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Sample records for aflatoxin af biosynthesis

  1. Aflatoxin biosynthesis: current frontiers.

    PubMed

    Roze, Ludmila V; Hong, Sung-Yong; Linz, John E

    2013-01-01

    Aflatoxins are among the principal mycotoxins that contaminate economically important food and feed crops. Aflatoxin B1 is the most potent naturally occurring carcinogen known and is also an immunosuppressant. Occurrence of aflatoxins in crops has vast economic and human health impacts worldwide. Thus, the study of aflatoxin biosynthesis has become a focal point in attempts to reduce human exposure to aflatoxins. This review highlights recent advances in the field of aflatoxin biosynthesis and explores the functional connection between aflatoxin biosynthesis, endomembrane trafficking, and response to oxidative stress. Dissection of the regulatory mechanisms involves a complete comprehension of the aflatoxin biosynthetic process and the dynamic network of transcription factors that orchestrates coordinated expression of the target genes. Despite advancements in the field, development of a safe and effective multifaceted approach to solve the aflatoxin food contamination problem is still required.

  2. How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus

    PubMed Central

    Reverberi, Massimo; Punelli, Marta; Smith, Carrie A.; Zjalic, Slaven; Scarpari, Marzia; Scala, Valeria; Cardinali, Giorgia; Aspite, Nicaela; Pinzari, Flavia; Payne, Gary A.; Fabbri, Anna A.; Fanelli, Corrado

    2012-01-01

    In filamentous fungi, peroxisomes are crucial for the primary metabolism and play a pivotal role in the formation of some secondary metabolites. Further, peroxisomes are important site for fatty acids β-oxidation, the formation of reactive oxygen species and for their scavenging through a complex of antioxidant activities. Oxidative stress is involved in different metabolic events in all organisms and it occurs during oxidative processes within the cell, including peroxisomal β-oxidation of fatty acids. In Aspergillus flavus, an unbalance towards an hyper-oxidant status into the cell is a prerequisite for the onset of aflatoxin biosynthesis. In our preliminary results, the use of bezafibrate, inducer of both peroxisomal β-oxidation and peroxisome proliferation in mammals, significantly enhanced the expression of pex11 and foxA and stimulated aflatoxin synthesis in A. flavus. This suggests the existence of a correlation among peroxisome proliferation, fatty acids β-oxidation and aflatoxin biosynthesis. To investigate this correlation, A. flavus was transformed with a vector containing P33, a gene from Cymbidium ringspot virus able to induce peroxisome proliferation, under the control of the promoter of the Cu,Zn-sod gene of A. flavus. This transcriptional control closely relates the onset of the antioxidant response to ROS increase, with the proliferation of peroxisomes in A. flavus. The AfP33 transformant strain show an up-regulation of lipid metabolism and an higher content of both intracellular ROS and some oxylipins. The combined presence of a higher amount of substrates (fatty acids-derived), an hyper-oxidant cell environment and of hormone-like signals (oxylipins) enhances the synthesis of aflatoxins in the AfP33 strain. The results obtained demonstrated a close link between peroxisome metabolism and aflatoxin synthesis. PMID:23094106

  3. Autoxidated linolenic acid inhibits aflatoxin biosynthesis in Aspergillus flavus via oxylipin species.

    PubMed

    Yan, Shijuan; Liang, Yating; Zhang, Jindan; Chen, Zhuang; Liu, Chun-Ming

    2015-08-01

    Aflatoxins produced by Aspergillus species are among the most toxic and carcinogenic compounds in nature. Although it has been known for a long time that seeds with high oil content are more susceptible to aflatoxin contamination, the role of fatty acids in aflatoxin biosynthesis remains controversial. Here we demonstrate in A. flavus that both the saturated stearic acid (C18:0) and the polyunsaturated linolenic acid (C18:3) promoted aflatoxin production, while C18:3, but not C18:0, inhibited aflatoxin biosynthesis after exposure to air for several hours. Further experiments showed that autoxidated C18:3 promoted mycelial growth, sporulation, and kojic acid production, but inhibited the expression of genes in the AF biosynthetic gene cluster. Mass spectrometry analyses of autoxidated C18:3 fractions that were able to inhibit aflatoxin biosynthesis led to the identification of multiple oxylipin species. These results may help to clarify the role of fatty acids in aflatoxin biosynthesis, and may explain why controversial results have been obtained for fatty acids in the past.

  4. Clustered Genes Involved in Cyclopiazonic Acid Production are Next to the Aflatoxin Biosynthesis Gene Cluster in Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclopiazonic acid (CPA), an indole-tetramic acid toxin, is produced by many species of Aspergillus and Penicillium. In addition to CPA Aspergillus flavus produces polyketide-derived carcinogenic aflatoxins (AFs). AF biosynthesis genes form a gene cluster in a subtelomeric region. Isolates of A. fla...

  5. Effects of nitrogen metabolism on growth and aflatoxin biosynthesis in Aspergillus flavus.

    PubMed

    Wang, Bin; Han, Xiaoyun; Bai, Youhuang; Lin, Zhenguo; Qiu, Mengguang; Nie, Xinyi; Wang, Sen; Zhang, Feng; Zhuang, Zhenhong; Yuan, Jun; Wang, Shihua

    2017-02-15

    Aflatoxins (AFs), produced mainly by Aspergillus flavus and Aspergillus parasiticus, are strongly toxic and carcinogenic. Here, we showed that glutamine is the optimal nitrogen source for AF-production in A. flavus grown in Czapek Dox medium. Additionally, 4mM glutamine was the threshold for high production of aflatoxin B1. However, no significant impact of glutamine synthetase inhibitor was detected for on AF biosynthesis. In contrast, rapamycin could significantly suppress the glutamine inducing effect on AFs production, simultaneously inhibiting the fungal growth and conidiation. To identify the genes and regulatory networks involved in AFs biosynthesis, especially concerning the nitrogen source metabolism pathway and the target of rapamycin (TOR) signaling pathway, we obtained transcriptomes for A. flavus under treatment of three nitrogen sources by RNA-sequencing. We identified 1429 differentially expressed genes. Through GO and KEGG pathway analyses, the relationship between nitrogen metabolism and AFs biosynthesis was revealed, and the effects of TOR inhibitor were confirmed. Additionally, the quantitative real-time PCR results verified the credibility and reliability of the RNA-seq data, and were consistent with the other experimental results. Our research laid the foundation for a primary study on the involvement of the nitrogen regulatory network and TOR signaling pathway in AF biosynthesis.

  6. HypC, the anthrone oxidase involved in aflatoxin biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on gene disruption and enzyme activity, hypC, an open reading frame in the pksA (aflC)/nor-1 (aflD) intergenic region in the aflatoxin biosynthesis cluster, encodes a 17 kDa oxidase that catalyzes the conversion of norsolorinic acid anthrone to norsolorinic acid....

  7. The DmtA methyltransferase contributes to Aspergillus flavus conidiation, sclerotial production, aflatoxin biosynthesis and virulence

    PubMed Central

    Yang, Kunlong; Liang, Linlin; Ran, Fanlei; Liu, Yinghang; Li, Zhenguo; Lan, Huahui; Gao, Peili; Zhuang, Zhenhong; Zhang, Feng; Nie, Xinyi; Kalayu Yirga, Shimuye; Wang, Shihua

    2016-01-01

    DNA methylation is essential for epigenetic regulation of gene transcription and development in many animals, plants and fungi. We investigated whether DNA methylation plays a role in the development and secondary metabolism of Aspergillus flavus, identified the DmtA methyltransferase from A. flavus, and produced a dmtA knock-out mutant by replacing the dmtA coding sequence with the pyrG selectable marker. The A. flavus dmtA null mutant lines produced white fluffy mycelium in liquid medium, and displayed a slightly flavescent conidial pigmentation compared with the normal yellow of the wild-type strain when grown on agar. The ΔdmtA lines exhibited decreased conidiation and aflatoxin (AF) biosynthesis, compared with the wild-type line, suggesting that the DmtA knock-out affected the transcriptional level of genes in the AF cluster. In particular, sclerotia development and host colonization were altered in the dmtA null mutants. Green fluorescent protein tagging at the C-terminus of DmtA showed that DmtA localized to the nucleus and cytoplasm. DNA methylation content measurements in the dmtA mutants revealed no widespread DNA methylation in the mutants or wild-type lines. Thus, our findings suggest that DmtA, apart from being a C-5 cytosine methyltransferase in A. flavus, contributes to asexual development, aflatoxin biosynthesis, sclerotial production and virulence. PMID:26979781

  8. The potential effects of Zataria multiflora Boiss essential oil on growth, aflatoxin production and transcription of aflatoxin biosynthesis pathway genes of toxigenic Aspergillus parasiticus.

    PubMed

    Yahyaraeyat, R; Khosravi, A R; Shahbazzadeh, D; Khalaj, V

    2013-01-01

    This study aims at evaluating the effects of Zataria multiflora (Z. multiflora) essential oil (EO) on growth, aflatoxin production and transcription of aflatoxin biosynthesis pathway genes. Total RNAs of Aspergillus parasiticus (A.parasiticus) ATCC56775 grown in yeast extract sucrose (YES) broth medium treated with Z. multiflora EO were subjected to reverse transcription- polymerase chain reaction (RT-PCR). Specific primers of nor-1, ver-1, omt-A and aflR genes were used. In parallel mycelial dry weight of samples were measured and all the media were assayed by high-pressure liquid chromatography (HPLC) for aflatoxinB1 (AFB1), aflatoxinB2 (AFB2), aflatoxinG1 (AFG1), aflatoxinG2 (AFG2) and aflatoxin total (AFTotal) production. The results showed that mycelial dry weight and aflatoxin production reduce in the presence of Z. multiflora EO (100 ppm) on day 5 of growth. It was found that the expression of nor-1, ver-1, omt-A and aflR genes was correlated with the ability of fungus to produce aflatoxins on day 5 in YES medium. RT-PCR showed that in the presence of Z.multiflora EO (100 ppm) nor-1, ver-1 and omtA genes expression was reduced. It seems that toxin production inhibitory effects of Z. multiflora EO on day 5 may be at the transcription level and this herb may cause reduction in aflatoxin biosynthesis pathway genes activity.

  9. Malonate as a precursor in the biosynthesis of aflatoxins.

    PubMed

    Gupta, S R; Prasanna, H R; Viswanathan, L; Venkitasurbramanian, T A

    1975-06-01

    Incorporation of [I-14C]acetate and [2-14C]malonate into aflatoxins by resting mycelia of Aspergillus parasiticus resuspended in different buffers was studied. A decrease in pH from 5-8 to 2-8, as well as addition of EDTA, markedly stimulated the incorporation of malonate but the effect on acetate incorporation was less pronounced. Mycelia took up comparatively more acetate than malonate, but more malonate (4-3%) entering mycelia was incorporated into aflatoxins than was acetate (1-6%). Furthermore, the addition of unlabelled acetate reduced the incorporation of label from [I-14C]acetate by 75% but from [2-14C]malonate by only 25%. These results suggest that malonate is an intermediate in aflatoxin synthesis and that is can be incorporated without prior conversion to acetate.

