Contamination Of Grains Research Articles

CEREALS ASSESSMENT TOWARDS CONTAMINATION OF PHYTOPATHOGENIC FUNGI IN FOREST-STEPPE AREA OF UKRAINE

The usage of high-quality seed, not affected by pathogens and fungi promote the high and stable yields. The condition of seeds determines their germination, seedling damage and adult plants, which ultimately affects the yield and on their quality. The significant risk of seed infection was registered in years with high humidity in the pre-harvest and harvest period. Therefore, along with the traditional seed control it is necessary to conduct phytopahtology expertise, allowing to identify the species composition of the microflora of seeds and the degree of infection with different pathogens. Smut disease - a solid and loose smut of wheat, hard and loose smut of barley - cause crop losses are clear - in the form of the destruction of the ear, and hidden - in the form of a reduction in seed germination, reduce winter hardiness, plant growth inhibition. Pathogens root rot causing blight, Fusarium and Helminthosporium that insignificantly demand on environmental conditions and extremely plastic. They have large set of enzymes that can exist on a variety of substrates, and therefore are widely distributed in nature and cause considerable damage to crops. Especially significant losses occur if the humidity during the ripening grain observed for several seasons, which leads to accumulation of the infection naturally. The aim of research was to assess the contamination of grain of spring wheat and barley phytopathogenic fungi in one of the main grain regions of Ukraine - the southern forest. The research conducted during the summer 2014 and compared with the results of previous years. Samples were taken from different plots. Seed contamination of samples by various phytopathogenic fungi was determined by the number of infected kernels per 100 seed sample. Frequency of registered species was recorded. For every studied sample we set the percentage of species. Analysis of the grain on the fungal infection and avdelenie in pure culture was performed according to the procedures used a method of washing and centrifugation, seeds, embryos analysis method, biological method based on the stimulation of development and growth of pathogens in the infected seeds during seed germination in nutrient media. We analyzed 200 samples of wheat and barley grain with 8 games on the definition of the infestation and root rot spores solid and smut. In all the samples studied was dominated latent form of infection grains (outwardly healthy, germinating, well executed seeds had normal luster, patina fungus was absent); but sometimes observed apparent lesion (plaque formation, a different degree of deformation of grains). When the microscope isolated fungi was established dominance of species such as fungi of the genera Alternaria, Helmintosporium, Fusarium, smut fungi. The research of cereal seeds showed that all the tested party for the harvest in 2014 were infected with different pathogens in different degrees. On the basis of literature data and our own observations, comparing infection rates average cereal seeds complex fungal diseases, it may be noted that in 2014 the percentage of infestation was higher than in previous years, there is a trend of growth in incidence. The results showed that the overall percentage of infected root rots seeds of spring wheat in 2014 was 55.5 %, the infestation of spring barley was 64.7 %. Compared to previous years the trend increase in the prevalence of fungal diseases on cereals: wheat infestation grew by 12.8 %, barley - 2.13 %. Smut infected - 11.2 % wheat, barley - 37.4 %. Infection bunt was 4.6 %, including 3.3 % of wheat; Barley 17.6 %. The growth and development of root rot during the growing season depended on the presence of soil infection. Infection of grain crops by smut diseases depend on the quality of seed sown. Reducing the prevalence of smut disease is possible at early winter and late spring sowing to prevent the spore germination at low temperature. Keywords: seeds, disease, infection, agents of fungal diseases, spores.

Peanut Resistance Gene Expression in Response to Aspergillus flavus Infection During Seed Germination

AbstractAspergillus flavus produces potent mutagenic and carcinogenic polyketide‐derived secondary metabolites known as aflatoxins. Development of host plant resistance in peanut and other crops is the most environmentally friendly and cost‐effective method to eliminate the serious problem of aflatoxin contamination in grains. To confirm that putative peanut genes identified in a previous microarray study were involved in peanut resistance to A. flavus infection, 14 genes were selected for further investigation through real‐time PCR. The results revealed diverse patterns of gene expression during seed germination after A. flavus inoculation. Based on the expression levels and the relative‐expression patterns over a 7‐day period, the 14 host genes could be classified into six different groups belonging to three main biochemical and genetic defence processes of lipid metabolism, oxidative signalling and cell‐wall synthesis during counter‐attack. A network of gene expression patterns was activated in sequential order in response to A. flavus invasion in both resistant and susceptible peanut lines during seed germination. Understanding gene expression patterns in peanut will be useful to breeders and other scientists interested in incorporating genetic resources of resistance against A. flavus into peanut germplasm and/or commercial cultivars via conventional and/or molecular methods.

