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1.
Fusarium toxins are secondary metabolites produced byfungi of these genera in many commodities under certain conditions. A study was carried out to investigate the co-occurrence of zearalenone (ZEN), deoxynivalenol (DON) and fumonisins (FB1 and FB2) in 52 samples of mixed-feed for poultry contaminated withFusarium verticillioides. The zearalenone and deoxynivalenol were checked using immunoaffinity column and the extraction of fumonisin was performed by strong anion exchange (SAX) solid phase column. Detection and quantification were determined by high performance liquid chromatography (HPLC). The limit of detection was 5 μg/kg for ZEN, 100 μg/kg for DON and 50 and 100 μg/kg for FB1 and FB2 respectively.Fusarium toxins were detected in 20 samples. Sixteen samples were positive for ZEN (30.7%) presenting levels that ranged from 7.4 μg/kg to 61.4 μg/kg (mean=27.0 μg/kg). 13.5% of the samples presented contaminations of DON, with levels ranging from 100.0 μg/kg to 253 μg/kg (mean=l18.07 μg/kg). FB1 was detected in 19.2% of samples, with levels ranging from 50.0 μg/kg to 110.0 μg/kg (mean=73.6 μg/kg). FB2 was not detected in any sample. In positive samples simultaneously contamination with two or three mycotoxins were detected in 9 of them (17.3%).  相似文献   

2.
A HPLC method for the determination of ergometrine, ergotamine, ergocristine, α-ergocryptine and ergocornine in cereals for animal feed and in mixed feed with high cereal content was developed. Samples were extracted under acidic conditions using a mixture of phosphoric acid and acetonitrile, the extract purified with solid phase extraction cartridges (strong cation exchange), and ergot alkaloids detected after gradient elution on a C18 column by HPLC with fluorescence detection. Detection and determination limits for each individual alkaloid were at 5 (μ/kg and 10 (μg/kg, respectively. With this method, high recovery (82–120%) and good reproducibility was achieved for wheat, rye and mixed feeds, at a sum of total determined alkaloids of < 500 (μg/kg. This method was used to analyse Bavarian feeds (n=124) over three years (2005–2007), and ergot alkaloids were detected in 91 % of the samples. The majority of positive samples had ergot alkaloid contents of < 250 μg/kg, the median alkaloid level was at 70 (μg/kg. The maximum sum of total determined alkaloids exceeded 1000 (μg/kg in wheat, triticale, rye, and mixed feeds, the highest result was obtained for mixed feed (4880 (μg/kg). Parts presented at the Feed Safety Conference, Namur, Belgium, Nov 27–28, 2007  相似文献   

3.
The authors present a new and sensitive method for the determination of T-2- und HT-2 Toxin in cereals and cereal products in the low ppb level. A representative part of the cereal sample is extracted with a mixture of methanol-water (90:10) and the extract is cleaned on the commercially available immunoaffinity column T-2test™ (IAC), eluted with methanol, derivatized by pentafluorpropionic anhydride (PFPA) and measured on a GC-ECD. The method has been successfully validated on wheat, rye and oats. The recovery rates with wheat and rye endowed on a level of 50 ppb and with 85 ppb naturally contaminated oats were 71–115% with a coefficient of variation of 5.7–19.5%. The detection limits of the method with a signal to noise level of 3:1 were 1.5–2.3 μg/kg for HT-2 and 1.1–1.7 μg/kg for T-2 toxin. Financial support: Federal Ministry of Food and Agriculture (part of the project 05HS 001 — Improvement and validation of type A trichothecene (T-2 toxin and HT-2 toxin) analysis and occurrence of these mycotoxins in food marketed in Germany)  相似文献   

4.
A method for the determination of the mycotoxin citrinin (CT) in rye, wheat and barley is described. The proposed method is based on ethyl acetate extraction, solid phase clean-up (SPE) on aminopropyl columns and reversed phase high performance liquid chromatography with fluorescence detection (RP-HPLC-FLD). The limits of detection and quantification of CT amounted to 0.6–0.9 μg/kg and 1.7– 3.3 μg/kg with mean recovery rates in the range of 77–92% (RSD 4.8–5.5%). This method can also be used for the determination of CT in red-fermented rice. Presented at the 29th Mykotoxin-Workshop, Fellbach, Germany, May 14–16, 2007  相似文献   