  10. Two distinct O-methyltransferases in aflatoxin biosynthesis.

    PubMed Central

    Yabe, K; Ando, Y; Hashimoto, J; Hamasaki, T

    1989-01-01

    The substances belonging to the sterigmatocystin group bear a close structural relationship to aflatoxins. When demethylsterigmatocystin (DMST) was fed to Aspergillus parasiticus NIAH-26, which endogenously produces neither aflatoxins nor precursors in YES medium, aflatoxins B1 and G1 were produced. When dihydrodemethylsterigmatocystin (DHDMST) was fed to this mutant, aflatoxins B2 and G2 were produced. Results of the cell-free experiment with S-adenosyl-[methyl-3H]methionine showed that first the C-6-OH groups of DMST and DHDMST are methylated to produce sterigmatocystin and dihydrosterigmatocystin (O-methyltransferase I) and then the C-7-OH groups are methylated to produce O-methylsterigmatocystin (OMST) and dihydro-O-methylsterigmatocystin (DHOMST) (O-methyltransferase II). However, no methyltransferase activity was observed when either OMST, DHOMST, 5,6-dimethoxysterigmatocystin, 5-methoxysterigmatocystin, or sterigmatin was incubated with the cell extract. Treatment of the cell extract with N-ethylmaleimide inhibited O-methyltransferase I activity but not that of O-methyltransferase II. Furthermore, these O-methyltransferases were different in their protein molecules and were involved in both the reactions from DMST to OMST and DHDMST to DHOMST. The reactions described in this paper were not observed when the same mold had been cultured in YEP medium. Images PMID:2802602

  11. Monitoring of individual human exposure to aflatoxins (AF) and N-nitrosamines (NNO) by immunoassays

    SciTech Connect

    Wild, C.P.; Umbenhauer, D.; Chapot, B.; Montesano, R.

    1986-01-01

    Highly sensitive immunoassays have been used to quantitate aflatoxins (AF) and N-nitrosamines (NNO) in human body fluids and tissues, respectively. This approach was taken in order to quantitate environmental exposure to these agents at an individual level to facilitate the investigation of their role in the etiology of human cancer. In order to analyse AF in human urine, an immunopurification step has been developed by using AF-specific antibody bound to AH-Sepharose 4B gel in a small (4-ml gel volume) affinity column prior to enzyme-linked immunosorbent assay (ELISA). The ELISA can be used to quantitate aflatoxin B1 (AFB1) over the range 0.01 ng/ml to 10 ng/ml and the assay system has been validated by using human urine samples spiked with AFB1 over this concentration range. In addition, 29 urine samples from the Philippines have been analyzed and found to contain a range of levels from zero to 4.25 ng/ml AFB1 equivalent with a mean of 0.875 ng/ml. This compared with a mean of 0.066 ng/ml AFB1 equivalent in samples from France. Radioimmunoassay of O6-methyldeoxyguanosine (O6-medG) has been performed on human esophageal and cardiac stomach mucosal DNA from tissue samples obtained during surgery in Linxian County, People's Republic of China, an area of high risk for both esophageal and stomach cancer. Using the methodology described and having 1 mg of hydrolyzed DNA allows the detection of approximately 25 fmol O6medG per mg DNA.

  12. Adenylate Cyclase AcyA Regulates Development, Aflatoxin Biosynthesis and Fungal Virulence in Aspergillus flavus

    PubMed Central

    Yang, Kunlong; Qin, Qiuping; Liu, Yinghang; Zhang, Limei; Liang, Linlin; Lan, Huahui; Chen, Chihao; You, Yunchao; Zhang, Feng; Wang, Shihua

    2016-01-01

    Aspergillus flavus is one of the most important opportunistic pathogens of crops and animals. The carcinogenic mycotoxin, aflatoxins produced by this pathogen cause a health problem to human and animals. Since cyclic AMP signaling controls a range of physiological processes, like fungal development and infection when responding to extracellular stimuli in fungal pathogens, in this study, we investigated the function of adenylate cyclase, a core component of cAMP signaling, in aflatoxins biosynthesis and virulence on plant seeds in A. flavus. A gene replacement strategy was used to generate the deletion mutant of acyA that encodes the adenylate cyclase. Severe defects in fungal growth, sporulation and sclerotia formation were observed in the acyA deletion mutant. The defect in radical growth could be partially rescued by exogenous cAMP analog. The acyA mutant was also significantly reduced in aflatoxins production and virulence. Similar to the former studies in other fungi, The acyA mutant showed enhancing tolerance to oxidative stress, but more sensitive to heat stress. Overall, the pleiotropic defects of the acyA deletion mutant indicates that the cAMP-PKA pathway is involved in fungal development, aflatoxins biosynthesis and plant seed invasion in A. flavus. PMID:28066725

  13. The Aspergillus flavus Histone Acetyltransferase AflGcnE Regulates Morphogenesis, Aflatoxin Biosynthesis, and Pathogenicity

    PubMed Central

    Lan, Huahui; Sun, Ruilin; Fan, Kun; Yang, Kunlong; Zhang, Feng; Nie, Xin Y.; Wang, Xiunai; Zhuang, Zhenhong; Wang, Shihua

    2016-01-01

    Histone acetyltransferases (HATs) help regulate fungal development and the production of secondary metabolites. In this study, we determined that the HAT AflGcnE influenced morphogenesis and aflatoxin biosynthesis in Aspergillus flavus. We observed that AflGcnE localized to the nucleus and cytoplasm during the conidial production and germination stages, while it was located mainly in the nucleus during the hyphal development stage. Deletion of AflgcnE inhibited the growth of A. flavus and decreased the hydrophobicity of the cell surface. The ΔAflgcnE mutant exhibited a lack of asexual sporulation and was unable to generate sclerotia. Additionally, AflgcnE was required to maintain cell wall integrity and genotoxic stress responses. Importantly, the ΔAflgcnE mutant did not produce aflatoxins, which was consistent with a significant down-regulation of aflatoxin gene expression levels. Furthermore, our data revealed that AflgcnE is a pathogenicity factor required for colonizing maize seeds. In summary, we revealed that A. flavus AflGcnE is crucial for morphological development, aflatoxin biosynthesis, stress responses, and pathogenicity. Our findings help clarify the functional divergence of GcnE orthologs, and may provide a possible target for controlling A. flavus infections of agriculturally important crops. PMID:27625637

  14. Inhibitory Effect of Cinnamaldehyde, Citral, and Eugenol on Aflatoxin Biosynthetic Gene Expression and Aflatoxin B1 Biosynthesis in Aspergillus flavus.

    PubMed

    Liang, Dandan; Xing, Fuguo; Selvaraj, Jonathan Nimal; Liu, Xiao; Wang, Limin; Hua, Huijuan; Zhou, Lu; Zhao, Yueju; Wang, Yan; Liu, Yang

    2015-12-01

    In order to reveal the inhibitory effects of cinnamaldehyde, citral, and eugenol on aflatoxin biosynthesis, the expression levels of 5 key aflatoxin biosynthetic genes were evaluated by real-time PCR. Aspergillus flavus growth and AFB1 production were completely inhibited by 0.80 mmol/L of cinnamaldehyde and 2.80 mmol/L of citral. However, at lower concentration, cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L) significantly reduced AFB1 production with inhibition rate of 68.9%, 95.4%, and 41.8%, respectively, while no effect on fungal growth. Real-time PCR showed that the expressions of aflR, aflT, aflD, aflM, and aflP were down-regulated by cinnamaldehyde (0.40 mmol/L), eugenol (0.80 mmol/L), and citral (0.56 mmol/L). In the presence of cinnamaldehyde, AflM was highly down-regulated (average of 5963 folds), followed by aflP, aflR, aflD, and aflT with the average folds of 55, 18, 6.5, and 5.8, respectively. With 0.80 mmol/L of eugenol, aflP was highly down-regulated (average of 2061-folds), followed by aflM, aflR, aflD, and aflT with average of 138-, 15-, 5.2-, and 4.8-folds reduction, respectively. With 0.56 mmol/L of citral, aflT was completely inhibited, followed by aflM, aflP, aflR, and aflD with average of 257-, 29-, 3.5-, and 2.5-folds reduction, respectively. These results suggest that the reduction in AFB1 production by cinnamaldehyde, eugenol, and citral at low concentration may be due to the down-regulations of the transcription level of aflatoxin biosynthetic genes. Cinnamaldehyde and eugenol may be employed successfully as a good candidate in controlling of toxigenic fungi and subsequently contamination with aflatoxins in practice.

  15. Aflatoxin biosynthesis is a novel source of reactive oxygen species—a potential redox signal to initiate resistance to oxidative stress?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin biosynthesis in the filamentous fungus Aspergillus parasiticus involves a minimum of 21 enzymes, encoded by genes located in a 70 kb gene cluster. For aflatoxin biosynthesis to be completed, the required enzymes must be transported to specialized early and late endosomes called aflatoxisom...

  16. Aflatoxin

    MedlinePlus

    ... found in the following foods: Peanuts and peanut butter Tree nuts such as pecans Corn Wheat Oil ... foods that may contain aflatoxin. Peanuts and peanut butter are some of the most rigorously tested products ...

  17. Global Phosphoproteomic Analysis Reveals the Involvement of Phosphorylation in Aflatoxins Biosynthesis in the Pathogenic Fungus Aspergillus flavus

    PubMed Central

    Ren, Silin; Yang, Mingkun; Li, Yu; Zhang, Feng; Chen, Zhuo; Zhang, Jia; Yang, Guang; Yue, Yuewei; Li, Siting; Ge, Feng; Wang, Shihua

    2016-01-01

    Aspergillus flavus is a pathogenic fungus that produces toxic and carcinogenic aflatoxins and is the causative agent of aflatoxicosis. A growing body of evidence indicates that reversible phosphorylation plays important roles in regulating diverse functions in this pathogen. However, only a few phosphoproteins of this fungus have been identified, which hampers our understanding of the roles of phosphorylation in A. flavus. So we performed a global and site-specific phosphoproteomic analysis of A. flavus. A total of 598 high-confidence phosphorylation sites were identified in 283 phosphoproteins. The identified phosphoproteins were involved in various biological processes, including signal transduction and aflatoxins biosynthesis. Five identified phosphoproteins associated with MAPK signal transduction and aflatoxins biosynthesis were validated by immunoblotting using phospho-specific antibodies. Further functional studies revealed that phosphorylation of the MAP kinase kinase kinase Ste11 affected aflatoxins biosynthesis in A. flavus. Our data represent the results of the first global survey of protein phosphorylation in A. flavus and reveal previously unappreciated roles for phosphorylation in the regulation of aflatoxins production. The generated dataset can serve as an important resource for the functional analysis of protein phosphorylation in A. flavus and facilitate the elucidation of phosphorylated signaling networks in this pathogen. PMID:27667718

  18. Association with AflR in Endosomes Reveals New Functions for AflJ in Aflatoxin Biosynthesis

    PubMed Central

    Ehrlich, Kenneth C.; Mack, Brian M.; Wei, Qijian; Li, Ping; Roze, Ludmila V.; Dazzo, Frank; Cary, Jeffrey W.; Bhatnagar, Deepak; Linz, John E.

