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When Chlamydomonas enzymes that convert glutamate to delta-aminolevulinic acid are separated into three fractions, one of the fractions contains RNA, and the RNA moiety is needed for the enzyme activity. 相似文献
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Growth of a nonpathogenic E. coli strain (K12- MG1655, ATCC 700926) in aerated and nonaerated compost teas containing molasses, kelp and carrot juice was examined. Teas were prepared using four different compost types that had undetectable levels of indigenous E. coli. Three of the composts were produced by turn pile windrow composting method using dairy, swine and horse manure as feedstock, while the fourth, a vermicompost, was produced by feeding separated dairy solids to worms Eisenia feotida. Molasses and kelp enhanced the growth of E. coli in inoculated teas and the E. coli density was positively correlated with nutrient concentrations ranging from 0.1 to 8.0 g/L. Irrespective of the presence of molasses and kelp, E. coli was not detected in noninoculated teas. Even though E. coli is a facultative anaerobe, its growth was significantly higher in nonaerated teas than in aerated teas. Without aeration, dissolved oxygen in teas declined rapidly and fell below 0.1 mg/L within 20 h, whereas continuous aeration at 0.8 L/min maintained an aerobic condition (> 5 mg/L dissolved oxygen) in teas during the 48 h brewing period. The pH values of nonaerated teas were significantly lower than those of aerated teas and were always slightly acidic. E. coli growth in different compost types was significantly different. The density of E. coli was lowest in teas made with vermicompost and highest in teas made with swine manure compost. E. coli proliferations in both aerated and nonaerated swine manure compost teas were inhibited by carrot juice. Carrot juice lowered dissolved oxygen in aerated teas. The total bacterial densities in noninoculated compost teas were not reduced by carrot juice. 相似文献
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Ratnasooriya WD Lelwala LH Kannangara KN Sandanayaka SD Ediriweera ER 《Fitoterapia》2006,77(4):331-332
An aqueous bark extract of Vateria copallifera showed marked sedative activity, which supports the therapeutic effects claimed by Sri Lankan traditional physicians. 相似文献
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1. A diet with addition to normal barley of malt from transgenic barley expressing a protein engineered, thermotolerant Bacillus (1,3-1,4)-beta-glucanase during germination has previously been demonstrated to provide a broiler chicken weight gain comparable to maize diets. It also reduced dramatically the number of birds with adhering sticky droppings, but did not entirely eliminate sticky droppings. One of the objectives of the broiler chicken trials reported here was to determine if higher concentrations of transgenic malt could alleviate the sticky droppings. 2. Another aim was to investigate the feasibility of using mature transgenic grain containing the thermotolerant (1,3-1,4)-beta-glucanase as feed addition and to compare diets containing transgenic grain to a diet with the recommended amount of a commercial beta-glucanase-based product. 3. Inclusion of 75 or 151 g/kg transgenic malt containing 4.7 or 98 mg/kg thermotolerant (1,3-1,4)-beta-glucanase with 545 or 469 g/kg non-transgenic barley instead of maize yielded a weight gain in Cornish Cross broiler chickens indistinguishable from presently used maize diets. The gene encoding the enzyme is expressed in the aleurone with a barley alpha-amylase gene promoter and the enzyme is synthesised with a signal peptide for secretion into the endosperm of the malting grain. 4. Equal weight gain was achieved, when the feed included 39 g/kg transgenic barley grain [containing 66 mg/kg thermotolerant (1,3-1,4)-beta-glucanase] and 581 g/kg non-transgenic barley instead of maize. In this case, the gene encoding the enzyme has been expressed with the D-hordein gene (Hor3-1) promoter during grain maturation. The enzyme is synthesised as a precursor with a signal peptide for transport through the endoplasmic reticulum and targeted into the storage vacuoles. Deposition of the enzyme in the prolamin storage protein bodies of the endosperm protects it from degradation during the programmed cell death of the endosperm in the final stages of grain maturation and provides extraordinary heat stability. The large amount of highly active (1,3-1,4)-beta-glucanase in the mature grain allowed the reduction of the transgenic grain ingredient to 0.2 g/kg diet, thus making the ingredient comparable to that of the trace minerals added to standard diets. 5. A direct comparison using transgenic grain supplement at the level of 1 g/kg of feed with the standard recommended addition of the commercial enzyme preparation Avizyme 1100 at 1 g/kg yielded equal weight gain, feed consumption and feed efficiency in birds fed a barley-based diet. 6. The production of sticky droppings characteristic of broilers fed on barley diets was avoided with all 9 experimental diets and reduced to the level observed with a standard maize diet by supplementation with transgenic barley. 7. The excellent growth and normal survival of the 400 broilers tested on barley diets supplemented with transgenic grain or malt showed the grain and malt not to be toxic. 8. The barley feed with added transgenic grain or malt containing thermotolerant (1,3-1,4)-beta-glucanase provides an environmentally friendly alternative to enzyme additives, as it uses photosynthetic energy for production of the enzyme in the grain and thus avoids use of non-renewable energy for fermentation. The deposition of the enzyme in the protein bodies of the grain in the field makes coating procedures for stabilisation of enzyme activity superfluous. 9. Barley feed with the small amount of transgenic grain as additive to normal barley provides an alternative for broiler feed in areas where grain maize cannot be grown for climatic reasons or because of unsuitable soil and thus has to be imported. 相似文献
