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291.
Craig B. Faulds Dario Zanichelli Valerie F. Crepin Ian F. Connerton Nathalie Juge Mahalingeshwara K. Bhat Keith W. Waldron 《Journal of Cereal Science》2003,38(3):281-288
Representatives of three types of feruloyl esterases were examined for their ability to release mono- and di-meric ferulic acid from water-extractable and water-unextractable cereal cell wall material, either alone or in the presence of a family 10 or family 11 xylanase. A type-C feruloyl esterase from Talaromyces stipitatus (TsFaeC) released 100% of the ferulic acid from water-extractable wheat endosperm arabinoxylan when acting in combination with a xylanase from Trichoderma longibrachiatum. The type-A esterase from Aspergillus niger, AnFaeA, was most effective in releasing ferulic acid from wheat bran and brewers' spent grain, with over 50% of the available ferulic acid being released from wheat bran in the presence of a xylanase from Bacillus subtilis. In general, family 11 xylanases were the preferred synergistic partners with feruloyl esterases for the release of ferulic acid, while family 10 xylanases were preferred for the liberation of diferulic acid, with only the 5,5′ form being released by the action of AnFaeA alone. This suggests that ferulic acid may be located in regions of low substitution on arabinoxylans while the 5,5′ diferulate moiety is located in more branched regions of the xylan chain. 相似文献
292.
293.
Elsburgh O. Clarke III Craig A. Harms J. McHugh Law James R. Flowers Valerie N. Williams Brad D. Ring 《Journal of aquatic animal health》2013,25(4):251-257
Abstract An aquaculture research facility experienced high mortality rates in white bass Morone chrysops associated with a monogenean infestation of the gills, but not in striped bass Morone saxatilis in the same facility. All mortalities had pale gills. Monogeneans, identified as Gamacallum macroura (MacCallum and MacCallum 1913) Unnithan 1971, were found on the gills. Pale-gilled and healthy white bass were selected with no particular attention to condition for venipuncture and euthanasia for postmortem examination, including parasite counts from gills. The median packed cell volume (PCV) of fish with gill pallor was 12.5% (range 9–37%) while PVC of fish with more normal color was 30% (27–33%). Association between the PCV and gill pallor score was statistically significant, as was the association between PCV and the number of monogeneans found on the gills of each fish. Median estimated white blood cell count of fish with gill pallor, at 12.05 × 103/μL (range 3.8–24.7), was significantly lower than of apparently healthy fish: 24.7 × 103/μL (17.3–31.5). Histopathology of the gill arches of pale-gilled fish revealed multifocal moderate to severe branchitis, focal areas of dilated hyperplastic lamellae occluded by fibrin, and monogeneans attached to the lamellae. Fish that were apparently healthy had grossly similar histologic lesions, but at lower frequency and severity. Received May 27, 2011; accepted July 12, 2012 相似文献
294.
Acid phosphomonoesterase (APM) (E.C. 3.1.3.2) in soil is either of plant‐root or microbial origin. Each of these sources may be dominant in certain ecosystems. Generally, extracellular APM in soil has been reported. However, the lack of suitable methods limits investigations of APM in soil. Root‐derived APM comes from intact plant roots, root exudates, root apoplastic sap, root extracts, or mycorrhizal fungi. The significance of these sources of APM is discussed in this review being the highest in intact roots or root extracts, and within wall‐ and membrane‐bound fraction of mycorrhizal fungi. Evaluation of the location of APM has been based on extraction of fractions of APM with different types of extractants. The suitability of individual extractants and lack of these procedures as well as the need to search for other suitable solutions to increase extraction efficiency, minimalize extraction of inhibitors and solubilization of organic compounds are discussed. As APM derived from roots and soil microorganisms show different kinetic properties, and differ in their response to environmental factors, determination of the significance of root and microbial APM within ecosystems requires further research aimed at evaluating the response of P transformation to climatic and other environmental changes. 相似文献
295.
296.
Wang X Wu YC Fadok VA Lee MC Gengyo-Ando K Cheng LC Ledwich D Hsu PK Chen JY Chou BK Henson P Mitani S Xue D 《Science (New York, N.Y.)》2003,302(5650):1563-1566
During apoptosis, phosphatidylserine, which is normally restricted to the inner leaflet of the plasma membrane, is exposed on the surface of apoptotic cells and has been suggested to act as an "eat-me" signal to trigger phagocytosis. It is unclear how phagocytes recognize phosphatidylserine. Recently, a putative phosphatidylserine receptor (PSR) was identified and proposed to mediate recognition of phosphatidylserine and phagocytosis. We report that psr-1, the Caenorhabditis elegans homolog of PSR, is important for cell corpse engulfment. In vitro PSR-1 binds preferentially phosphatidylserine or cells with exposed phosphatidylserine. In C. elegans, PSR-1 acts in the same cell corpse engulfment pathway mediated by intracellular signaling molecules CED-2 (homologous to the human CrkII protein), CED-5 (DOCK180), CED-10 (Rac GTPase), and CED-12 (ELMO), possibly through direct interaction with CED-5 and CED-12. Our findings suggest that PSR-1 is likely an upstream receptor for the signaling pathway containing CED-2, CED-5, CED-10, and CED-12 proteins and plays an important role in recognizing phosphatidylserine during phagocytosis. 相似文献
297.