    2012-01-01

    Aflatoxins are the most potent naturally occurring carcinogens of fungal origin. Biosynthesis of aflatoxin involves the coordinated expression of more than 25 genes. The function of one gene in the aflatoxin gene cluster, aflJ, is not entirely understood but, because previous studies demonstrated a physical interaction between the Zn2Cys6 transcription factor AflR and AflJ, AflJ was proposed to act as a transcriptional co-activator. Image analysis revealed that, in the absence of aflJ in A. parasiticus, endosomes cluster within cells and near septa. AflJ fused to yellow fluorescent protein complemented the mutation in A. parasiticus ΔaflJ and localized mainly in endosomes. We found that AflJ co-localizes with AflR both in endosomes and in nuclei. Chromatin immunoprecipitation did not detect AflJ binding at known AflR DNA recognition sites suggesting that AflJ either does not bind to these sites or binds to them transiently. Based on these data, we hypothesize that AflJ assists in AflR transport to or from the nucleus, thus controlling the availability of AflR for transcriptional activation of aflatoxin biosynthesis cluster genes. AflJ may also assist in directing endosomes to the cytoplasmic membrane for aflatoxin export. PMID:23342682

  19. Effect of temperature and water activity on gene expression and aflatoxin biosynthesis in Aspergillus flavus on almond medium.

    PubMed

    Gallo, Antonia; Solfrizzo, Michele; Epifani, Filomena; Panzarini, Giuseppe; Perrone, Giancarlo

    2016-01-18

    Almonds are among the commodities at risk of aflatoxin contamination by Aspergillus flavus. Temperature and water activity are the two key determinants in pre and post-harvest environments influencing both the rate of fungal spoilage and aflatoxin production. Varying the combination of these parameters can completely inhibit or fully activate the biosynthesis of aflatoxin, so it is fundamental to know which combinations can control or be conducive to aflatoxin contamination. Little information is available about the influence of these parameters on aflatoxin production on almonds. The objective of this study was to determine the influence of different combinations of temperature (20 °C, 28 °C, and 37 °C) and water activity (0.90, 0.93, 0.96, 0.99 aw) on growth, aflatoxin B1 (AFB1) production and expression of the two regulatory genes, aflR and aflS, and two structural genes, aflD and aflO, of the aflatoxin biosynthetic cluster in A. flavus grown on an almond medium solidified with agar. Maximum accumulation of fungal biomass and AFB1 production was obtained at 28 °C and 0.96 aw; no fungal growth and AFB1 production were observed at 20 °C at the driest tested conditions (0.90 and 0.93 aw). At 20° and 37 °C AFB1 production was 70-90% lower or completely suppressed, depending on aw. Reverse transcriptase quantitative PCR showed that the two regulatory genes (aflR and aflS) were highly expressed at maximum (28 °C) and minimum (20 °C and 37 °C) AFB1 production. Conversely the two structural genes (aflD and aflO) were highly expressed only at maximum AFB1 production (28 °C and 0.96-0.99 aw). It seems that temperature acts as a key factor influencing aflatoxin production which is strictly correlated to the induction of expression of structural biosynthesis genes (aflD and aflO), but not to that of aflatoxin regulatory genes (aflR and aflS), whose functional products are most likely subordinated to other regulatory processes acting at post-translational level

  20. Use of Selected Essential Oils to Control Aflatoxin Contaminated Stored Cashew and Detection of Aflatoxin Biosynthesis Gene

    PubMed Central

    Abd El-Aziz, Abeer R. M.; Mahmoud, Mohamed A.; Al-Othman, Monira R.; Al-Gahtani, Munirah F.

    2015-01-01

    Aspergillus spp. associated with cashew from the regions of Riyadh, Dammam, and Abha were isolated and three different culture media were used to qualitatively measure aflatoxin production by Aspergillus via UV light (365 nm), which was expressed as positive or negative. The obtained data showed that six isolates of A. flavus and four isolates of A. parasiticus were positive for aflatoxin production, while all isolates of A. niger were negative. Five commercially essential oils (thyme, garlic, cinnamon, mint, and rosemary) were tested to determine their influence on growth and aflatoxin production in A. flavus and A. parasiticus by performing high-performance liquid chromatography (HPLC). The results showed that the tested essential oils caused highly significant inhibition of fungal growth and aflatoxin production in A. flavus and A. parasiticus. The extent of the inhibition of fungal growth and aflatoxin production was dependent on the type and concentration of essential oils applied. The results indicate that cinnamon and thyme oils show strong antimicrobial potential. PCR was used with four sets of primer pairs for nor-1, omt-1, ver-1, and aflR genes, enclosed in the aflatoxin biosynthetic pathway. The interpretation of the results revealed that PCR is a rapid and sensitive method. PMID:25705718

  1. Use of selected essential oils to control aflatoxin contaminated stored cashew and detection of aflatoxin biosynthesis gene.

    PubMed

    Abd El-Aziz, Abeer R M; Mahmoud, Mohamed A; Al-Othman, Monira R; Al-Gahtani, Munirah F

    2015-01-01

    Aspergillus spp. associated with cashew from the regions of Riyadh, Dammam, and Abha were isolated and three different culture media were used to qualitatively measure aflatoxin production by Aspergillus via UV light (365 nm), which was expressed as positive or negative. The obtained data showed that six isolates of A. flavus and four isolates of A. parasiticus were positive for aflatoxin production, while all isolates of A. niger were negative. Five commercially essential oils (thyme, garlic, cinnamon, mint, and rosemary) were tested to determine their influence on growth and aflatoxin production in A. flavus and A. parasiticus by performing high-performance liquid chromatography (HPLC). The results showed that the tested essential oils caused highly significant inhibition of fungal growth and aflatoxin production in A. flavus and A. parasiticus. The extent of the inhibition of fungal growth and aflatoxin production was dependent on the type and concentration of essential oils applied. The results indicate that cinnamon and thyme oils show strong antimicrobial potential. PCR was used with four sets of primer pairs for nor-1, omt-1, ver-1, and aflR genes, enclosed in the aflatoxin biosynthetic pathway. The interpretation of the results revealed that PCR is a rapid and sensitive method.

  2. Understanding Nonaflatoxigenicity of Aspergillus sojae: A Windfall of Aflatoxin Biosynthesis Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus section Flavi includes aflatoxin-producing and nonproducing fungi. A. sojae is unable to produce aflatoxins and is generally recognized as safe for food fermentation. However, because of its taxonomical relatedness to aflatoxin-producing A. parasiticus and A. flavus, it is necessary to...

  3. Production of M-/GM-group aflatoxins catalyzed by the OrdA enzyme in aflatoxin biosynthesis.

    PubMed

    Yabe, Kimiko; Chihaya, Naomi; Hatabayashi, Hidemi; Kito, Masako; Hoshino, Sachiko; Zeng, Hongmei; Cai, Jingjing; Nakajima, Hiromitsu

    2012-09-01

    Aspergillus parasiticus produces the minor aflatoxins M(1) (AFM(1)), M(2) (AFM(2)), GM(1) (AFGM(1)), and GM(2) (AFGM(2)), as well as the major aflatoxins B(1) (AFB(1)), B(2) (AFB(2)), G(1) (AFG(1)), and G(2) (AFG(2)). Feeding of A. parasiticus with aspertoxin (12c-hydroxyOMST) caused AFM(1) and AFGM(1), and cell-free experiments using the microsomal fraction of A. parasiticus and aspertoxin caused production of AFM(1), indicating that aspertoxin is a precursor of AFM(1) and AFGM(1). Feeding of the same fungus with O-methylsterigmatocystin (OMST) caused AFM(1) and AFGM(1) together with AFB(1) and AFG(1); feeding with dihydroOMST (DHOMST) caused AFM(2) and AFGM(2) together with AFB(2) and AFG(2). Incubation of either the microsomal fraction or OrdA enzyme-expressing yeast with OMST caused production of aspertoxin together with AFM(1) and AFB(1). These results demonstrated that the OrdA enzyme catalyzes both 12c-hydroxylation reaction from OMST to aspertoxin and the successive reaction from aspertoxin to AFM(1). In contrast, feeding of the fungus with AFB(1) did not produce any AFM(1), demonstrating that M-/GM-aflatoxins are not produced from B-/G-aflatoxins. Furthermore, AFM(1) together with AFB(1) and AFG(1) was also produced from 11-hydroxyOMST (HOMST) in feeding experiment of A. parasiticus, whereas no aflatoxins were produced when used the ordA deletion mutant. These results demonstrated that OrdA enzyme can also catalyze 12c-hydroxylation of HOMST to produce 11-hydroxyaspertoxin, which serves as a precursor for the production of AFM(1) and AFGM(1). The same pathway may work for the production of AFM(2) and AFGM(2) from DHOMST and dihydroHOMST through the formation of dihydroaspertoxin and dihydro-11-hydroxyaspertoxin, respectively.

  4. Dillapiol and Apiol as specific inhibitors of the biosynthesis of aflatoxin G1 in Aspergillus parasiticus.

    PubMed

    Razzaghi-Abyaneh, Mehdi; Yoshinari, Tomoya; Shams-Ghahfarokhi, Masoomeh; Rezaee, Mohammad-Bagher; Nagasawa, Hiromichi; Sakuda, Shohei

    2007-09-01

    Dillapiol was isolated from the essential oil of dill as a specific inhibitor of aflatoxin G1 production. It inhibited aflatoxin G1 production by Aspergillus parasiticus with an IC50 value of 0.15 microM without inhibiting aflatoxin B1 production or fungal growth. Apiol and myristicin, congeners of dillapiol, showed similar activity with IC50 values of 0.24 and 3.5 microM, respectively.

  5. The potential role of oxidative stress in Aspergillus flavus survivability and aflatoxin biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination of food and feed occurs due to growth of Aspergillus flavus. This poses a serious health risk because of aflatoxin’s toxic and carcinogenic properties which negatively impact human and livestock health. Colonization and subsequent aflatoxin production by A. flavus is typicall...

  6. Sequence breakpoints in the aflatoxin biosynthesis gene cluster and flanking regions in nonaflatoxigenic Aspergillus flavus isolates.

    PubMed

    Chang, Perng-Kuang; Horn, Bruce W; Dorner, Joe W

    2005-11-01

    Aspergillus flavus populations are genetically diverse. Isolates that produce either, neither, or both aflatoxins and cyclopiazonic acid (CPA) are present in the field. We investigated defects in the aflatoxin gene cluster in 38 nonaflatoxigenic A. flavus isolates collected from southern United States. PCR assays using aflatoxin-gene-specific primers grouped these isolates into eight (A-H) deletion patterns. Patterns C, E, G, and H, which contain 40 kb deletions, were examined for their sequence breakpoints. Pattern C has one breakpoint in the cypA 3' untranslated region (UTR) and another in the verA coding region. Pattern E has a breakpoint in the amdA coding region and another in the ver1 5'UTR. Pattern G contains a deletion identical to the one found in pattern C and has another deletion that extends from the cypA coding region to one end of the chromosome as suggested by the presence of telomeric sequence repeats, CCCTAATGTTGA. Pattern H has a deletion of the entire aflatoxin gene cluster from the hexA coding region in the sugar utilization gene cluster to the telomeric region. Thus, deletions in the aflatoxin gene cluster among A. flavus isolates are not rare, and the patterns appear to be diverse. Genetic drift may be a driving force that is responsible for the loss of the entire aflatoxin gene cluster in nonaflatoxigenic A. flavus isolates when aflatoxins have lost their adaptive value in nature.

  7. Structural and functional analysis of the nor-1 gene involved in the biosynthesis of aflatoxins by Aspergillus parasiticus.