5.
In vitro culture establishment, shoot proliferation and ex vitro rooting responses of chokecherry (Prunus virginiana L.), `Garrington', and pincherry (P. pensylvanica L.f), `Mary Liss' and `Jumping Pound', were examined using various combinations of growth regulators. Dormant winter buds were used as explants. MSMO medium supplemented with 0.49 μM IBA and either 4.44 or 8.87 μM BA was found to be optimal for culture initiation of both species and cultivars. GA3 (28.89 μM) significantly reduced (p=0.0001) the number of successfully established cultures. BA concentrations 8.87–12.82 μM gave optimal shoot proliferation in chokecherry and 4.44 μM BA in both cultivars of pincherry. Auxin treatments were required for ex vitro rooting of approximately 10 mm long shoots in peat/perlite (1:1 v/v) mixture, at 25 °C, under mist. The best rooting (84%) was obtained with IBA/NAA (9.80/2.69 μM). A commercial rooting powder, Rootone F, containing IBA/NAA (0.057/0.067%) mixture, was also effective (75%). The ex vitro rooted plantlets did not require any additional acclimatization prior to transplanting to the regular greenhouse conditions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

6.
Light- and CO2-saturated photosynthesis of nonhardened rye (Secale cereale L. cv. Musketeer) was reduced from 18.10 to 7.17 mol O2·m–2·s–1 when leaves were transferred from 20 to 5°C for 30 min. Following cold-hardening at 5°C for ten weeks, photosynthesis recovered to 15.05 mol O2·m–2·s–1,comparable to the nonhardened rate at 20°C. Recovery of photosynthesis was associated with increases in the total activity and activation of enzymes of the photosynthetic carbon-reduction cycle and of sucrose synthesis. The total hexose-phosphate pool increase by 30% and 120% for nonhardened and cold-hardened leaves respectively when measured at 5°C. The large increase in esterified phosphate in coldhardened leaves occurred without a limitation in inorganic phosphate supply. In contrast, the much smaller increase in esterified phosphate in nonhardened leaves was associated with an inhibition of ribulose-1,5-bisphosphate carboxylase/oxygenase and sucrose-phosphate synthase activation. It is suggested that the large increases in hexose phosphates in cold-hardened leaves compensates for the higher substrate threshold concentrations needed for enzyme activation at low temperatures. High substrate concentrations could also compensate for the kinetic limitations imposed by product inhibition from the accumulation of sucrose at 5°C. Nonhardened leaves appear to be unable to compensate in this fashion due to an inadequate supply of inorganic phosphate.Abbreviations DHAP dihydroxyacetone phosphate - Fru6P fructose-6-phosphate - Fru 1,6BP fructose-1,6-bisphosphate - Fru1,6BPase fructose-1,6-bisphosphatase - Glc6P glucose-6-phosphate - PGA 3-phosphoglycerate - PPFD photosynthetic photon flux density - CH cold-hardened rye grown at 5°C - NH nonhardened rye grown at 24°C - Rubisco ribulose-1,5-bisphosphate carboxylase/oxygenase - RuBP ribulose-1,5-bisphosphate - SPS sucrose-phosphate synthase - UDPGlc uridine 5-diphosphoglucose This work was supported by operating grants from the Swedish Natural Sciences Research Council to G.Ö. and P.G.  相似文献   