Bioguided isolation, characterization, and biotransformation by Fusarium verticillioides of maize kernel compounds that inhibit fumonisin production.

Fusarium verticillioides infects maize ears, causing ear rot disease and contamination of grain with fumonisin mycotoxins. This contamination can be reduced by the presence of bioactive compounds in kernels that are able to inhibit fumonisin biosynthesis. To identify such compounds, we used kernels from a maize genotype with moderate susceptibility to F. verticillioides, harvested at the milk-dough stage (i.e., when fumonisin production initiates in planta), and applied a bioguided fractionation approach. Chlorogenic acid was the most abundant compound in the purified active fraction and its contribution to fumonisin inhibitory activity was up to 70%. Moreover, using a set of maize genotypes with different levels of susceptibility, chlorogenic acid was shown to be significantly higher in immature kernels of the moderately susceptible group. Altogether, our data indicate that chlorogenic acid may considerably contribute to either maize resistance to Fusarium ear rot, fumonisin accumulation, or both. We further investigated the mechanisms involved in the inhibition of fumonisin production by chlorogenic acid and one of its hydrolyzed products, caffeic acid, by following their metabolic fate in supplemented F. verticillioides broths. Our data indicate that F. verticillioides was able to biotransform these phenolic compounds and that the resulting products can contribute to their inhibitory activity.

Inhibitory effect of essential oils on Aspergillus ochraceus growth and ochratoxin A production.

Ochratoxin A (OTA) is a mycotoxin which is a common contaminant in grains during storage. Aspergillus ochraceus is the most common producer of OTA. Essential oils play a crucial role as a biocontrol in the reduction of fungal contamination. Essential oils namely natural cinnamaldehyde, cinnamon oil, synthetic cinnamaldehyde, Litsea citrate oil, citral, eugenol, peppermint, eucalyptus, anise and camphor oils, were tested for their efficacy against A. ochraceus growth and OTA production by fumigation and contact assays. Natural cinnamaldehyde proved to be the most effective against A. ochraceus when compared to other oils. Complete fungal growth inhibition was obtained at 150–250 µL/L with fumigation and 250–500 µL/L with contact assays for cinnamon oil, natural and synthetic cinnamaldehyde, L. citrate oil and citral. Essential oils had an impact on the ergosterol biosynthesis and OTA production. Complete inhibition of ergosterol biosynthesis was observed at ≥100 µg/mL of natural cinnamaldehyde and at 200 µg/mL of citral, but total inhibition was not observed at 200 µg/mL of eugenol. But, citral and eugenol could inhibit the OTA production at ≥75 µg/mL and ≥150 µg/mL respectively, while natural cinnamaldehyde couldn’t fully inhibit OTA production at ≤200 µg/mL. The inhibition of OTA by natural cinnamaldehyde is mainly due to the reduction in fungal biomass. However, citral and eugenol could significant inhibit the OTA biosynthetic pathway. Also, we observed that cinnamaldehyde was converted to cinnamic alcohol by A. ochraceus, suggesting that the antimicrobial activity of cinnamaldehyde was mainly attributed to its carbonyl aldehyde group. The study concludes that natural cinnamaldehyde, citral and eugenol could be potential biocontrol agents against OTA contamination in storage grains.

Efektivitas Bioremedian dan Konsorsia Mikroba Penyubur terhadap Produksi dan Kandungan Timbal Gabah di Karanganyar

<p>Food need in Indonesia always increases while its production tends to decrease. One of factors causing it is contaminants in agricultural environment including lead (Pb). This research aimed to study the effectiveness of bioremediation and microbial consortia fertilizers in increasing rice production and decreasing lead contamination in grain. The research started in August 2013 to February 2014 in village Waru and Kebak, Kebakkramat, Karanganyar, using Nested Factorial Treatment Design and Complete Randomized Block Design with two factors those are bioremediation variety and combination microbial fertilizers with chemical fertilizers. Statistical analysis used F-test, Kruskal Wallis,Tukey 5%, Mood Median, correlation test and regression. Research result showed best production was achieved at V2P1 (Pepe + Azolla 0,183 ton ha<sup>-1</sup>, microbial fertilizer 0,56 ton ha<sup>-1</sup> and chemical fertilizers 50% of farmer standard), that is highest result is achieved at total number of tillers (35,64), number of productive tillers (25,72), Dry Grain (11 ton ha<sup>-1</sup>) and Dry Milled Grain (8,7 ton ha<sup>-1</sup>). Azolla microphylla, microbial fertilizer and chemical fertilizers 50% of farmer standard treat was effective to reduce heavy metal residues because lead residues were not found on the grain (0 ppm).</p>