    PubMed Central

    Trail, F; Chang, P K; Cary, J; Linz, J E

    1994-01-01

    The nor-1 gene was cloned previously by complementation of a mutation (nor-1) in Aspergillus parasiticus SU-1 which blocked aflatoxin B1 biosynthesis, resulting in the accumulation of norsolorinic acid (NA). In this study, the nucleotide sequences of the cDNA and genomic DNA clones encompassing the coding region of the nor-1 gene were determined. The transcription initiation and polyadenylation sites of nor-1 were located by primer extension and RNase protection analyses and by comparison of the nucleotide sequences of the nor-1 genomic and cDNA clones. A plasmid, pNA51-82, was created for one-step disruption of the nor-1 gene by inserting a functional copy of the nitrate reductase (niaD) gene from A. parasiticus into the coding region of the nor-1 gene. Transformation of A. parasiticus NR-3 (niaD Afl+) with pNA51-82 resulted in niaD+ transformants that accumulated NA and produced reduced levels of aflatoxin as determined by thin-layer chromatography and enzyme-linked immunosorbent assay analyses of extracts from mycelia and the growth medium. Southern analysis of genomic DNA isolated from the NA-accumulating transformants indicated that the wild-type nor-1 gene in the chromosome had been replaced by the nonfunctional allele carried on pNA51-82. This recombinational inactivation event provides direct evidence that the nor-1 gene is functionally involved in aflatoxin biosynthesis. Comparison of the predicted nor-1 amino acid sequence with sequences in the GenBank and EMBL databases suggested that the protein is a member of the family of short-chain alcohol dehydrogenases, consistent with its proposed function as a keto reductase. Images PMID:7993094

  8. Suppression of Aflatoxin Biosynthesis in Aspergillus flavus by 2-Phenylethanol Is Associated with Stimulated Growth and Decreased Degradation of Branched-Chain Amino Acids.

    PubMed

    Chang, Perng-Kuang; Hua, Sui Sheng T; Sarreal, Siov Bouy L; Li, Robert W

    2015-09-24

    The saprophytic soil fungus Aspergillus flavus infects crops and produces aflatoxin. Pichia anomala, which is a biocontrol yeast and produces the major volatile 2-phenylethanol (2-PE), is able to reduce growth of A. flavus and aflatoxin production when applied onto pistachio trees. High levels of 2-PE are lethal to A. flavus and other fungi. However, at low levels, the underlying mechanism of 2-PE to inhibit aflatoxin production remains unclear. In this study, we characterized the temporal transcriptome response of A. flavus to 2-PE at a subinhibitory level (1 μL/mL) using RNA-Seq technology and bioinformatics tools. The treatment during the entire 72 h experimental period resulted in 131 of the total A. flavus 13,485 genes to be significantly impacted, of which 82 genes exhibited decreased expression. They included those encoding conidiation proteins and involved in cyclopiazonic acid biosynthesis. All genes in the aflatoxin gene cluster were also significantly decreased during the first 48 h treatment. Gene Ontology (GO) analyses showed that biological processes with GO terms related to catabolism of propionate and branched-chain amino acids (valine, leucine and isoleucine) were significantly enriched in the down-regulated gene group, while those associated with ribosome biogenesis, translation, and biosynthesis of α-amino acids OPEN ACCESS Toxins 2015, 7 3888 were over-represented among the up-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that metabolic pathways negatively impacted among the down-regulated genes parallel to those active at 30 °C, a condition conducive to aflatoxin biosynthesis. In contrast, metabolic pathways positively related to the up-regulated gene group resembled those at 37 °C, which favors rapid fungal growth and is inhibitory to aflatoxin biosynthesis. The results showed that 2-PE at a low level stimulated active growth of A. flavus but concomitantly rendered decreased activities in

  9. Cinnamaldehyde inhibits fungal growth and aflatoxin B1 biosynthesis by modulating the oxidative stress response of Aspergillus flavus.

    PubMed

    Sun, Qi; Shang, Bo; Wang, Ling; Lu, Zhisong; Liu, Yang

    2016-02-01

    Cinnamaldehyde (CIN) is a promising natural preservative and generally recognized as safe for commodities as well as consumers. In this work, the antifungal effects of CIN on Aspergillus flavus were evaluated both in solid and in liquid culture conditions. Our results indicated that CIN effectively inhibited radial growth, spore production, mycelium formation, and aflatoxin B1 biosynthesis by A. flavus in a dose-dependent manner. At the concentration of 104 mg L(-1), CIN exposure was able to completely inhibit fungal growth as well as aflatoxin B1 production. Furthermore, the inhibitory activities of CIN were closely connected with the treatment period and the tested fungal species. Compared with the control strains, CIN dose dependently changed the morphology and ultrastructure of mycelium in different degree. Especially, the reduction of hydrogen peroxide was considered to follow the destruction of mitochondrial. Meanwhile, CIN significantly cut the levels of lipid peroxidation and reduced glutathione. The activity of total superoxide dismutase was significantly inhibited after CIN treatment at the end of incubation, whereas the activities of catalase and glutathione peroxidase were opposite. These results indicated that the inhibitory effect of CIN could attribute to oxidative stress alleviation possibly induced by modifications of cellular structure as well as redox status.

  10. Regulation of aflatoxin biosynthesis: effect of glucose on activities of various glycolytic enzymes.

    PubMed Central

    Buchanan, R L; Lewis, D F

    1984-01-01

    Catabolism of carbohydrates has been implicated in the regulation of aflatoxin synthesis. To characterize this effect further, the activities of various enzymes associated with glucose catabolism were determined in Aspergillus parasiticus organisms that were initially cultured in peptone-mineral salts medium and then transferred to glucose-mineral salts and peptone-mineral salts media. After an initial increase in activity, the levels of glucose 6-phosphate dehydrogenase, mannitol dehydrogenase, and malate dehydrogenase were lowered in the presence of glucose. Phosphofructokinase activity was greater in the peptone-grown mycelium, but fructose diphosphatase was largely unaffected by carbon source. Likewise, carbon source had relatively little effect on the activities of pyruvate kinase, malic enzyme, isocitrate-NADP dehydrogenase, and isocitrate-NAD dehydrogenase. The results suggest that glucose may, in part, regulate aflatoxin synthesis via a carbon catabolite repression of NADPH-generating and tricarboxylic acid cycle enzymes. PMID:6091545

  11. Microbe-Mediated Control of Mycotoxigenic Grain Fungi in Stored Rice with Focus on Aflatoxin Biodegradation and Biosynthesis Inhibition

    PubMed Central

    Mannaa, Mohamed

    2016-01-01

    Rice contaminated with fungal species during storage is not only of poor quality and low economic value, but may also have harmful effects on human and animal health. The predominant fungal species isolated from rice grains during storage belong to the genera Aspergillus and Penicillium. Some of these fungal species produce mycotoxins; they are responsible for adverse health effects in humans and animals, particularly Aspergillus flavus, which produces the extremely carcinogenic aflatoxins. Not surprisingly, there have been numerous attempts to devise safety procedure for the control of such harmful fungi and production of mycotoxins, including aflatoxins. This review provides information about fungal and mycotoxin contamination of stored rice grains, and microbe-based (biological) strategies to control grain fungi and mycotoxins. The latter will include information regarding attempts undertaken for mycotoxin (especially aflatoxin) bio-detoxification and microbial interference with the aflatoxin-biosynthetic pathway in the toxin-producing fungi. PMID:27433116

  12. Sulforaphane, a cancer chemopreventive agent, induces pathways associated with membrane biosynthesis in response to tissue damage by aflatoxin B{sub 1}

    SciTech Connect

    Techapiesancharoenkij, Nirachara; Fiala, Jeannette L.A.; Navasumrit, Panida; Croy, Robert G.; Wogan, Gerald N.; Groopman, John D.; Ruchirawat, Mathuros; Essigmann, John M.

    2015-01-01

    Aflatoxin B{sub 1} (AFB{sub 1}) is one of the major risk factors for liver cancer globally. A recent study showed that sulforaphane (SF), a potent inducer of phase II enzymes that occurs naturally in widely consumed vegetables, effectively induces hepatic glutathione S-transferases (GSTs) and reduces levels of hepatic AFB{sub 1}-DNA adducts in AFB{sub 1}-exposed Sprague Dawley rats. The present study characterized the effects of SF pre-treatment on global gene expression in the livers of similarly treated male rats. Combined treatment with AFB{sub 1} and SF caused reprogramming of a network of genes involved in signal transduction and transcription. Changes in gene regulation were observable 4 h after AFB{sub 1} administration in SF-pretreated animals and may reflect regeneration of cells in the wake of AFB{sub 1}-induced hepatotoxicity. At 24 h after AFB{sub 1} administration, significant induction of genes that play roles in cellular lipid metabolism and acetyl-CoA biosynthesis was detected in SF-pretreated AFB{sub 1}-dosed rats. Induction of this group of genes may indicate a metabolic shift toward glycolysis and fatty acid synthesis to generate and maintain pools of intermediate molecules required for tissue repair, cell growth and compensatory hepatic cell proliferation. Collectively, gene expression data from this study provide insights into molecular mechanisms underlying the protective effects of SF against AFB{sub 1} hepatotoxicity and hepatocarcinogenicity, in addition to the chemopreventive activity of this compound as a GST inducer. - Highlights: • This study revealed sulforaphane (SF)-deregulated gene sets in aflatoxin B{sub 1} (AFB{sub 1})-treated rat livers. • SF redirects biochemical networks toward lipid biosynthesis in AFB{sub 1}-dosed rats. • SF enhanced gene sets that would be expected to favor cell repair and regeneration.

  13. Structure and biosynthesis of fimsbactins A-F, siderophores from Acinetobacter baumannii and Acinetobacter baylyi.

    PubMed

    Proschak, Anna; Lubuta, Patrice; Grün, Peter; Löhr, Frank; Wilharm, Gottfried; De Berardinis, Veronique; Bode, Helge B

    2013-03-18

    Novel chatechol/hydroxamate siderophores (named "fimsbactins") were identified in Acinetobacter baumannii ATCC 17978 and Acinetobacter baylyi ADP1. The major compound, fimsbactin A, was isolated from low-iron cultures of A. baylyi ADP1, and its chemical structure was elucidated by mass spectrometry, and detailed (1)H, (13)C and (15)N NMR spectroscopy. From inverse feeding experiments following HPLC-MS analysis, the structures of five additional derivatives were elucidated. The gene cluster encoding the fimsbactin synthetase (fbs) was identified in both genomes, and mutants in fbs genes in A. baylyi were analyzed, thus allowing prediction of the fimsbactin biosynthesis pathway.

  14. Genetic Analysis of the Aspergillus flavus Vegetative Compatibility Group to Which a Biological Control Agent That Limits Aflatoxin Contamination in U.S. Crops Belongs.