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The agar-film method was used to assess fungal biomass and standing crop in several analogous decomposition stages of two leaf species (the fast decomposing Michelia nilagirica and the slow decomposing Semecarpus coriaceae), both from an upper montane rainforest in Sri Lanka. At all decomposition stages the fungal biomass on Michelia litter was significantly higher (P<0.001) than for Semecarpus and had developed much more rapidly (17.04 mg g−1 at the first decomposition stage compared with 4.39 mg g−1 for Semecarpus). These figures are considerably higher than those for a cool temperate deciduous forest, but when the data are given as fungal biomass per area the reverse is true. Data are given on the contribution of different hyphal types showing a trend for change (hyaline to dark hyphae) during the course of decomposition. The mass of dead hyphae is considerably lower than data from temperate forests. Data on immobilization of C and of plant nutrients (N, P, K, Ca, Mg and Na) are provided plus hyphal nutrient contents expressed as % of total contents in the leaf litter. These data are comparable to those from temperate forests. 相似文献
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Three windrows were constructed from a mixture of horse manure and soiled bedding collected from four equestrian centres in the Fraser Valley, British Columbia, where stables were bedded with hemlock, spruce, and fir wood shavings. Composting was accomplished by turning the windrows twice a week during the first four weeks and once a week for eight additional weeks. At the end of 12- week composting period, windrows were combined and allowed to cure for three months. The cured compost was tested for the ability to promote cucumber (cv Enigma) seedling growth, supply micronutrients, and suppress mycelial growth of plant pathogen Fusarium oxysporum f.sp. radicis cucumerinum (FORC). The heights and dry weights of cucumber seedlings grown in 20% compost in sawdust were significantly greater than those grown in sawdust alone. When fed with nutrient solutions lacking micronutrients, seedling grown in 20% compost gave significantly greater height, dry weight, and chlorophyll concentrations compared to seedlings grown in sawdust alone. The analysis of extractable micronutrients indicated that manganese, followed by zinc and boron, were the predominant micronutrients in horse manure compost. Both iron and molybdenum concentrations were present in less than one ppm and copper was present just above one ppm. There was a significant correlation (r2 = 0.83) between in vivo chlorophyll measurements by SPAD-502 chlorophyll meter and the in vitro chlorophyll measurement by spectrophotometer. Thus in vivo measurements of SPAD-502 chlorophyll meter can be used to assess nutrient availability from compost to cucumber seedlings. Horse manure compost also contained bacteria that suppressed mycelial growth of FORC. 相似文献
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Edirisinghe I Burton-Freeman B Varelis P Kappagoda T 《Journal of agricultural and food chemistry》2008,56(20):9383-9390
Polyphenolic compounds are vasodilators and help to lower the risk of cardiovascular diseases. We hypothesized that a freeze-dried strawberry powder that is rich in polyphenolic compounds would cause an endothelium-dependent relaxation (EDR) through the activation of phosphatidylinositol-3 (PI3)-kinase/protein kinase B (Akt) in rabbit aorta. The powder was prepared by freeze drying a homogenate of ripe California strawberry fruits. An aqueous extract of strawberry powder was applied to rabbit aortic rings suspended in organ baths containing Krebs-Henseleit buffer maintained at 37 degrees C. In aortic rings precontacted with norepinephrine, the extract produced a dose-dependent relaxation. The maximum relaxations elicited by the extract (73.1 +/- 1.0%) were similar to those elicited by acetylcholine (68.2 +/- 1.5%) ( n = 14 for each). The relaxation by strawberry extract was abolished by removal of the endothelium and by prior incubation with N omega-nitro- l-arginine methyl ester hydrochloride (L-NAME), confirming the essential role of endothelial nitric oxide synthase (eNOS). The responses to the strawberry were also abolished by incubation with wortmannin and LY294002, which are inhibitors of PI3 kinase. Using immunoblotting, we also demonstrated that the strawberry extract induced the phosphorylation of both Akt and eNOS in human umbilical vein endothelial cells (HUVECs) via PI3 kinase/Akt pathway. Taken together, our novel findings suggest that the EDR induced by the strawberry extract was mediated by activation of the PI3 kinase/Akt signaling pathway, resulting in phosphorylation of eNOS. 相似文献
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