A Rapid Determination of Ergosterol in Grains Using Gas Chromatography–Mass Spectrometry Method Without Derivatization

Asimple,rapidandsensitiveGC-MSmethodusing on-column injection was developed and validated to deter- mine ergosterol (ERG) levels in maize and wheat. In this method, ERG was extracted from grains with methanol and partitioned into hexane. The hexane layer was then directly injected onto the on-column GC-MS injection system without column-clean up or derivatization. Optimization of different GC-MS parameters was evaluated to obtain maximum sensi- tivity. Matrix-matched calibration curves were constructed to compensate for matrix effects in both matrices. Good recov- eries in maize (98-110 %) and wheat (96-110 %) samples were obtained at three spiking levels (1, 3, and 8 mg/kg), with relative standard deviations less than 8 % in maize and 7 % in wheat. The limits of detection and quantification of ERG were less than 40 μg/kg and 200 μg/kg of grain sample, respectively. The method was successfully applied to 37 marketed grains, with ERG concentrations ranging from 1.0 to 14.4 mg/kg. Moreover, GC-MS analyses data were compared with an HPLC method, and no significant dif- ference was observed. This new GC-MS method is quick and reliable for routine analysis of ERG to monitor fungal invasion and possible mycotoxin contamination in grains.

Effect of fumonisin-containing diet on the myenteric plexus of the jejunum in rats.

Fumonisins are mycotoxins that naturally occur as contaminants in grains that are destined for animal and human consumption. These mycotoxins cause hepatotoxic, nephrotoxic, carcinogenic, teratogenic, immunotoxic, and neurotoxic effects in different intensities based on dose, time of exposure, and animal species. In the present study, male Wistar rats were fed between postnatal days 21 and 63 with diets that contained fumonisins B1+B2 at concentrations of 1 and 3mg/kg. The objective of the present study was to evaluate the effects of fumonisins on food intake, growth, weight gain, serum activity of the alanine aminotransferase and aspartate aminotransferase enzymes, and quantitative and morphometric parameters of myenteric neurons in the jejunum that are immunoreactive to HuC/D protein and neuronal nitric oxide synthase enzyme (nNOS). Diets that contained fumonisins did not significantly alter food intake or body and blood parameters. We did not observe significant differences in the neuronal density and proportion of nitrergic neurons but found a significant reduction of cell body areas in both neuronal populations. This study is the first to report the effects of fumonisins in the enteric nervous system. The possible mechanisms by which fumonisins impair neuronal development and the use of the enteric nervous system as a tool for the study of the neurotoxic effects of fumonisins are discussed. In conclusion, fumonisin-containing food negatively affected the growth of myenteric neurons.

Zearalenone exposure affects mouse oocyte meiotic maturation and granulosa cell proliferation.

Zearalenone (ZEN) is a metabolite of Fusarium and is a common contaminant of grains and foodstuffs. ZEN acts as a xenoestrogen and is considered to be cytotoxic, tissue toxic, and genotoxic, which causes abortions and stillbirths in humans and animals. Since estrogens affect oocyte maturation during meiosis, in this study we investigated the effects of ZEN on mouse oocyte meiotic maturation and granulosa cell proliferation. Our results showed that ZEN-treated oocyte maturation rates were decreased, which might be due to the disrupted cytoskeletons: (1) ZEN treatment resulted in significantly more oocytes with abnormal spindle morphologies; (2) actin filament expression and distribution were also disrupted after ZEN treatment, which was confirmed by the aberrant distribution of actin regulatory proteins. In addition, cortical granule-free domains (CGFDs) were disrupted after ZEN treatment, which indicated that ZEN may affect mouse oocyte fertilization capability. ZEN reduced mouse granulosa cell proliferation in a dose-dependent manner as determined by MTT assay and TUNEL apoptosis analysis, which may be another cause for the decreased oocyte maturation. Thus, our results demonstrated that exposure to zearalenone affected oocyte meiotic maturation and granulosa cell proliferation in mouse.