    PubMed

    Grubisha, Lisa C; Cotty, Peter J

    2015-09-01

    Some filamentous fungi in Aspergillus section Flavi produce carcinogenic secondary compounds called aflatoxins. Aflatoxin contamination is routinely managed in commercial agriculture with strains of Aspergillus flavus that do not produce aflatoxins. These non-aflatoxin-producing strains competitively exclude aflatoxin producers and reshape fungal communities so that strains with the aflatoxin-producing phenotype are less frequent. This study evaluated the genetic variation within naturally occurring atoxigenic A. flavus strains from the endemic vegetative compatibility group (VCG) YV36. AF36 is a strain of VCG YV36 and was the first fungus used in agriculture for aflatoxin management. Genetic analyses based on mating-type loci, 21 microsatellite loci, and a single nucleotide polymorphism (SNP) in the aflC gene were applied to a set of 237 YV36 isolates collected from 1990 through 2005 from desert legumes and untreated fields and from fields previously treated with AF36 across the southern United States. One haplotype dominated across time and space. No recombination with strains belonging to VCGs other than YV36 was detected. All YV36 isolates carried the SNP in aflC that prevents aflatoxin biosynthesis and the mat1-2 idiomorph at the mating-type locus. These results suggest that VCG YV36 has a clonal population structure maintained across both time and space. These results demonstrate the genetic stability of atoxigenic strains belonging to a broadly distributed endemic VCG in both untreated populations and populations where the short-term frequency of VCG YV36 has increased due to applications of a strain used to competitively exclude aflatoxin producers. This work supports the hypothesis that strains of this VCG are not involved in routine genetic exchange with aflatoxin-producing strains.

  15. Genetic Analysis of the Aspergillus flavus Vegetative Compatibility Group to Which a Biological Control Agent That Limits Aflatoxin Contamination in U.S. Crops Belongs

    PubMed Central

    Cotty, Peter J.

    2015-01-01

    Some filamentous fungi in Aspergillus section Flavi produce carcinogenic secondary compounds called aflatoxins. Aflatoxin contamination is routinely managed in commercial agriculture with strains of Aspergillus flavus that do not produce aflatoxins. These non-aflatoxin-producing strains competitively exclude aflatoxin producers and reshape fungal communities so that strains with the aflatoxin-producing phenotype are less frequent. This study evaluated the genetic variation within naturally occurring atoxigenic A. flavus strains from the endemic vegetative compatibility group (VCG) YV36. AF36 is a strain of VCG YV36 and was the first fungus used in agriculture for aflatoxin management. Genetic analyses based on mating-type loci, 21 microsatellite loci, and a single nucleotide polymorphism (SNP) in the aflC gene were applied to a set of 237 YV36 isolates collected from 1990 through 2005 from desert legumes and untreated fields and from fields previously treated with AF36 across the southern United States. One haplotype dominated across time and space. No recombination with strains belonging to VCGs other than YV36 was detected. All YV36 isolates carried the SNP in aflC that prevents aflatoxin biosynthesis and the mat1-2 idiomorph at the mating-type locus. These results suggest that VCG YV36 has a clonal population structure maintained across both time and space. These results demonstrate the genetic stability of atoxigenic strains belonging to a broadly distributed endemic VCG in both untreated populations and populations where the short-term frequency of VCG YV36 has increased due to applications of a strain used to competitively exclude aflatoxin producers. This work supports the hypothesis that strains of this VCG are not involved in routine genetic exchange with aflatoxin-producing strains. PMID:26092465

  16. Suppression of spore germination and aflatoxin biosynthesis in Aspergillus parasiticus during and after exposure to high levels of phosphine.

    PubMed

    Antonacci, L; Salvat, A E; Faifer, G C; Godoy, H M

    1999-01-01

    Agar cultures of toxigenic Aspergillus parasiticus NRRL 2999 were exposed to phosphine (PH3), in levels ranging from 0 to 2000 ppm (vol/vol). It was found that with PH3 concentrations of 400 ppm or higher the growth of the fungus was totally arrested. When PH3 was vented and the agar plates were exposed to open air, 100% of the initial CFU developed into fully grown colonies after PH3 levels below 300 ppm, but at higher PH3 concentrations only 50% of the colonies developed. The same strain of A. parasiticus was inoculated into high moisture corn under conditions highly favorable for aflatoxin production, and it was exposed to a range of PH3 levels. After exposure to 500 ppm PH3, both fungal growth and aflatoxin synthesis resumed shortly after elimination of the toxic gas, but after exposure to PH3 levels of 1000 ppm and higher, the physical appearance of the contaminated corn was remarkably changed, showing reduced mycelial growth and almost complete absence of green pigmentation. In addition, aflatoxin synthesis was totally absent for the remainder of the experiment (20 days). These results strongly suggest that exposure to PH3 levels of 1000 ppm or higher could bring about persistent metabolic changes in surviving Aspergillus organisms.

  17. Phytochemicals reduce aflatoxin-induced toxicity in chicken embryos

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins (AF) are toxic metabolites produced by molds, Aspergillus flavus and Aspergillus parasicitus, which frequently contaminate chicken feed ingredients. Ingestion of AF-contaminated feed by chickens leads to deleterious effects, including decreased chicken performance and reduced egg producti...

  18. Spiroethers of German chamomile inhibit production of aflatoxin G and trichothecene mycotoxin by inhibiting cytochrome P450 monooxygenases involved in their biosynthesis.

    PubMed

    Yoshinari, Tomoya; Yaguchi, Atsushi; Takahashi-Ando, Naoko; Kimura, Makoto; Takahashi, Haruo; Nakajima, Takashi; Sugita-Konishi, Yoshiko; Nagasawa, Hiromichi; Sakuda, Shohei

    2008-07-01

    The essential oil of German chamomile showed specific inhibition toward aflatoxin G(1) (AFG(1)) production, and (E)- and (Z)-spiroethers were isolated as the active compounds from the oil. The (E)- and (Z)-spiroethers inhibited AFG(1) production of Aspergillus parasiticus with inhibitory concentration 50% (IC(50)) values of 2.8 and 20.8 microM, respectively, without inhibiting fungal growth. Results of an O-methylsterigmatocystin (OMST) conversion study indicated that the spiroethers specifically inhibited the OMST to AFG(1) pathway. A cytochrome P450 monooxygenase, CYPA, is known as an essential enzyme for this pathway. Because CYPA has homology with TRI4, a key enzyme catalyzing early steps in the biosynthesis of trichothecenes, the inhibitory actions of the two spiroethers against TRI4 reactions and 3-acetyldeoxynivalenol (3-ADON) production were tested. (E)- and (Z)-spiroethers inhibited the enzymatic activity of TRI4 dose-dependently and interfered with 3-ADON production by Fusarium graminearum, with IC(50) values of 27.1 and 103 microM, respectively. Our results suggest that the spiroethers inhibited AFG(1) and 3-ADON production by inhibiting CYPA and TRI4, respectively.

  19. Quantitative correlation of aflatoxin biomarker with dietary intake of aflatoxin in Tanzanian children.

    PubMed

    Routledge, Michael N; Kimanya, Martin E; Shirima, Candida P; Wild, Christopher P; Gong, Yun Yun

    2014-08-01

    The association between aflatoxin intake from maize-based weaning food and aflatoxin albumin adducts (AF-alb) was investigated in 148 Tanzanian children aged between 12 and 22 months, at 2 visits 6 months apart. At the first visit (storage season) there was a significant correlation at the individual level between AF-alb (geometric mean 43.2 pg/mg albumin) and aflatoxin intake (geometric mean 81.7 ng/kg b.w./d) through maize-based weaning food (r = 0.51, p < 0.01). Overall, this correlation was r = 0.43 (p < 0.01). The AF-alb level in weaning-age children in Tanzania closely reflects aflatoxin intake from maize in weaning food. Exposure levels suggest children may be at risk from aflatoxin associated health effects.

  20. Aflatoxins in black tea in Iran.

    PubMed

    Pouretedal, Zohreh; Mazaheri, Mansooreh

    2013-01-01

    Aflatoxins (AFs) are highly toxic, and carcinogenic secondary fungal metabolites and have been detected in various food commodities. In this regard, 40 black tea samples including domestic and imported black tea were analysed for aflatoxin contamination by high-performance liquid chromatography using a post-column derivatisation procedure (Kobra cell) with fluorescence detection. Samples were randomly collected in 2010 from Tehran markets. The results revealed that 30 among 40 samples were contaminated with aflatoxins (27.5% of the total). Mean AFB1 content was 10.0 ng/g and mean of aflatoxin total was 12.07 ng/g for the 11 contaminated samples.

  1. Regulation of aflatoxin biosynthesis and branched-chain amino acids metabolism in Aspergillus flavus by 2-phenylethanol reveal biocontrol mechanism of Pichia anomala

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pichia anomala WRL-076 is a biocontrol yeast which has been shown to inhibit growth and aflatoxin production of A. flavus. Using the SPME-GC/MS analysis we identified that the volatile, 2-phenylethanol (2-PE) produced by this yeast and demonstrated that the compound inhibited aflatoxin production. W...

  2. Non-linear relationships between aflatoxin B1 levels and the biological response of monkey kidney vero cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin (AF)-producing fungi contaminate food and feed during preharvest, storage and processing periods. Once consumed, AF accumulates in tissues, causing illnesses in animals and humans. At least 20 different types of AFs have been identified, and of these, aflatoxin B1 (AFB1) is the most ubiqui...

  3. Degeneration of aflatoxin gene cluster in Aspergillus flavus from Africa and North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is the primary causal agent of food and feed contamination with the toxic fungal metabolites aflatoxins. Aflatoxin-producing potential of A. flavus is known to vary among isolates. The genes involved in aflatoxin biosynthesis are clustered together and the order of genes within th...

  4. A Caleosin-Like Protein with Peroxygenase Activity Mediates Aspergillus flavus Development, Aflatoxin Accumulation, and Seed Infection

    PubMed Central

    Almousally, Ibrahem; Shaban, Mouhnad; Blee, Elizabeth

    2015-01-01

    Caleosins are a small family of calcium-binding proteins endowed with peroxygenase activity in plants. Caleosin-like genes are present in fungi; however, their functions have not been reported yet. In this work, we identify a plant caleosin-like protein in Aspergillus flavus that is highly expressed during the early stages of spore germination. A recombinant purified 32-kDa caleosin-like protein supported peroxygenase activities, including co-oxidation reactions and reduction of polyunsaturated fatty acid hydroperoxides. Deletion of the caleosin gene prevented fungal development. Alternatively, silencing of the gene led to the increased accumulation of endogenous polyunsaturated fatty acid hydroperoxides and antioxidant activities but to a reduction of fungal growth and conidium formation. Two key genes of the aflatoxin biosynthesis pathway, aflR and aflD, were downregulated in the strains in which A. flavus PXG (AfPXG) was silenced, leading to reduced aflatoxin B1 production in vitro. Application of caleosin/peroxygenase-derived oxylipins restored the wild-type phenotype in the strains in which AfPXG was silenced. PXG-deficient A. flavus strains were severely compromised in their capacity to infect maize seeds and to produce aflatoxin. Our results uncover a new branch of the fungal oxylipin pathway and may lead to the development of novel targets for controlling fungal disease. PMID:26116672

  5. PCR detection of aflatoxin producing fungi and its limitations.

    PubMed

    Levin, Robert E

    2012-05-01

    Unlike bacterial toxins that are primarily peptides and are therefore encoded by a single gene, fungal toxins such as the aflatoxins are multi-ring structures and therefore require a sequence of structural genes for their biological synthesis. There is therefore no specific PCR for any one of the four biologically produced aflatoxins. Unfortunately, the structural genes presently in use for PCR detection of aflatoxin producing fungi are also involved in the synthesis of other fungal toxins such as sterigmatocystin by Aspergillus versicolor and Aspergillus nidulans and therefore lack absolute specificity for aflatoxin producing fungi (Table 1). In addition, the genomic presence of several structural genes involved in aflatoxin biosynthesis does not guarantee the production of aflatoxin by all isolates of Aspergillus flavus and Aspergillus parasiticus. The most widely used DNA target regions for discriminating Aspergillus species are those of the rDNA complex, mainly the internal transcribed spacer regions 1 and 2 (ITS1 and ITS2) and the variable regions in the 5'-end of the 28S rRNA gene. Since these sequence regions are unrelated to the structural genes involved in aflatoxin biosynthesis there successful amplification can be used for species identification but do not confirm aflatoxin production. This review therefore presents the various approaches and limitations in the use of the PCR in attempting to detect aflatoxin producing fungi.