7.
Forty-three peanut butter samples from Khartoum State, Sudan, were analyzed for aflatoxins (AFs, AFB1 + AFB2 + AFG1 + AFG2) using high performance liquid chromatography (HPLC) with fluorescence detection after extraction with methanol:water (8:1, v/v) and clean-up using chloroform. All samples were contaminated with AFs, with total AF levels ranging between 26.7 and 853 μg/kg, and a mean total AF level of 287 ± 200.5 μg/kg. The highest concentrations were found for AFB1, (28 positive samples, maximum 534 μg/kg), while AFG1 was most frequently detected (43 positive samples, maximum 401 μg/kg). AFB2 (42 positive samples, maximum 3.2 μg/kg) and AFG2 (4 positive samples, maximum 30 μg/kg) were also present in these samples. The mean AF contamination levels found in this study exceeded by far all international regulations concerning maximum levels for this group of toxins. From the data, it is concluded that the levels of AF contamination in peanut butter from the Kartoum area are quite alarming, and may pose serious health hazards to consumers. Therefore, an intervention strategy to manage AF in peanut butter is urgently needed.  相似文献   

8.
A total of 404 samples of commercial swine feed from Portugal feed mills were analysed by HPLC methods for the presence of mycotoxins: 277 samples of feed for fattening pigs were analysed for ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON), and 127 samples of feed for sows were analysed for ZEA and fumonisins (FB1 + FB2). Concerning feed for fattening pigs, 21 (7.6%) samples were positive for OTA, (2–6.8 μg/kg), 69 (24.9%) were positive for ZEA (5–73 μg/kg), and 47 (16.9%) were positive for DON (100–864 μg/kg). In feed for sows, the results showed 29.9% of positive samples for ZEA (5–57.7 μg/kg) and 8.7% positive samples for FB1 and FB2 (50–391.4 μg/kg). Co-occurrence of DON/ZEA was found most frequently, but simultaneous contamination with OTA/ZEA and OTA/DON was also found.  相似文献   

9.
Summary In vitro methods were applied to the only remaining plant of the Meelup Mallee (Eucalyptus phylacis), a critically endangered species from the southwest of Western Australia. Shoot explants were initiated into culture using a 1/2 MS [Murashige and Skoog basal medium (BM) for all experiments] liquid medium supplemented with 1% (w/v) activated charcoal, which was replenished twice daily, followed by transfer of explants to agar medium supplemented with 0.5 μM zeatin. Explants were cultured under low intensity lighting (PPFD of 5–10 μmol m−2s−1) to minimize blackening of tissues, and some explants were induced to produce nodular green calluses in response to BM supplemented with 5 μM thidiazuron. Nodular green calluses were induced to form adventitious shoots following transfer to medium supplemented with 0.5 μM zeatin and 1 μM gibberellic acid, A4 isomer (GA4). Development of shoots was completed on 1 μM zeatin + 0.1 μM 6-benzylaminopurine (BA) in vented culture tubes. Regenerated shoots were sequentially cultured on medium containing 0.5 μM zeatin + 0.2 μM indoleacetic acid (IAA) followed by either 0.5 μM zeatin + 1μM GA4 for shoot elongation or 1 μM zeatin + 0.5 μM IAA to optimize shoot growth. Rooted microshoots were produced after 4 weeks on 5 μM indolebutyric acid (IBA) and survived acclimatization and transfer to potting mixture.  相似文献   

10.
Huber  C.  Oberhauser  A.  Kreutzer  K. 《Plant and Soil》2002,240(1):3-11
Laboratory and field measurements of the flux of ammonia to forest floor canopies of spruce and beech stands at the Höglwald site in southern Bavaria are reported. Measurements were performed with an open chamber method. A linearity between ammonia concentration and ammonia flux from the atmosphere to the ground floor canopy was detected. Deposition of ammonia showed no saturation even at air concentrations up to 50 g NH3 m–3 air. Temperature, water content and the moss layer of the ground floor canopy had a minor influence on the deposition velocity in laboratory experiments. Deposition velocity of ammonia was higher to the spruce (1.3 cm s–1), and limed spruce ground floor canopy (1.17 cm s–1) compared to the beech stand (0.79 cm s–1). In field studies, a diurnal course of the deposition velocity was detected with highest velocities in midday and minor during night times, but not in the climatic chamber. The flux of ammonia to the ground floor canopy was estimated of app. 10 kg N ha–1 yr–1 for the soil under spruce, 9 kg N ha–1 yr–1 for the limed spruce and 6 kg N ha–1yr–1 for the soil under beech. The fluxes are interpreted as fluxes from the atmosphere to the ground canopies of the stands.  相似文献   