Distinguishing between toxic and non-toxic pyrrolizidine alkaloids and quantification by liquid chromatography–mass spectrometry

Pyrrolizidine alkaloids (PAs) are important plant toxins causing poisoning in livestock, leading to significant financial and production losses each year. It may also enter the human food chain as contaminants of grains, via animal products such as milk, eggs and honey or herbal remedies. Not all PAs are toxic and it is important to be able to distinguish between toxic and non-toxic PAs. We developed a sensitive and selective analytical method to determine toxic 1,2-unsaturated PAs concentrations in plant extracts by liquid chromatography–mass spectrometry (LC–MS) with electrospray ionization and precursor ion experiments. Multi-reaction-mode experiments were used to quantify the concentrations of the different unsaturated PAs and results were expressed as μg/g retrorsine equivalents. The results obtained on Crotalaria sphaerocarpa contaminating maize crops have important implications.

A Simple Method for the Assessment of Fusarium Head Blight Resistance in Korean Wheat Seedlings Inoculated with Fusarium graminearum.

Fusarium head blight (FHB; scab) caused mainly by Fusarium graminearum is a devastating disease of wheat and barley around the world. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON) which are a major health concern for humans and animals. The objective of this research was to develop an easy seed or seedling inoculation assay, and to compare these assays with whole plant resistance of twenty-nine Korean winter wheat cultivars to FHB. The clip-dipping assay consists of cutting off the coleoptiles apex, dipping the coleoptiles apex in conidial suspension, covering in plastic bag for 3 days, and measuring the lengths of lesions 7 days after inoculation. There were significant cultivar differences after inoculation with F. graminearum in seedling relative to the controls. Correlation coefficients between the lesion lengths of clip-dipping inoculation and FHB Type II resistance from adult plants were significant (r=0.45; P<0.05). Results from two other seedling inoculation methods, spraying and pin-point inoculation, were not correlated with adult FHB resistance. Single linear correlation was not significant between seed germination assays (soaking and soak-dry) and FHB resistance (Type I and Type II), respectively. These results showed that clip-dipping inoculation method using F. graminearum may offer a real possibility of simple, rapid, and reliable for the early screening of FHB resistance in wheat.

Composição química e desoxinivalenol em trigo da região Centro- Sul do Paraná: adubação nitrogenada em cobertura associada com Azospirillum brasilense

The impact of agricultural management practices on the quality of grain was evaluated in wheat ( Triticum aestivum L. BRS Tangara) from the South Central region of Parana State (Ponta Grossa) in the crop years of 2010 and 2011. The field trial was carried out in succession with soybean (2010) and corn (2011). The treatments included inoculation of seeds with Azospirillum brasilense and increasing levels of nitrogen application in top dressing (0, 30, 60, 90 and 120 kg ha-1). The experimental design was in randomized block, factorial 2 x 5 (inoculation x N levels), with four replications. The parameters evaluated were water activity, moisture, protein, and grain contamination by deoxynivalenol (DON). The data were subjected to analysis of variance, comparison of means by Tukey’s test (p<0.05) and regression for nitrogen levels. The inoculation of seeds with A. brasilense increased the protein content in grain in 2010 (+1.6%; 16.9 g 100g-1) and 2011 (+1.7%, 15.7 g 100g-1), independently of the nitrogen level (p<0.01). Levels of nitrogen in 2010 presented a positive linear response with protein content, increasing by 14.2% using non-inoculated seeds (p<0.01, R2=0.955) and 14.4% for those inoculated with A. brasilense (p<0.01, R2=0.906). However, in 2011 a quadratic response was observed between nitrogen levels and protein content (p<0.01, R2=0.99), with stabilization or reduction in protein content using high levels of nitrogen (?120 kg ha-1). The contamination by DON was greater using high levels of nitrogen (3574 ?g kg-1, 120 kg ha-1; non-inoculated seeds) in 2011, with a quadratic response between nitrogen levels and contamination of grains (p<0.05, R2=0.772). Furthermore, 37.5% of the samples presented contamination by DON higher than the maximum tolerated limit established by Brazilian legislation (2000 ?g kg-1; whole-wheat grain). The data demonstrates that proper management of nitrogen enhances intrinsic effects arising from plant breeding.