  6. Potential of lactic acid bacteria in aflatoxin risk mitigation.

    PubMed

    Ahlberg, Sara H; Joutsjoki, Vesa; Korhonen, Hannu J

    2015-08-17

    Aflatoxins (AF) are ubiquitous mycotoxins contaminating food and feed. Consumption of contaminated food and feed can cause a severe health risk to humans and animals. A novel biological method could reduce the health risks of aflatoxins through inhibiting mold growth and binding aflatoxins. Lactic acid bacteria (LAB) are commonly used in fermented food production. LAB are known to inhibit mold growth and, to some extent, to bind aflatoxins in different matrices. Reduced mold growth and aflatoxin production may be caused by competition for nutrients between bacterial cells and fungi. Most likely, binding of aflatoxins depends on environmental conditions and is strain-specific. Killed bacteria cells possess consistently better binding abilities for aflatoxin B1 (AFB1) than viable cells. Lactobacilli especially are relatively well studied and provide noticeable possibilities in binding of aflatoxin B1 and M1 in food. It seems that binding is reversible and that bound aflatoxins are released later on (Haskard et al., 2001; Peltonen et al., 2001). This literature review suggests that novel biological methods, such as lactic acid bacteria, show potential in mitigating toxic effects of aflatoxins in food and feed.

  7. Sexuality generates diversity in the aflatoxin gene cluster: evidence on a global scale

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The worldwide costs associated with aflatoxin monitoring and crop losses are in the hundreds of millions of dollars. Aflatoxins also account for considerable health risks, even in countries where food contamination is regulated. Aspergillus flavus and A. parasiticus are the most common agents of af...

  8. Conversion of 11-hydroxy-O-methylsterigmatocystin to aflatoxin G1 in Aspergillus parasiticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In aflatoxin biosynthesis, aflatoxins G1 (AFG1) and B1 (AFB1) are independently produced from a common precursor, O-methylsterigmatocystin (OMST). Recently, 11-hydroxy-O-methylsterigmatocystin (HOMST) was identified as a later precursor involved in the conversion of OMST to AFB1. However, the invo...

  9. Regulation of the aflatoxin-like toxin dothistromin by AflJ

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biosynthesis by Aspergillus parasiticus of aflatoxin, one of the most potent known naturally occurring carcinogens, requires the activity of two regulatory proteins, AflR and AflJ, which are encoded by divergently transcribed genes within the aflatoxin gene cluster. Although the Zn2Cys6 transcriptio...

  10. Distribution of aflatoxins in product and by-products during glucose production from contaminated corn.

    PubMed

    Aly, Soher E

    2002-10-01

    Aflatoxins are known to be hepatotoxic, carcinogenic, and teratogenic. A positive correlation has been established between the consumption of aflatoxin-contaminated foods and the increased incidence of liver cancer worldwide. A survey of Egyptian corn and corn-based products and by-products shows that the majority of the samples had higher limits of aflatoxin. We have conducted experiments to determine the fate and distribution of aflatoxin during wet-milling process fractions and investigate the aflatoxin destruction during starch conversion to glucose syrup. The present results showed that about half of the aflatoxin content (48.1%) in the infected corn grain was found to be lost in steep liquor, depending upon the aflatoxin type, arranged in the order G1 > G2 > B1 > B2. After wet-milling aflatoxins were distributed into starch, gluten, fiber, and germ. Gluten, fiber, and germ were the most highly contaminated fractions. The loss of aflatoxin during process of starches reached 54.4% in steep water and water process. Although the gluten fraction represents only 9.6% of corn, the higher percentage (25.3%) of aflatoxin was found in this fraction, the fiber and germ account for nearly 29% of the milled corn and contain 11.6% of the aflatoxin. On the other hand, 8.7% of the total aflatoxins in start corn was found in starch fraction which accounts 61% of the milled corn. Aflatoxins G1 and G2 were found lost in higher concentrations compared to the aflatoxin B1 and B2. A higher percentage of AfG1 (86.35%) and AfG2 (78.36%) and a lower percentage of AfB1 (16.3%) and AfB2 (14.7%) were found in starch fraction. The conversion percent of contaminated starch was 89.5% compared with control starch. It can be concluded that aflatoxins were destroyed during starch conversion. Consequently, glucose syrup produced from contaminated starch was found aflatoxin-free.

  11. Effects of Zinc Chelators on Aflatoxin Production in Aspergillus parasiticus

    PubMed Central

    Wee, Josephine; Day, Devin M.; Linz, John E.

    2016-01-01

    Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N′,N′-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin. PMID:27271668

  12. Prenatal exposure to aflatoxin B1: developmental, behavioral, and reproductive alterations in male rats

    NASA Astrophysics Data System (ADS)

    Supriya, Ch.; Reddy, P. Sreenivasula

    2015-06-01

    Previous studies have shown that aflatoxin B1 (AfB1) inhibits androgen biosynthesis as a result of its ability to form a high-affinity complex with the steroidogenic acute regulatory protein. The results of the present study demonstrate the postnatal effects of in utero exposure to AfB1 in the rat. Pregnant Wistar rats were given 10, 20, or 50 μg AfB1/kg body weight daily from gestation day (GD) 12 to GD 19. At parturition, newborns were observed for clinical signs and survival. All animals were born alive and initially appeared to be active. Male pups from control and AfB1-exposed animals were weaned and maintained up to postnatal day (PD) 100. Litter size, birth weight, sex ratio, survival rate, and crown-rump length of the pups were significantly decreased in AfB1-exposed rats when compared to controls. Elapsed time (days) for testes to descend into the scrotal sac was significantly delayed in experimental pups when compared to control pups. Behavioral observations such as cliff avoidance, negative geotaxis, surface rightening activity, ascending wire mesh, open field behavior, and exploratory and locomotory activities were significantly impaired in experimental pups. Body weights and the indices of testis, cauda epididymis, prostate, seminal vesicles, and liver were significantly reduced on PD 100 in male rats exposed to AfB1 during embryonic development when compared with controls. Significant reduction in the testicular daily sperm production, epididymal sperm count, and number of viable, motile, and hypo-osmotic tail coiled sperm was observed in experimental rats. The levels of serum testosterone and activity levels of testicular hydroxysteroid dehydrogenases were significantly decreased in a dose-dependent manner with a significant increase in the serum follicle-stimulating hormone and luteinizing hormone in experimental rats. Deterioration in the testicular and cauda epididymal architecture was observed in experimental rats. The results of fertility

  13. Efficacy of probiotic bacteria in reducing Aspergillus parasiticus aflatoxin production and hepatic cytotoxicity in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus parasiticus produces highly hepatocarcinogenic aflatoxins (AF) in grains, which are used as poultry feed ingredients. Contamination of poultry feed with AF is a major concern to the poultry industry due to serious economic losses stemming from poor performance and diminished egg hatchabi...

  14. The major volatile compound 2-phenylethanol from the biocontrol yeast, Pichia anomala, inhibits growth and expression of aflatoxin biosynthetic genes of Aspergillus flavus.

    PubMed

    Hua, Sui Sheng T; Beck, John J; Sarreal, Siov Bouy L; Gee, Wai

    2014-05-01

    Aspergillus flavus is a ubiquitous saprophyte that is able to produce the most potent natural carcinogenic compound known as aflatoxin B1 (AFB1). This toxin frequently contaminates crops including corn, cotton, peanuts, and tree nuts causing substantial economic loss worldwide. Consequently, more than 100 countries have strict regulations limiting AFB1 in foodstuffs and feedstuffs. Plants and microbes are able to produce volatile compounds that act as a defense mechanism against other organisms. Pichia anomala strain WRL-076 is a biocontrol yeast currently being tested to reduce AF contamination of tree nuts in California. We used the SPME-GC/MS analysis and identified the major volatile compound produced by this strain to be 2-phenylethanol (2-PE). It inhibited spore germination and AF production of A. flavus. Inhibition of AF formation by 2-PE was correlated with significant down regulation of clustering AF biosynthesis genes as evidenced by several to greater than 10,000-fold decrease in gene expression. In a time-course analysis we found that 2-PE also altered the expression patterns of chromatin modifying genes, MYST1, MYST2, MYST3, gcn5, hdaA and rpdA. The biocontrol capacity of P. anomala can be attributed to the production of 2-PE, which affects spore germination, growth, toxin production, and gene expression in A. flavus.

  15. Aflatoxin variability in pistachios.

    PubMed Central

    Mahoney, N E; Rodriguez, S B

    1996-01-01

    Pistachio fruit components, including hulls (mesocarps and epicarps), seed coats (testas), and kernels (seeds), all contribute to variable aflatoxin content in pistachios. Fresh pistachio kernels were individually inoculated with Aspergillus flavus and incubated 7 or 10 days. Hulled, shelled kernels were either left intact or wounded prior to inoculation. Wounded kernels, with or without the seed coat, were readily colonized by A. flavus and after 10 days of incubation contained 37 times more aflatoxin than similarly treated unwounded kernels. The aflatoxin levels in the individual wounded pistachios were highly variable. Neither fungal colonization nor aflatoxin was detected in intact kernels without seed coats. Intact kernels with seed coats had limited fungal colonization and low aflatoxin concentrations compared with their wounded counterparts. Despite substantial fungal colonization of wounded hulls, aflatoxin was not detected in hulls. Aflatoxin levels were significantly lower in wounded kernels with hulls than in kernels of hulled pistachios. Both the seed coat and a water-soluble extract of hulls suppressed aflatoxin production by A. flavus. PMID:8919781

  16. Effects of Aflatoxin on Seeding Growth and Ultrastructure in Plants

    PubMed Central

    Crisan, Eli V.

    1973-01-01

    Nineteen plants belonging to 11 species of the cruciferae were studied to determine the effects of aflatoxin B1 on seed germination and seedling development. Germination was not inhibited in any test organism at a concentration of 100 μg of aflatoxin per ml of agar substrate. Inhibition of elongation of the hypocotyls and roots in the species studied varied from 29 to 93% and from 22 to 91% in the respective tissues. Lepidium sativum was the most susceptible plant studied and exhibited the maximal inhibitory response noted above at concentrations of 8 μg of aflatoxin per ml. The ultrastructure of Lepidium root cells treated with crystalline aflatoxin B1 exhibited morphological changes characteristic of those found in aflatoxin-treated animal cells. In addition to changes in the cytoplasmic organelles, numerous ring-shaped nucleoli with prominent nucleolar caps were produced. The effect of aflatoxin on plant cells is compared with similar effects induced by actinomycin D. Seed germination and seedling development is discussed in relation to the effects of both compounds on deoxyribonucleic acid-dependent ribonucleic acid biosynthesis. Images PMID:4767301

  17. Upstream regulation of mycotoxin biosynthesis.

    PubMed

    Alkhayyat, Fahad; Yu, Jae-Hyuk

    2014-01-01

    Mycotoxins are natural contaminants of food and feed products, posing a substantial health risk to humans and animals throughout the world. A plethora of filamentous fungi has been identified as mycotoxin producers and most of these fungal species belong to the genera Aspergillus, Fusarium, and Penicillium. A number of studies have been conducted to better understand the molecular mechanisms of biosynthesis of key mycotoxins and the regulatory cascades controlling toxigenesis. In many cases, the mycotoxin biosynthetic genes are clustered and regulated by one or more pathway-specific transcription factor(s). In addition, as biosynthesis of many secondary metabolites is coordinated with fungal growth and development, there are a number of upstream regulators affecting biosynthesis of mycotoxins in fungi. This review presents a concise summary of the regulation of mycotoxin biosynthesis, focusing on the roles of the upstream regulatory elements governing biosynthesis of aflatoxin and sterigmatocystin in Aspergillus.

