake shortly after incorporating the green manure crops, indicating synchrony between N release and crop demand.

Conclusions

Plant-based fertilizers represent highly productive and efficient fertilizers that can substitute conventional animal-based fertilizers in organic vegetable production.  相似文献   

Forest sector modeling     

Hanne K. Sjølie  Birger Solberg 《Scandinavian Journal of Forest Research》2015,30(1):1-2

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Outbreak of acute larval cyathostominosis – A “perfect storm” of inflammation and dysbiosis     

Nicola Walshe  Grace Mulcahy  Fiona Crispie  Raul Cabrera-Rubio  Paul Cotter  Hanne Jahns  Vivienne Duggan 《Equine veterinary journal》2021,53(4):727-739

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Relationship between meat structure, water mobility, and distribution: a low-field nuclear magnetic resonance study   总被引：5，自引：0，他引：5  

Bertram HC  Purslow PP  Andersen HJ 《Journal of agricultural and food chemistry》2002,50(4):824-829

Nuclear magnetic resonance (NMR) measurements were carried out on pork longissimus muscle, which pre rigor had been manipulated to various muscle lengths, to investigate the relationship between the microstructure of meat and the NMR T(2) relaxation. Distributed exponential analysis of the NMR T(2) relaxation data revealed the existence of three distinct water populations: T(2b), T(21), and T(22). A high, significant correlation was found between the T(21) time constant and the sarcomere length (r = 0.84) and calculated ration of myofilament lattice volume in the I-band and A-band regions, respectively (r = 0.84), considering sigmoid relationships. The result implies that the T(21) time constant mainly is determined by the structure of the myofilament lattice and so strongly supports a previously proposed theory that the T(21) population corresponds to water located within a highly organized myofibrillar protein matrix including actin and myosin filament structures. A high correlation was also found between the T(22) population and the water-holding capacity (WHC) (r = 0.76), which suggests that the WHC is mainly determined by the amount of loosely bound extramyofibrillar water. However, the correlation between NMR T(2) parameters and WHC was further increased (r = 0.84) by including the T(21) time constant in the correlation analysis. This implies that the formation of drip loss is an ongoing process involving the transfer of water from myofibrils to the extracellular space and is affected by structural features at several levels of organization within the muscle tissue. This study demonstrates the advantages of NMR T(2) relaxation as an effective technique for obtaining further understanding of the relationship between the microstructure of meat, its WHC, water mobility, and water distribution.  相似文献