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1.
Klaus Fischer Karlheinz Blay Jarmila Kotalik Peter Riemschneider Dietmar Klotz Antonius Kettrup 《植物养料与土壤学杂志》1997,160(4):511-518
Extraction of a copper contaminated soil material by the percolation of an amino acid containing residue hydrolysate. 2. Time course of amino acid elution and input/output balance of amino acids During 16 days an amino acid containing blood meal hydrolysate (amino acid concentration: 188 mMol·L?1) was percolated through a column packed soil material (soil content per column: 4.1 kg dry weight, four parallels). The copper contaminated material (soil type: Typic Udifluvent, soil texture: sandy loam, loamy sand) was sampled from an area formerly used for cultivation of hop (Humulus lupus). Besides the investigation of the copper liberation the experiments aimed to determine the elution dynamic and input/output balance of amino acids (time span for amino acids balance 14 days). In total 11.7 L of hydrolysate, containing 2.2 Mol of amino acids, were introduced into each column. The mean amino acid output with the column effluent was 1.13 Mol. This corresponds to an elution degree of 51.2%, related to the sum of applicated amino acids, and to a mean substance specific elution degree of 48.4% reflecting the elution of 15 compounds. The substance specific elution ranged from 9.6% (serine) to 75.5% (valine). The highest concentrations of serine and threonine were determined in the effluents after two days, whereas the histidine concentration was highest at the last sampling. The differences in the percolation properties of the amino acids are discussed in terms of important retention and elimination processes (biodegradation, ad-/desorption, intercalation). 相似文献
2.
Dorfner R Ferge T Kettrup A Zimmermann R Yeretzian C 《Journal of agricultural and food chemistry》2003,51(19):5768-5773
The formation of 4-vinylguaiacol, guaiacol, and phenol during coffee roasting was monitored in real-time, using resonance enhanced multiphoton ionization and time-of-flight mass spectrometry. A model is proposed, based on two connected reaction channels. One channel, termed the "low activation energy" channel, consists of ester hydrolysis of 5-FQA followed by decarboxylation of the ferulic acid to form 4-vinylguaiacol, and finally polymerization at the vinyl group to form partly insoluble polymers (coffee melanoidins). The second "high activation energy" channel opens up once the beans have reached higher temperatures. It leads to formation of guaiacol, via oxidation of 4-vinylguaiacol, and subsequently to phenol and other phenolic VOCs. This work aims at developing strategies to modify the composition of coffee flavor compounds based on the time-temperature history during roasting. 相似文献
3.
Resistance to a number of inhibitors of sterol C-14 demethylation, (clotrimazole, imazalil, miconazole, fenarimol, nuarimol and triadimefon), as well as resistance to inhibitors of sterol C-14(15) double bond reduction, (tridemorph and fenpropi-morph), was readily induced in Ustilago maydis. Resistant mutants were obtained after mutagenic treatment by ultraviolet irradiation, or by treatment with 1-methyl-3-nitro-1-nitrosoguanidine, of sporidia of the wild-type strain, followed by selection in the presence of the toxicant. The level of resistance of these mutants varied appreciably. Although not always reciprocal, cross-resistance to fungicides which inhibit ergosterol biosynthesis (EBIs) appeared to be present in most cases. Several of the U. maydis mutants which were resistant to inhibitors of sterol C-14 demethylation lacked cross-resistance to tridemorph and fenpropimorph, or displayed increased sensitivity to fenpropimorph (negatively correlated cross-resistance). Cross-resistance between EBIs and the antimicrobial agents climbazole and lombazole was also established. It is suggested that fungal mutants that possess a resistance mechanism based on a deficiency in sterol C-14 demethylation or sterol C-14(15) double bond reduction, have a greatly reduced chance of survival. 相似文献
4.
Isolates of Erysiphe graminis f.sp. tritici with wild-type or reduced sensitivity to fenpropimorph were similar in sterol composition, viz. ergosta-5,24(28)-dienol (±90%) and episterol (±10%). Following treatment with fenpropimorph, the relative content of episterol increased in conidia of all isolates tested, while that of ergosta-5,24(28)-dienol decreased. These results suggest that fenpropimorph, under the test conditions used, does not inhibit activity of sterol Δ14-reductase or Δ8→Δ7-isomerase but probably interferes with the final part of the demethyl sterol synthesis. However, modifications in this part of the pathway are probably not responsible for the decreased sensitivity of the pathogen to the fungicide. © 1998 SCI. 相似文献
5.