  18. Evaluation of the atoxigenic Aspergillus flavus strain AF36 in pistachio orchards

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The atoxigenic strain Aspergillus flavus AF36, which has been extensively used as a biocontrol agent in commercial corn and cotton fields to reduce aflatoxin contamination, was applied in research pistachio orchards from 2002 to 2005 and in commercial pistachio orchards from 2008 to 2011. AF36 was a...

  19. Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin

    SciTech Connect

    Harvey, R.B.; Clark, D.E.; Huff, W.E.; Kubena, L.F.; Corrier, D.E.; Phillips, I.D.

    1988-04-01

    Flavus-parasiticus species of the genus Aspergillus are recognized as the primary producers of aflatoxins B/sub 1/, B/sup 2/, G/sup 1/, and G/sup 2/, hereafter referred to as aflatoxin (AF). The effects of feeding AF-contaminated diets to growing and finishing pigs have been described with changes in clinical performance, serum biochemistry, histology, and hematology attributed to aflatoxicosis. However, most of these studies evaluated AF-induced changes for a single AF dosage at a given point in time. The present study was designed to characterize how various AF dosages influence bone marrow histology, hematology, prothrombin and activated thromboplastin times, serum amino acids, and serum iron binding capacity during aflatoxicosis in growing pigs.

  20. Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin

    SciTech Connect

    Harvey, R.B.; Clark, D.E.; Huff, W.E.; Kubena, L.F.; Corrier, D.E. ); Phillips, T.D. )

    1988-05-01

    Flavus-parasiticus species of the genus Aspergillus are recognized as the primary producers of aflatoxins B{sub 1}, B{sub 2}, G{sub 1}, and G{sub 2}, hereafter referred to as aflatoxin (AF). The effects of feeding AF-contaminated diets to growing and finishing pigs have been described with changes in clinical performance, serum biochemistry, histology, and hematology attributed to aflatoxicosis. However, most of these studies evaluated AF-induced changes for a single AF dosage at a given point in time. The present study was designed to characterize how various AF dosages influence bone marrow histology, hematology, prothrombin and activated thromboplastin times, serum amino acids, and serum iron binding capacity during aflatoxicosis in growing pigs.

  1. Aflatoxins in hazelnuts and dried figs: Occurrence and exposure assessment.

    PubMed

    Kabak, Bulent

    2016-11-15

    A total of 300 samples of hazelnuts and dried fig were analysed for the incidence of any aflatoxins (AFs). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used to quantify the amounts of AFs. The limit of quantification varied from 0.21 to 0.30μgkg(-1). No AFs were detected in shells of the hazelnuts, while six raw hazelnut kernel samples (12%) and five roasted hazelnut kernel samples (8.3%) contained AFs ranging from 0.09 to 11.3μgkg(-1) and from 0.17 to 11.2μgkg(-1), respectively. Sixteen dried fig samples (12.3%) contained AFs ranging from 0.1 to 28.2μgkg(-1) and a mean value of 3.8μgkg(-1). Three hazelnuts and six dried fig samples exceeded the European maximum limits (MLs) of 5 and 2μgkg(-1) for aflatoxin B1 (AFB1), respectively. The contribution of hazelnuts to AFs exposure is higher than that of dried figs.

  2. Aflatoxins: A Global Concern for Food Safety, Human Health and Their Management

    PubMed Central

    Kumar, Pradeep; Mahato, Dipendra K.; Kamle, Madhu; Mohanta, Tapan K.; Kang, Sang G.

    2017-01-01

    The aflatoxin producing fungi, Aspergillus spp., are widely spread in nature and have severely contaminated food supplies of humans and animals, resulting in health hazards and even death. Therefore, there is great demand for aflatoxins research to develop suitable methods for their quantification, precise detection and control to ensure the safety of consumers’ health. Here, the chemistry and biosynthesis process of the mycotoxins is discussed in brief along with their occurrence, and the health hazards to humans and livestock. This review focuses on resources, production, detection and control measures of aflatoxins to ensure food and feed safety. The review is informative for health-conscious consumers and research experts in the fields. Furthermore, providing knowledge on aflatoxins toxicity will help in ensure food safety and meet the future demands of the increasing population by decreasing the incidence of outbreaks due to aflatoxins. PMID:28144235

  3. The master transcription factor mtfA governs aflatoxin production, morphological development, and pathogenicity in the fungus Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus produces a variety of toxic secondary metabolites, among them the aflatoxins (AFs) are the most well-known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing economically important crops contaminating them with AFs. Molecu...

  4. Influences of Climate on Aflatoxin Producing Fungi and Aflatoxin Contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are potent mycotoxins that cause developmental and immune system suppression, cancer, and death. As a result of regulations intended to reduce human exposure, crop contamination with aflatoxins causes significant economic loss for producers, marketers, and processors of diverse susceptibl...

  5. Ageratum conyzoides essential oil as aflatoxin suppressor of Aspergillus flavus.

    PubMed

    Nogueira, Juliana H C; Gonçalez, Edlayne; Galleti, Silvia R; Facanali, Roseane; Marques, Márcia O M; Felício, Joana D

    2010-01-31

    Aflatoxin B(1) (AFB(1)) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oil of Ageratum conyzoides, on the mycelial growth and aflatoxin B(1) production by Aspergillus flavus were studied. Cultures were incubated in yeast extract-sucrose (YES) broth for days at 25 degrees C at the following different concentrations of the essential oil (from 0.0 to 30mug/mL). The essential oil inhibited fungal growth to different extents depending on the concentration, and completely inhibited aflatoxin production at concentrations above 0.10microg/mL. The analysis of the oil by GC/MS showed that its main components are precocene II (46.35%), precocene I (42.78%), cumarine (5.01%) and Trans-caryophyllene (3.02%). Comparison by transmission electron microscopy of the fungal cells, control and those incubated with different concentrations of essential oil, showed ultra-structural changes which were concentration dependent of the essential oil of A. conyzoides. Such ultra-structural changes were more evident in the endomembrane system, affecting mainly the mitochondria. Degradation was also observed in both surrounding fibrils. The ability to inhibit aflatoxin production as a new biological activity of A.conyzoides L. indicates that it may be considered as a useful tool for a better understanding of the complex pathway of aflatoxin biosynthesis.

  6. Aflatoxins and safe storage

    PubMed Central

    Villers, Philippe

    2014-01-01

    The paper examines both field experience and research on the prevention of the exponential growth of aflatoxins during multi-month post-harvest storage in hot, humid countries. The approach described is the application of modern safe storage methods using flexible, Ultra Hermetic™ structures that create an unbreatheable atmosphere through insect and microorganism respiration alone, without use of chemicals, fumigants, or pumps. Laboratory and field data are cited and specific examples are given describing the uses of Ultra Hermetic storage to prevent the growth of aflatoxins with their significant public health consequences. Also discussed is the presently limited quantitative information on the relative occurrence of excessive levels of aflatoxin (>20 ppb) before vs. after multi-month storage of such crops as maize, rice, and peanuts when under high humidity, high temperature conditions and, consequently, the need for further research to determine the frequency at which excessive aflatoxin levels are reached in the field vs. after months of post-harvest storage. The significant work being done to reduce aflatoxin levels in the field is mentioned, as well as its probable implications on post-harvest storage. Also described is why, with some crops such as peanuts, using Ultra Hermetic storage may require injection of carbon dioxide, or use of an oxygen absorber as an accelerant. The case of peanuts is discussed and experimental data is described. PMID:24782846

  7. Aflatoxins and safe storage.

    PubMed

    Villers, Philippe

    2014-01-01

    The paper examines both field experience and research on the prevention of the exponential growth of aflatoxins during multi-month post-harvest storage in hot, humid countries. The approach described is the application of modern safe storage methods using flexible, Ultra Hermetic™ structures that create an unbreatheable atmosphere through insect and microorganism respiration alone, without use of chemicals, fumigants, or pumps. Laboratory and field data are cited and specific examples are given describing the uses of Ultra Hermetic storage to prevent the growth of aflatoxins with their significant public health consequences. Also discussed is the presently limited quantitative information on the relative occurrence of excessive levels of aflatoxin (>20 ppb) before vs. after multi-month storage of such crops as maize, rice, and peanuts when under high humidity, high temperature conditions and, consequently, the need for further research to determine the frequency at which excessive aflatoxin levels are reached in the field vs. after months of post-harvest storage. The significant work being done to reduce aflatoxin levels in the field is mentioned, as well as its probable implications on post-harvest storage. Also described is why, with some crops such as peanuts, using Ultra Hermetic storage may require injection of carbon dioxide, or use of an oxygen absorber as an accelerant. The case of peanuts is discussed and experimental data is described.

  8. Isolation of methyl syringate as a specific aflatoxin production inhibitor from the essential oil of Betula alba and aflatoxin production inhibitory activities of its related compounds.

    PubMed

    Jermnak, Usuma; Yoshinari, Tomoya; Sugiyama, Yasumasa; Tsuyuki, Rie; Nagasawa, Hiromichi; Sakuda, Shohei

    2012-02-15

    Methyl syringate was isolated from the essential oil of Betula alba as an aflatoxin production inhibitor. It inhibited aflatoxin production of Aspergillus parasiticus and Aspergillus flavus with IC(50) values of 0.9 and 0.8 mM, respectively, without significantly inhibiting fungal growth. Methyl syringate reduced mRNA levels of genes (aflR, pksA, and omtB) [corrected] encoding proteins required for aflatoxin biosynthesis. Methyl gallate, methyl 3,4,5-trimethoxybenzoate, and methyl 3-O-methylgallate inhibited both aflatoxin production and fungal growth of A. parasiticus and A. flavus. However, their acids and syringic acid did not inhibit aflatoxin production and growth of A. parasiticus significantly, although gallic acid inhibited aflatoxin production of A. flavus with selectivity. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of methyl syringate was much weaker than that of gallic acid. These results showed that methyl syringate has a unique inhibitory activity toward aflatoxin production with a different mode of action from that of gallic acid.

  9. Determination of Aflatoxins in Peanut Products in the Northeast Region of São Paulo, Brazil

    PubMed Central

    Oliveira, Carlos A. F.; Gonçalves, Natália B.; Rosim, Roice E.; Fernandes, Andrezza M.