11.
Total DNA was extracted formSecale cereale L. cv. ‘Petkus’ and labeled with biotin-11-dUPT. Labeled rye DNA and non-labeled wheat DNA in a mixture of 1∶1 were used as a probe on chromosome preparations of Welsh triticale and Kavkaz wheat, a wheat translocation stock. Hybridization of denatured probe and chromosomes took place overnight at 37°C in the presence of 10% (w/v) dextran sulfate, 50% (v/v) formamide, 10 mM PIPES, 0.1 mMEDTA and 0.3 M NaC1. Biotin-labeled rye DNA was detected using streptavidin-horseradish peroxidase conjugate. Staining was made with diaminobenzidine tetrahydrochloride and hydrogen peroxide. Observations made on Giesma counter-stained slides indicated that the rye chromosomes in Welsh triticale and the two short arms of a pair of satellite chromosomes (1RS) in Kavkaz wheat were preferentially labeled. Hybridization signals were seen as dark brown to bluish black in color. The technique described above is simple. It does not require the isolation of a species-specific probe. Itallows rapid identification of hybrids and/or chromosome translocations in wide hybridizations.  相似文献   

12.
Fumonisins, fungal toxins found primarily in maize and produced by various Fusarium species, have been shown to cause a variety of significant adverse health effects in livestock and experimental animals, and are probable human carcinogens. Thirty-three maize samples were collected at ports from bulk shipments, which were imported into Iran from six countries during 2001–2002, and analysed by HPLC for the most abundant of the naturally occurring fumonisin analogues, namely fumonisins B1 (FB1), B2 (FB2) and B3 (FB3). Of the 33 samples, 21 (64%) were found to contain FB1 (58–512 μg/kg) at levels above 10 μg/kg. The frequency of FB1 found in maize samples imported from Uruguay and Canada was 75%, followed by China and Argentina (67%), USA (60%), and Brazil (50%). The average FB1 level was 266 and 169 μg/kg for positive and all samples, respectively. Medians were 250 and 146 μg/kg for positive and all samples, respectively. FB2 levels ranged from not detected (<10 μg/kg) to 53 μg/kg, whereas no sample had an FB3 level above the detection level (10 μg/kg). This is the first report of fumonisin contamination of imported maize in Iran. Although, the level of all detected fumonisins were below the Iranian and FDA tolerance levels for foods and feeds, It is necessary to maintain the strict rules to ensure continued safety of imported maize.  相似文献   

13.
The aim of this study was a monitoring of the occurrence ofAlternaria andFusarium mycotoxins in winter wheat from domestic crop in the year 2003. Altenuene was determined in 56 (100%) samples of winter wheat, range 14.5–41 μg/kg, mean 25 μg/kg. Alternariol was determined in 16 (28.6%) samples of winter wheat, range 6.3–22.1 μg/kg, mean 5.7 μ/kg. DON was determined in 42 (100%) samples of winter wheat, range 250–3500 μg/kg, mean 330 μg/kg. T2-toxin was determined in 42 (100%) samples of winter wheat, range 25–337 μg/kg, mean 99 μg/kg. ZEA was not determined in samples of winter wheat. Presented at the 26th Mykotoxin-Workshop in Herrsching, Germary, May 17–19, 2004 Financial support. Supported (one part of experiments, the determination of Fusarium mycotoxins) by the Ministry of Agricu ture of the Czech Rebublic (Propect No QF3121)  相似文献   