Population dynamics of the Fusarium head blight biocontrol agent Cryptococcus flavescens OH 182.9 on wheat anthers and heads

Cryptococcus flavescens OH 182.9 (NRRL Y-30216) reduces Fusarium head blight (FHB) incited by Fusarium graminearum and deoxynivalenol (DON) contamination of grain. Yet little is known about the population dynamics of OH 182.9 on wheat heads and anthers. Biomass of OH 182.9 was produced in liquid culture and applied to greenhouse and field grown wheat prior to and during early anthesis. In greenhouse studies, populations of OH 182.9 were similar on anthers for heads inoculated before (Feekes 10.5) or early in flowering (Feekes 10.5.1) but were 1–3 log units lower in Feekes 10.5 inoculated wheat after 8–10days. In greenhouse and field studies, OH 182.9 colonized anthers inside florets prior to anthesis. In the field, populations of OH 182.9 on anthers increased or, less frequently, remained stable through 12days, regardless of application time and peaked at 1–2 log units higher than in the greenhouse. Strain OH 182.9 reduced FHB severity (P<0.05, FPLSD) but not other disease parameters in the same field study. Application of OH 182.9 at split boot (Feekes 10.1) or Feekes 10.5.1 resulted in higher populations on spikelets treated at flowering on a CFU/g fresh weight tissue basis and as a percentage of the total recoverable microbial population in one of two field studies. Scanning electron microscopy revealed cells of OH 182.9 in microcolonies, groups of several cells and as individual cells, most frequently on the abaxial surfaces of glume and lemma tissues and near the apex of palea tissues. The survival of yeast OH 182.9 on anthers and wheat heads for 12days and more suggests the strain has the potential to reduce late kernel infections by F. graminearum that can increase DON.

Assessment and Introduction of Quantitative Resistance to Fusarium Head Blight in Elite Spring Barley

Breeding for resistance is a key task to control Fusarium head blight (FHB), a devastating disease of small cereals leading to economic losses and grain contamination with mycotoxins harmful for humans and animals. In the present work, FHB resistance of the six-rowed spring barley 'Chevron' to FHB in Germany was compared with those of adapted German spring barley cultivars. Both under natural infection conditions and after spray inoculation with conidia of Fusarium culmorum, F. sporotrichioides, and F. avenaceum under field conditions, Chevron showed a high level of quantitative resistance to the infection and contamination of grain with diverse mycotoxins. This indicates that Chevron is not only a little susceptible to deoxynivalenol-producing Fusarium spp. but also to Fusarium spp. producing type A trichothecenes and enniatins. Monitoring the initial infection course of F. culmorum on barley lemma tissue by confocal laser-scanning microscopy provided evidence that FHB resistance of Chevron is partially mediated by a preformed penetration resistance, because direct penetration of floral tissue by F. culmorum was observed rarely on Chevron but was common on susceptible genotypes. Alternatively, F. culmorum penetrated Chevron lemma tissue via stomata, which was unusual for susceptible genotypes. We generated double-haploid barley populations segregating for the major FHB resistance quantitative trait loci (QTL) Qrgz-2H-8 of Chevron. Subsequently, we characterized these populations by spray inoculation with conidia of F. culmorum and F. sporotrichioides. This suggested that Qrgz-2H-8 was functional in the genetic background of European elite barley cultivars. However, the degree of achieved resistance was very low when compared with quantitative resistance of the QTL donor Chevron, and the introgression of Qrgz-2H-8 was not sufficient to mediate the cellular resistance phenotype of Chevron in the European backgrounds.