Pasquet V Morisset P Ihammouine S Chepied A Aumailley L Berard JB Serive B Kaas R Lanneluc I Thiery V Lafferriere M Piot JM Patrice T Cadoret JP Picot L 《Marine drugs》2011,9(5):819-831
Dunaliella tertiolecta (DT) was chemically investigated to isolate molecules inhibiting cancer cell proliferation and inducing apoptosis in vitro. The potency to inhibit cell growth was used for the bio-guided fractionation and isolation of active compounds using chromatographic techniques. The DT dichloromethane extract exhibited a strong anti-proliferative activity on MCF-7 and LNCaP cells, and was further fractionated and sub-fractionated by RP-HPLC. High resolution mass spectrometry and spectrophotometric analysis unequivocally identified violaxanthin as the most antiproliferative molecule present in DT DCM extract. Violaxanthin purified from DT induced MCF-7 dose-dependent growth inhibition in continuous and discontinuous treatments, at concentrations as low as 0.1 μg·mL−1 (0.17 μM). Phosphatidylserine exposure, typical of early apoptosis, was observed after 48 h treatment at 8 μg·mL−1 (13.3 μM) but no DNA fragmentation, characteristic of late apoptosis steps, could be detected even after 72 h treatment at 40 μg·mL−1 (66.7 μM). Taken together, our results demonstrate the strong antiproliferative activity of violaxanthin on one human mammary cancer cell line, and suggest that studying the pharmacology of violaxanthin and pharmacomodulated derivatives on cancer cells may allow potent antiproliferative drugs to be obtained. 相似文献
298.
299.
Joyce Van Donkersgoed Valerie Bohaychuk Thomas Besser Xin-Ming Song Bruce Wagner Dale Hancock David Renter David Dargatz 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(2):166-172
The occurrence of generic Escherichia coli, E. coli O157, Salmonella, and Campylobacter in cattle manure, beef carcasses, catch basin water, and soils receiving manure application was determined in 21 Alberta feedlots. In cattle manure, generic E. coli (98%, 2069/2100) and Campylobacter (76%, 1590/2100) were frequently detected; E. coli O157 (7%, 143/2100) and Salmonella (1%, 20/2100) were less frequently detected. Samples from beef carcasses in the cooler following Hazard Analysis Critical Control Point interventions yielded only 1 isolate each of generic E. coli and Campylobacter (1/1653) and no Salmonella (0/1653). Catch basin water specimens were positive for generic E. coli in both the spring (62%, 13/21) and the fall (52%, 11/21). Other bacteria were detected only in the spring water specimens, including E. coli O157 (29%, 6/21), Salmonella (5%, 1/21), and Campylobacter (52%, 11/21). Generic E. coli was frequently isolated from soil specimens (30%, 27/88), but E. coli O157 was not found in soil samples obtained in the spring and was only occasionally detected in the fall samples (9%, 3/32). Salmonella were occasionally found in the soil specimens collected in the spring (3%, 2/56), but not in the fall season (0/32). Campylobacter jejuni was frequent in cattle manure (66%, 1070/1623), but rare in carcass and environmental samples. E. coli O157 and Salmonella were rarely detected in cattle or the environment. Generic E. coli and Salmonella were rarely detected on carcasses. 相似文献
300.
Valerie Sentek Andre Velescu Wolfgang Wilcke Catarina Henke Nils Peters Gerd Welp Wulf Amelung 《Soil Use and Management》2023,39(4):1477-1490
The use of urea as nitrogen (N) fertilizer in agriculture needs to consider environmental, economic and resource conservation aspects because of low N-use efficiency (NUE). Polymer-coated urea (PCU) offers an effective way to improve the NUE of urea and to reduce its environmental trade-offs. However, we lack information on the impact of climate and soil properties on N release from PCU. Therefore, this study was performed to quantify the effects of soil texture, moisture and temperature on the release kinetics of N from PCU. We designed a test system for soil incubation experiments and investigated three fertilizers with different release patterns, five topsoils, three moisture levels and two temperatures over 48 days. We analysed the concentrations of inorganic N ( and ) in the soil and estimated N release rates using the unified Richards model. Soil texture did not change the N release patterns, but release rates varied significantly among the investigated soils. Changes in soil moisture for a given soil had no effect on N release from PCU and urea when fertilizers were incorporated into the soil at conditions supportive of crop growth. Lowering soil temperatures, however, decreased N release rates from PCU by 16%–49% but only in silt loam and not in sandy loam. We conclude that PCU improves the N residence time in soil, but predictions on N release from PCU must be adapted to the prevailing environmental conditions and cannot be generalized across differently textured soils. 相似文献