14.
Simultaneous extraction and separation of liquiritin, glycyrrhizic acid, and glabridin from licorice were developed by liquidliquid extraction with liquid chromatography separation. By utilizing different extraction solvents, procedures, and times, the optimum extraction conditions were established. The extracts of licorice were separated and determined using a C18 column with a mobile phase consisting of acetonitrile-water (containing 1.0% acetic acid) with a gradient elution of 0∼10 min from 20:80 to 60:40 (v/v). Preparative columns with different packing sizes were investigated to isolate the three compounds from the extracts of licorice. The 12 μm chromatographic column showed better separation for the three compounds from licorice. 0.29 mg/g for liquiritin, 1.43 mg/g for glycyrrhizic acid, and 0.07 mg/g for glabridin were obtained and the recoveries were 80.8, 89.7, and 72.5%, respectively.  相似文献   

15.
Biomass and eicosapentaenoic acid (EPA) productivities were investigated in a flat panel airlift loop reactor ideally mixed by static mixers. Growth with ammonium, urea and nitrate as nitrogen source were performed at different aeration rates. Cultures grew on ammonium but the decay of pH strongly inhibited biomass increase. On urea biomass productivity reached 2.35 g L–1d–1at an aeration rate of 0.66 vvm (24 h light per day, 1000 mol photon m–2s–1). Aeration rates between 0.33 vvm and 0.66 vvm and maximal productivities on urea were linearly dependent. Productivity on nitrate never exceeded 1.37 g L–1d–1. In the range of maximum productivity photosynthesis efficiency of 10.6% was reached at low irradiance (250 mol photon m–2s–1). Photosynthesis efficiency decreased to 4.8% at 1000 mol photon m–2s–1. At these high irradiances the flat panel airlift reactor showed a 35% higher volume productivity than the bubble column. At continuous culture conditions the influence of CO2concentration in the supply air was tested. Highest productivities were reached at 1.25% (v/v) CO2where the continuous culture yielded 1.04 g L–1d–1(16 h light per day, 1000 mol photon m–2s–1). The average EPA content amounted to 5.0% of cell dry weight, that resulted in EPA productivities of 52 mg L–1d–1(continuous culture, 16 h light per day) or 118 mg L–1d–1(batch culture, 24 h light per day).  相似文献   

16.
The Alternaria mycotoxin tenuazonic acid (TA) was quantified in fruit juices (n = 50), cereals (n = 12) and spices (n = 38) using a recently developed stable isotope dilution assay (SIDA). [13 C6,15 N]-TA was used as the internal standard. Method validation revealed low limits of detection (LODs) of 0.15 μg/kg (fruit juices), 1.0 μg/kg (cereals) and 17 μg/kg (spices). The respective limits of quantitation were about three times higher. Recovery was about 100% for all matrices. The precision (relative standard deviation of replicate analyses of naturally contaminated samples) was 4.2% (grape juice; 1.7 μg/kg), 3.5% (whole wheat flour; 36 μg/kg) and 0.9% (curry powder; 215 μg/kg). The median content of TA in the analyzed samples was 1.8 μg/kg (fruit juices), 16 μg/kg (cereals) and 500 μg/kg (spices). Positive samples amounted to 86% (fruit juices), 92% (cereals) and 87% (spices).  相似文献   

17.
Summary Shoot multiplication of Zingiber officinale cv. V3S18 was achieved by meristem culture on a Murashige and Skoog (MS) basal medium supplemented with 26.6 μM 6-benzylaminopurine (BA), 8.57 μM indole-3-acetic acid (IAA), and 1111.1 μM adenine sulfate and 3% (w/v) sucrose. In vitro rhizome formation from in vitro-raised shoots was achieved on MS medium supplemented with 4.44 μM BA, 5.71 μM IAA, and 3–8% (w/v) sucrose after 8 wk of culture. Cultural variations such as photoperiod, carbohydrate, nutrient composition, and growth regulators were tested for the maximum yield of rhizomes. Among the different photoperiods used, a 24-h photoperiod helped in the formation of more rhizomes as compared with other photoperiods. Of the different carbohydrates used, sucrose helped to achieve rhizome formation as compared to other carbohydrates. The microrhizomes sprouted in a soil mixture within 2 wk of planting. The sprouted plantlets survived under field conditions with normal growth.  相似文献   

