排序方式： 共有12条查询结果，搜索用时 15 毫秒
1.
2.
3.
Faouzi Lamari Khouadja Sadok Amina Bakhrouf François-Joël Gatesoupe 《Aquaculture International》2014,22(2):699-709
Lactic acid bacteria (LAB) were isolated from rotifer cultures in a marine hatchery to search for potential probiotics for marine animals. Fifteen strains were first selected among a total of 55, according to antibacterial activity against Vibrio sp. Among eight strains identified as Lactobacillus casei, four were highly adhesive, suggesting some ability for surface colonization. The other strains were identified as Lactobacillus plantarum, Lactobacillus dextrinicus, and Leuconostoc sp. To validate probiotic potential, Artemia were challenged against pathogenic Vibrio alginolyticus, with or without one of six selected LAB strains. The six strains protected Artemia against the pathogen, to some extent on condition that nutrient enrichment was provided. La. casei BR51 and X2 were preferred, as they were efficient even in the absence of nutrient supply. La. casei X2 was finally selected as candidate probiotic, due to the best growth performances of Artemia, with or without the pathogen. 相似文献
4.
Papandreou MA Kanakis CD Polissiou MG Efthimiopoulos S Cordopatis P Margarity M Lamari FN 《Journal of agricultural and food chemistry》2006,54(23):8762-8768
Crocus sativus stigmas are one of the widely known spices (saffron) and consist of unusually polar carotenoids. Alzheimer's disease is characterized pathologically by deposition of amyloid beta-peptide (Abeta) fibrils. Oxidation is thought to promote Abeta fibril formation and deposition. To identify agents inhibiting the pathogenesis of Alzheimer's disease, we examined in vitro the antioxidant properties of extract of C. sativus stigmas and its effect on Abeta(1-40) fibrillogenesis. The antioxidant properties were determined by measuring the ferric-reducing antioxidant power and Trolox-equivalent antioxidant capacity, while its effects on Abeta-aggregation and fibrillogenesis were studied by thioflavine T-based fluorescence assay and by DNA binding shift assay. The water:methanol (50:50, v/v) extract of C. sativus stigmas possesses good antioxidant properties, higher than those of tomatoes and carrots, and inhibited Abeta fibrillogenesis in a concentration and time-dependent manner. The main carotenoid constituent, trans-crocin-4, the digentibiosyl ester of crocetin, inhibited Abeta fibrillogenesis at lower concentrations than dimethylcrocetin, revealing that the action of the carotenoid is enhanced by the presence of the sugars. Our findings suggest the possible use of C. sativus stigma constituents for inhibition of aggregation and deposition of Abeta in the human brain. 相似文献
5.
ABSTRACT Pyrenophora tritici-repentis causes necrosis and chlorosis in its wheat host. Susceptibility to races 2 (necrosis) and 5 (chlorosis) of the pathogen is known to be mediated by Ptr ToxA and Ptr ToxB, respectively. Sensitivity to each toxin is controlled by a single dominant and independently inherited gene. We used sensitivity to Ptr ToxA and Ptr ToxB as two genetic markers to investigate the origin and the state of tan spot susceptibility in Canadian Western Red Spring (CWRS) wheat over a period of more than a century. Sensitivity to Ptr ToxA, the toxin produced by nearly all isolates of the pathogen collected in the past 20 years in western Canada, appears to have been present in the first major cultivar, Red Fife, grown massively in the late 1800s. Sensitivity then was transmitted unknowingly into Canadian wheat lines through extensive use of backcrossing to maintain the Marquis-Thatcher breadmaking quality. Sensitivity to Ptr ToxA, which nearly disappeared from cultivars grown in western Canada in the 1950s, was reintroduced in the 1960s and unintentionally bred into many of the present-day cultivars. Sensitivity to Ptr ToxB, a toxin rarely found in isolates from western Canada, appeared with the release of Thatcher in 1934 and was transferred to many cultivars through backcross programs. In spite of large areas planted to Ptr ToxAand Ptr ToxB-sensitive cultivars over decades, tan spot epidemics remained sporadic until the 1970s. The results of this study raise the problem of the narrowing genetic base of CWRS wheat lines and the potential for unanticipated threats from plant pathogens. The intercrossing of genetically diverse material in one Canadian wheat breeding program resulted in the release of several modern cultivars with resistance to tan spot. The absence of wild-type Ptr ToxB-producing isolates in western Canada remains unexplained, given that sensitivity to Ptr ToxB was present continuously in western Canadian cultivars grown on vast areas for more than 70 years. 相似文献
6.
7.
8.
Geromichalos GD Lamari FN Papandreou MA Trafalis DT Margarity M Papageorgiou A Sinakos Z 《Journal of agricultural and food chemistry》2012,60(24):6131-6138
Inhibitors of acetylcholine breakdown by acetylcholinesterase (AChE) constitute the main therapeutic modality for Alzheimer's disease. In the search for natural products with inhibitory action on AChE, this study investigated the activity of saffron extract and its constituents by in vitro enzymatic and molecular docking studies. Saffron has been used in traditional medicine against Alzheimer's disease. Saffron extract showed moderate AChE inhibitory activity (up to 30%), but IC(50) values of crocetin, dimethylcrocetin, and safranal were 96.33, 107.1, and 21.09 μM, respectively. Kinetic analysis showed mixed-type inhibition, which was verified by in silico docking studies. Safranal interacts only with the binding site of the AChE, but crocetin and dimethylcrocetin bind simultaneously to the catalytic and peripheral anionic sites. These results reinforce previous findings about the beneficial action of saffron against Alzheimer's disease and may be of value for the development of novel therapeutic agents based on carotenoid-based dual binding inhibitors. 相似文献
9.
10.
ABSTRACT Pyrenophora tritici-repentis, causal agent of tan spot, induces necrosis and chlorosis in its wheat host. The tan spot system conforms to the toxin model and three host-specific toxins have been identified (Ptr ToxA, Ptr ToxB, and putative Ptr ToxC). Processing of a collection of isolates, obtained in the Fertile Crescent and Caucasus regions, yielded two new virulence patterns. Isolate Az35-5 combined the virulences of races 2 and 5 and was classified in the new race 7. Isolates TS93-71B and TS93-71F had a virulence pattern that combined those of races 2, 3, and 5 and were grouped in the new race 8. Southern analysis revealed that all three isolates possessed copies of the ToxA and ToxB genes, the first time the genes were found in a common background. The production of Ptr ToxA and Ptr ToxB by the isolates was confirmed by western blotting. Virulence patterns suggested that TS93-71B and TS93-71F may also produce Ptr ToxC, even though it was not present at detectable levels in culture filtrates. The identification of races 7 and 8 complete the theoretical maximum number of races that can be differentiated by three loci in the host (2(3) = 8), assuming a one-to-one relationship. It appears that the wheat/P. tritici-repentis system is a mirror image of the classical gene-for-gene relationship. 相似文献