Brassinosteroid Enhances Resistance to Fusarium Diseases of Barley

Fusarium pathogens are among the most damaging pathogens of cereals. These pathogens have the ability to attack the roots, seedlings, and flowering heads of barley and wheat plants with disease, resulting in yield loss and head blight disease and also resulting in the contamination of grain with mycotoxins harmful to human and animal health. There is increasing evidence that brassinosteroid (BR) hormones play an important role in plant defense against both biotic and abiotic stress agents and this study set out to determine if and how BR might affect Fusarium diseases of barley. Application of the epibrassinolide (epiBL) to heads of 'Lux' barley reduced the severity of Fusarium head blight (FHB) caused by Fusarium culmorum by 86% and reduced the FHB-associated loss in grain weight by 33%. Growth of plants in soil amended with epiBL resulted in a 28 and 35% reduction in Fusarium seedling blight (FSB) symptoms on the Lux and 'Akashinriki' barley, respectively. Microarray analysis was used to determine whether growth in epiBL-amended soil changed the transcriptional profile in stem base tissue during the early stages of FSB development. At 24 and 48 h post F. culmorum inoculation, there were 146 epiBL-responsive transcripts, the majority being from the 48-h time point (n = 118). Real-time reverse-transcription polymerase chain reaction analysis validated the results for eight transcripts, including five defense genes. The results of gene expression studies show that chromatin remodeling, hormonal signaling, photosynthesis, and pathogenesis-related genes are activated in plants as a result of growth in epiBL.

Conjugation of deoxynivalenol by Alternaria alternata (54028 NRRL), Rhizopus microsporus var. rhizopodiformis (54029 NRRL) and Aspergillus oryzae (5509 NRRL)

Deoxynivalenol (DON, vomitoxin) is a trichothecene mycotoxin which can be considered to be an indicator of Fusarium mycotoxin contamination in grain, feed and food. Recent studies have described the presence of glucose conjugated DON, which is a product of plant metabolism, but there is a lack of information available on DON conjugation by fungi. The aim of the current study was, therefore, to investigate the ability of fungi to metabolize DON into hydrolysable conjugated DON. Alternaria alternata (54028 NRRL) and Rhizopus microsporus var. rhizopodiformis (54029 NRRL) were found to be capable of metabolizing DON into hydrolysable conjugated DON. This ranged from 13-23% conjugation of DON in potato dextrose agar media and from 11-36% in corn-based media. There was, however, considerable variation between fungal strains in the ability to conjugate DON as only a slight increase in hydrolysable conjugated DON (1-6%) was observed when incubating with A. oryzae (5509 NRRL). A. oryzae (5509 NRRL) was also shown to degrade DON (up to 92%) over 21days of incubation on corn-based media. The current study shows that conjugation of DON can be achieved through fungal metabolism in addition to being a product of plant metabolism.

Field evidence of roof rat (Rattus rattus) faecal contamination of barley grain stored in silos in the Czech Republic

This study represents the first European report of a risk assessment for the contamination of grain by roof rats' (Rattus rattus L.) faeces in silo structures that have traditionally been considered to be rodent-contaminant proof. In this work, we estimated the rate and magnitude of grain and grain transport silo technology contamination by faeces of R. rattus and identified the routes of entry of rodent faeces into grain stored in silos. We also compared the sizes of rat faeces and stored barley grains to determine whether they could easily be separated using sieves. We found that roof rats were able to heavily contaminate grain surfaces and conveyor belts with faecal deposits during a 3-week observation period. The average contamination rate was 6.90 ± 0.92 faeces/m 2 (range 0-26 faeces/m 2 ) for grain surfaces and 34.80 ± 8.03 faeces/m 2 (range 8-87 faeces/m 2 ) for conveyor belts. The size measurements (length, width and surface area) of rat faeces and barley grains showed their high similarity; these results therefore indicate that the physical separation of the two materials using sieves will be problematic.

Transcriptional regulation of enniatins production by Fusarium avenaceum

The aim of this study was to analyse the transcriptional regulation of enniatins (ENs) production in Fusarium avenaceum. We develop a new method to quantify ENs in FDM agar medium. We performed an LC/MS/MS analysis to evaluate enniatin A, A1, B, B1 and B4 production by seven F. avenaceum strains and, in a time-course experiment, by ITEM 3404 to analyse the transcriptional regulation of the esyn1 gene. The expression profile, achieved by Real time reverse transcriptase assay, showed an activation of gene transcription at the seventh day of incubation, corresponding to the higher increase of total ENs production. Enniatin B was the most abundant ENs analogues, representing the 90% of total ENs. The relative percentage of ENs remained unaltered during the experiment. We reported a transcriptional regulation of esyn1 responsible for the modulation of ENs biosynthesis. Enniatins are cyclic depsipeptides metabolites with a wide range of biological activities. They are also widespread contaminants in grains and cereals due to infection by enniatin-producing Fusarium species. This is the first article describing the transcriptional regulation of esyn1 gene that modulates ENs production in Fusarium avenaceum and provides new knowledge about the molecular mechanism underlying the biosynthesis of these important fungal metabolites in this toxigenic fungal species.