18.
The possibility of a role for phosphate metabolism in the photosynthetic regulation that occurs during frost hardening was investigated in winter rye (Secale cereale L. cv. Musketeer). Leaves of frost-hardened and non-hardened winter rye were studied during photosynthetic induction, and at steady state after being allowed to take up 20 mM orthophosphate through the transpiration stream for 3 h. At the growth irradiance (350 mol·m-2·s-1) frost-hardening increased the stationary rate of CO2-dependent O2 evolution by 57% and 25% when measured at 5 and 20° C, respectively. Frosthardening also reduced the lag phase to stationary photosynthesis by 40% at 5° C and decreased the susceptibility of leaves to oscillations during induction and after interruption of the actinic beam during steady-state photosynthesis. These responses are all indicative of increased phosphate availability in frost-hardened leaves. As reported previously by Öquist and Huner (1993, Planta 189, 150–156), frost-hardening also decreased the reduction state of QA, the primary, stable quinone acceptor of PSII, and decreased the sensitivity of winter rye to photoinhibition of photosynthesis. Non-hardened rye leaves fed orthophosphate also showed an increased photosynthetic capacity (25% at 20° C and light saturation), lower reduction state of QA, a reduced sensitivity to photoinhibition and lower susceptibility to oscillations resulting from a brief interruption of the actinic light. Thus, the data indicate that phosphate metabolism plays a key role in photosynthetic acclimation of winter rye to low temperatures.Abbreviations Fo and Fo minimal fluorescence when all PSII reaction centres are open in dark-and light-acclimated leaves, respectively - Fm and Fm maximal fluorescence when all PSII reaction centres are closed in dark-and light-acclimated leaves, respectively - Fv variable fluoresence (Fm -Fo) in dark-acclimated leaves - Fv variable fluorescence (Fm-Fo) in light-acclimated leaves - PCR photosynthetic carbon reduction - PPFD photosynthetic photon flux density - QA the primary, stable quinone acceptor of PSII - qP photochemical quenching of fluorescence - qN non-photochemical quenching of fluorescence This work was supported by the Swedish Natural Sciences Research Council. The authors are indebted to Dr. N. Huner, Department of Plant Sciences, UWO, London, Canada, for helpful discussions during the initiation of this work and for the gift of rye seeds.  相似文献   

19.
AFM1 was determined in 72 (72%) samples of human urine, range 19-6064 pg/g creatinine, mean 367 pg/g creatinine, median 158 pg/g creatinine and 90% percentile 755 pg/g creatinine in 1997. AFM1 was determined in 46 (43.8%) samples of human urine, range 21-19219 pg/g creatinine, mean 414 pg/g creatinine, median 96 pg/g creatinine and 90% percentile 415 pg/g creatinine in 1998. OTA was determined in 2077 (94.2%) samples of human serum, range 0.1–13.7 μg/L, mean 0.28 μg/L, median 0.2 μg/L and 90% percentile 0.5 μg/L in 1994–2002. OTA was determined in 12 (40%) samples of human kidneys, range 0.1–0.2 μg/kg, mean 0.07 μg/kg, and median 0.05 μg/kg in 2001. Presented at the 26th Mykotoxin-Workshop in Herrsching, Germany, May 17–19, 2004.  相似文献   

20.
An in vitro propagation protocol has been developed from mature trees of Pittosporum napaulensis. The best bud proliferation (83.1%), shoot number (21 axillary shoots/ explant) and shoot length (5.5 cm) was achieved in Murashige and Skoog (MS) medium supplemented with 5.0 μM N−6 benzyladenine and 0.1 μM α- naphthalene acetic acid. Of the three cytokinins tested (N−6 benzyladenine, kinetin and thidiazuron), N−6 benzyladenine proved to be the best for shoot induction. Shoot regeneration potential varied among genotypes. Regenerated shoots rooted after 48 hours treatment on half-strength MS liquid medium supplemented with 20 μM indole-3-butyric acid. Rooted shoots transferred to 120 g (w/v) soilrite + sand + soil (1:1:1) mixture showed 70% survival. Twenty-one plantlets are growing well in green house conditions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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