Diogenes Dezen Franciscus Antonius Maria Rijsewijk Thais Fumaco Teixeira Carine Lidiane Holz Samuel Paulo Cibulski Ana Cláudia Franco Odir Antonio Dellagostin Paulo M. Roehe 《Research in veterinary science》2010,88(3):436-440
Multiply-primed rolling-circle amplification (MPRCA) was used to amplify porcine circovirus type 2 (PCV2) genomes isolated from tissues of pigs with signs of post-weaning multisystemic wasting syndrome (PMWS). Two of the amplified PCV2 genomes were cloned in prokaryotic plasmids and sequenced. Both were nearly identical (1767 nt) except for one silent substitution in the region coding for the capsid protein (ORF2). In addition, they showed high nucleotide sequence similarity with PCV2 isolates from others countries (93–99%). To investigate whether the MPRCA amplified PCV2 genomes could be used to produce infectious virus, the cloned genomes were isolated from the plasmids, recircularized and used for transfection in PK-15 cells. This procedure led to the production of infectious virus to titres up to 105.55 TCID50/mL. It was concluded that MPRCA is a useful tool to amplify PCV2 genomes aiming at sequencing and virus isolation strategies, where particularly useful is the fact that it allows straightforward construction of PCV2 infectious clones from amplified genomes. However, it was less sensitive than PCR for diagnostic purposes. 相似文献
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7.
Nourrddine Chafik Mohammed Mansour Btissam Elamrani Karl‐Werner Schramm Antonius Kettrup M Khalid Elamrani 《Pest management science》2001,57(6):527-530
The photochemical fate of the herbicide triflusulfuron‐methyl in aqueous solution under UV light (λ > 290 nm) was investigated. Nine photoproducts were detected and tentatively identified by LC/MS and LC/MS/MS analysis. The main routes of degradation involve the cleavage and/or contraction of the sulfonylurea bridge with the elimination of sulfur dioxide, which increases the acidity of the reaction medium. On the basis of the results obtained a photodegradation pathway is proposed. © 2001 Society of Chemical Industry 相似文献
8.
Antonius G. T. SCHUT Emily C. COOLEDGE Marc MORAINE Gerrie W. J. VAN DE VEN Davey L. JONES David R. CHADWICK 《农业科学与工程前沿(英文版)》2021,8(1):111
9.
Pig performance increases with the addition of dl-methionine and l-lysine to ensiled cassava leaf protein diets 总被引:1,自引:0,他引:1
Two studies were conducted to determine the impact of supplementation of diets containing ensiled cassava leaves as the main
protein source with synthetic amino acids, dl-methionine alone or with L-lysine. In study 1, a total of 40 pigs in five units, all cross-breds between Large White and Mong Cai, with an average initial
body weight of 20.5 kg were randomly assigned to four treatments consisting of a basal diet containing 45% of dry matter (DM)
from ensiled cassava leaves (ECL) and ensiled cassava root supplemented with 0%, 0.05%, 0.1% and 0.15% dl-methionine (as DM). Results showed a significantly improved performance and protein gain by extra methionine. This reduced
the feed cost by 2.6%, 7.2% and 7.5%, respectively. In study 2, there were three units and in each unit eight cross-bred (Large
White × Mong Cai) pigs with an initial body weight of 20.1 kg were randomly assigned to the four treatments. The four diets
were as follows: a basal diet containing 15% ECL (as DM) supplemented with different amounts of amino acids l-lysine and dl-methionine to the control diet. The results showed that diets with 15% of DM as ECL with supplementation of 0.2% lysine +0.1%
dl-methionine and 0.1% lysine +0.05% dl-methionine at the 20–50 kg and above 50 kg, respectively, resulted in the best performance, protein gain and lowest costs
for cross-bred (Large White × Mong Cai) pigs. Ensiled cassava leaves can be used as a protein supplement for feeding pigs
provided the diets contain additional amounts of synthetic lysine and methionine. 相似文献
10.
Wijnand B. Nimmo Antonius G. M. Willems Kees D. Joustra Arie Verloop 《Pest management science》1986,17(4):403-411
The fate of 4-chlorophenylurea in soils was studied with two preparations: one labelled with 14C in the phenyl ring and the other in the carbonyl group. The initial dose of 1 mg kg?1 decreased to 50% in about 5 weeks in aerobic sandy clay and in about 16 weeks in anaerobic hydrosoil. Soil treatment with each of the preparations resulted in the release of [14C]carbon dioxide, pointing to decarbonylation and ring opening. The fraction of non-extractable (soil-bound) radioactivity increased during incubation. Quantities of ring-14C-labelled and carbonyl-14C-labelled bound residues differed strongly in the aerobic soil but only slightly in the anaerobic hydrosoil. It is assumed that two sorts of bound residues are formed from 4-chlorophenylurea: one is fairly stable and might consist of bound 4-chloroaniline or its transformation products, whereas the other is presumed to be a degradable derivative of 4-chlorophenylurea. 相似文献