Decay of Salmonella enterica ,Escherichia coli and bacteriophage MS2 on the phyllosphere and stored grains of wheat (Triticum aestivum )

Cereal crops grown in the biosolids-amended soil can potentially become contaminated with pathogenic micro-organisms during growth and at the time of harvesting. There is small but unquantified potential risk of transfer of enteric pathogens to humans and animals from contaminated plants and grains. This study examined decay of Escherichia coli, Salmonella enterica serovar Typhimurium and bacteriophage MS2 on the wheat phyllosphere and on stored grains. This was done to assess the health implications of cereal crops contaminated from land application of biosolids. E. coli, S. enterica and MS2 were inoculated onto the leaves, spikelets and grains of wheat. The change in the numbers of inoculated micro-organisms was determined over time to calculate the respective 90% reduction time (T90 ) in each of these environments. A rapid inactivation (T90 <1-3 days) of E. coli and S. enterica and MS2 from the plant phyllosphere was observed, particularly from the spikelets. The decay rates were influenced by micro-organism type and location on the plant phyllosphere. Decay times on the stored grains were longer (T90 9-71 days), with some observed influence of grain variety on pathogen decay times. Results of this study suggest that there is very limited potential of enteric pathogens survival on wheat phyllosphere and grains. Therefore, the risk of transfer of enteric pathogens from biosolids-amended soil to consumers of grain products is considered to be low. This study has important implications for the grains industry, as the results suggest that chances of preharvest contamination of grains with enteric pathogens from biosolids-amended soil are low.

Free and total levels of estrogenic mycotoxins in girls in California and New Jersey

Background: There is a growing interest in the role of zearalenone (ZEA) and zeranol on puberty and breast cancer because of ample experimental evidence shows they act as endocrine disruptors. ZEA is a mycotoxin produced by fungal contamination of grains and other food products. Its metabolite, zeranol is commonly used in cattle to increase meat production in the US, although banned from other countries. Little is known about the metabolism and health effects of these compounds in humans. In pigs, ZEA is rapidly absorbed after ingestion and conjugated with glucuronic acid before it is excreted in urine. Therefore, most of the ZEA metabolites should be in conjugated form in urine, but the conjugated fraction in girls is unknown. Aims: To measure ZEA mycotoxins in two areas of the US to determine detectability and conjugated fraction in girls. Methods: We measured urinary free and total (free + conjugated) ZEA mycotoxins in 20 girls in the Jersey Girl Study (age 9-10 y), based in NJ, and 20 girls from the CYGNET Study (age 7-8 y), based in the San Francisco Bay Area, CA. We corrected values for specific gravity to adjust for urinary concentration. Results: Conjugated fractions were above 90% for ZEA and zeranol. Total ZEA was detected in all samples in both populations, with median values of 15,917 pg/ml in CA and 5,325 pg/ml in NJ. Free ZEA was detected in 79% of the CA samples (median: 439 pg/ml) and 40% of the NJ samples (median: 0, mean: 38 pg/ml). Total zeranol was present in 79% of the CA samples (median: 2,392 pg/ml) and 50% of the NJ samples (median: 42 pg/ml), while free zeranol was detected only in CA and levels were low. Conclusions. Total ZEA and related metabolites were present in all the samples in both populations, mostly in conjugated form, with levels for all compounds considerably higher in CA than in NJ. Further studies are critically needed to evaluate the health effects of these widely-detected estrogenic mycotoxins in peripubertal girls.

Poisoning by British Plants

The properties of poisonous plants have been recognised for thousands of years. To-day we see the active constituents of some such plants, accurately determined and concentrated in tablets and mixtures, used in the practice of therapeutics.Cases of poisoning by plants though now uncommon, do still occur occasionally. Various factors are responsible for the drop in incidence over the last century. The general standard of living has been raised and people no longer require to supplement their diet with roots and fruits on pain of starvation, when mistakes are liable to occur. Better education combined with suspicions as to the wholesomeness of various fruits provides a barrier against reckless indulgence. Farming is carried out intensively and crops arc cleaner than before, thus reducing possible contamination of grain. The potential murderer or suicide now has the vast range of dangerous drugs to choose from provided he can obtain them. Many of the plants themselves have now a limited distribution. The using of any available land for grazing or ploughing and the drainage of marshes, burning of scrub and felling of timber has reduced the available habitats.