    2009-01-01

    The aim of the present study was to determine aflatoxin levels in peanut products traded in the Northeast region of São Paulo, Brazil. To this end, 240 samples of peanut products traded in the cities of Araras, Leme, Pirassununga and Porto Ferreira were collected from June 2006 to May 2007. The samples were analyzed for aflatoxins (AF) B1, B2, G1 and G2 by high performance liquid chromatography. Results showed 44.2% samples positive for AF at levels of 0.5 to 103.8 μg·kg−1. Nine of the positive samples (3.7% of the analysed samples) had total aflatoxin concentrations (B1+B2+G1+G2) higher than the limit established by Brazilian regulations (20 μg·kg−1). Based on the above data, the probable mean daily intake (PDIM) of aflatoxins from peanut products in the Northeast region of São Paulo was estimated to be 0.23 ng kg b.w. day−1. Although this PDIM value was relatively low, results indicate that aflatoxin contamination of peanut products may be a public health concern in Brazil, when considering the potential exposure of highly susceptible consumers. For example, it should be emphasized that children are potentially exposed to aflatoxins, since they consume large quantities of peanut candies, and these products had the highest number of samples positive for AFB1. PMID:19333440

  10. Production of Aflatoxin on Rice

    PubMed Central

    Shotwell, Odette L.; Hesseltine, C. W.; Stubblefield, R. D.; Sorenson, W. G.

    1966-01-01

    A method has been developed for the production of aflatoxin by growing Aspergillus flavus strain NRRL 2999 on the solid substrate rice. Optimal yields, more than 1 mg of aflatoxin B1 per g of starting material, were obtained in 5 days at 28 C. A crude product containing aflatoxins was isolated by chloroform extraction and precipitation with hexane from concentrated solutions. The crude product consisted of 50% aflatoxin in the following ratio: B1-B2-G1-G2, 100:0.15:0.22:0.02. Aflatoxin B1 was separated from almost all the impurities and from the other aflatoxins by chromatography on silica gel with 1% ethyl alcohol in chloroform. Analytically pure aflatoxin B1 was recrystallized from chloroform-hexane mixtures. Images Fig. 1 PMID:5970829

  11. Aflatoxin decomposition in various soils

    SciTech Connect

    Angle, J.S.

    1986-08-01

    The persistence of aflatoxin in the soil environment could potentially result in a number of adverse environmental consequences. To determine the persistence of aflatoxin in soil, /sup 14/C-labeled aflatoxin B1, was added to silt loam, sandy loam, and silty clay loam soils and the subsequent release of /sup 14/CO/sub 2/ was determined. After 120 days of incubation, 8.1% of the original aflatoxin added to the silt loam soil was released as CO/sub 2/. Aflatoxin decomposition in the sandy loam soil proceeded more quickly than the other two soils for the first 20 days of incubation. After this time, the decomposition rate declined and by the end of the study, 4.9% of the aflatoxin was released as CO/sub 2/. Aflatoxin decomposition proceeded most slowly in the silty clay loam soil. Only 1.4% of aflatoxin added to the soil was released as CO/sub 2/ after 120 days incubation. To determine whether aflatoxin was bound to the silty clay loam soil, aflatoxin B1 was added to this soil and incubated for 20 days. The soil was periodically extracted and the aflatoxin species present were determined using thin layer chromatographic (TLC) procedures. After one day of incubation, the degradation products, aflatoxins B2 and G2, were observed. It was also found that much of the aflatoxin extracted from the soil was not mobile with the TLC solvent system used. This indicated that a conjugate may have formed and thus may be responsible for the lack of aflatoxin decomposition.

  12. Aflatoxins of type B and G affect porcine dendritic cell maturation in vitro.

    PubMed

    Mehrzad, Jalil; Devriendt, Bert; Baert, Kim; Cox, Eric

    2015-01-01

    The toxic effects of highly carcinogenic mycotoxins, especially aflatoxins (AF), on key antigen-presenting cells, such as dendritic cells (DC), are largely unknown. To elucidate the effect of AF on DC function, porcine monocyte-derived DC (MoDC) were treated with a mixture of several AF (i.e., AFB1, AFB2, AFG1, and AFG2) and the phagocytic capacity, the membrane expression level of several DC activation markers, the T-cell proliferation-inducing capacity, and the cytokine secretion pattern were assessed. As compared to untreated MoDC, AF significantly up-regulated the expression of the co-stimulatory molecules CD25 and CD80/86. However, the phagocytic activity of MoDC was not affected by AF treatment. While the cytokine secretion pattern of AF-treated MoDC was similar to control MoDC, the T-cell proliferation-inducing capacity of MoDC was increased upon aflatoxin treatment. The results indicate that a mixture of naturally occurring AF enhances the antigen-presenting capacity of DC, which could explain the observed immunotoxicity of AF by breaking down tolerance and further emphasizes the need to reduce the admissible level of AF in agricultural commodities.

  13. Fluorometric assay for aflatoxins

    SciTech Connect

    Chakrabarti, A.G.

    1984-11-01

    The method that is now widely adopted by the government laboratories for the assay of individual aflatoxin components (B/sub 1/, B/sub 2/, G/sub 1/, and G/sub 2/) utilizes a TLC technique. The extraction and clean-up steps of this technique were further researched but the method is still time consuming. It is, therefore, very important to develop a rapid and accurate assay technique for aflatoxins. The current research proposes a technique which utilizes a Turner Fluorometer.

  14. Aflatoxin levels in chronic hepatitis B patients with cirrhosis or hepatocellular carcinoma in Balıkesir, Turkey.

    PubMed

    Aydın, M; Aydın, S; Bacanlı, M; Başaran, N

    2015-11-01

    Aflatoxins, the secondary metabolites produced by species of naturally occurring Aspergilli, are commonly found in food such as cereals, dried fruits and juice, wine, beer and spices. They are hepatotoxic and are well known human carcinogens based on evidence from human studies. Aflatoxins are an environmental risk factor for the development of hepatocellular carcinoma (HCC). Chronic hepatitis B-infected patients are at increased risk of cirrhosis, hepatic failure and liver cancer. This study was designed to determine the serum aflatoxin B1 (AFB1 ), aflatoxin B2 (AFB2 ), aflatoxin G1 (AFG1 ) and aflatoxin G2 (AFG2 ) concentrations using high-pressure liquid chromatography (HPLC) in hepatitis B-infected patients with or without cirrhosis and liver cancer, alongside healthy controls in Balıkesir, Turkey. The mean AFB1 and total AF levels in patients without liver cancer and cirrhosis were significantly higher than healthy controls. The mean AFB1 and total AF levels in patients with chronic hepatitis B and HCC were significantly higher than infected patients with or without cirrhosis. These results suggest that patients with chronic hepatitis B who are exposed to AFs are at increased risk for developing HCC, which might be prevented by reducing consumption of contaminated foods.

  15. [Aflatoxins--health risk factors].

    PubMed

    Miliţă, Nicoleta Manuela; Mihăescu, Gr; Chifiriuc, Carmen

    2010-01-01

    Aflatoxins are secondary metabolites produced by a group of strains, mainly Aspergillus and Penicillium species. These mycotoxins are bifurano-coumarin derivatives group with four major products B1, B2, G1 and G2 according to blue or green fluorescence emitted in ultraviolet light and according to chromatographic separation. After metabolism of aflatoxin B1 and B2 in the mammalian body, result two metabolites M1 and M2 as hydroxylated derivatives of the parent compound. Aflatoxins have high carcinogenic potential, the most powerful carcinogens in different species of animals and humans. International Agency for Research on Cancer has classified aflatoxin B1 in Group I carcinogens. The target organ for aflatoxins is the liver. In chronic poisoning, aflatoxin is a risk to health, for a long term causing cancer (hepatocellular carcinoma), and in acute intoxications aflatoxin is lethal. This work purpose to discuss aflatoxins issue: the synthesis, absorption and elimination of aflatoxins, the toxicity mechanisms, and measures to limit the content of aflatoxins in food

  16. Monoclonal IgA Antibodies for Aflatoxin Immunoassays

    PubMed Central

    Ertekin, Özlem; Pirinçci, Şerife Şeyda; Öztürk, Selma

    2016-01-01

    Antibody based techniques are widely used for the detection of aflatoxins which are potent toxins with a high rate of occurrence in many crops. We developed a murine monoclonal antibody of immunoglobulin A (IgA) isotype with a strong binding affinity to aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), aflatoxin G2 (AFG2) and aflatoxin M1 (AFM1). The antibody was effectively used in immunoaffinity column (IAC) and ELISA kit development. The performance of the IACs was compatible with AOAC performance standards for affinity columns (Test Method: AOAC 991.31). The total binding capacity of the IACs containing our antibody was 111 ng, 70 ng, 114 ng and 73 ng for AFB1, AFB2, and AFG1 andAFG2, respectively. Furthermore, the recovery rates of 5 ng of each AF derivative loaded to the IACs were determined as 104.9%, 82.4%, 85.5% and 70.7% for AFB1, AFB2, AFG1 and AFG2, respectively. As for the ELISA kit developed using non-oriented, purified IgA antibody, we observed a detection range of 2–50 µg/L with 40 min total test time. The monoclonal antibody developed in this research is hitherto the first presentation of quadruple antigen binding IgA monoclonal antibodies in mycotoxin analysis and also the first study of their utilization in ELISA and IACs. IgA antibodies are valuable alternatives for immunoassay development, in terms of both sensitivity and ease of preparation, since they do not require any orientation effort. PMID:27187470

  17. Characterization of small RNA populations in non-transgenic and aflatoxin-reducing-transformed peanut.

    PubMed

    Power, Imana L; Dang, Phat M; Sobolev, Victor S; Orner, Valerie A; Powell, Joseph L; Lamb, Marshall C; Arias, Renee S

    2017-04-01

    Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls. The objective was to determine the putative involvement of the small RNA populations in aflatoxin reduction. In total, 41 known microRNA (miRNA) families and many novel miRNAs were identified. Among those, 89 known and 10 novel miRNAs were differentially expressed in the transformed lines. We furthermore found two small interfering RNAs derived from the inverted repeat, and 39 sRNAs that mapped without mismatches to the genome of A. flavus and were present only in the transformed lines. This information will increase our understanding of the effectiveness of RNAi and enable the possible improvement of the RNAi technology for the control of aflatoxins.

  18. Aflatoxin B₁ and aflatoxins in ground red chilli pepper after drying.

    PubMed

    Özkan, Ali; Bindak, Recep; Erkmen, Osman

    2015-01-01

    In this study, 180 red chilli pepper (RCP) berry samples were obtained from two different croplands of Gaziantep and Kahramanmaraş (Turkey) in August, September and October. RCP berry samples were dried under sunlight and grinded. Ground red chilli pepper (GRCP) samples were analysed for aflatoxins (AFs, sum of B1, B2, G1 and G2) and AFB1 contamination. According to the results, in 49 of 180 samples, AFB1 and in 37 samples, AFs were higher than legal limits. The lowest amounts of AFs and AFB1 were obtained in August and the highest amounts in October. χ(2) analysis showed that there were no significant differences (p > 0.05) between cities among 3 months according to number of samples with AFs and AFB1 above legal limits. According to the Duncan multiple-range test, there was no significant difference between all months. Strict measures are necessary to produce high-quality GRCP. RCP berry must be treated to reduce moulds before production of GRCP.

  19. Natural aflatoxin uptake by sugarcane (Saccharum officinaurum L.) and its persistence in jaggery.

    PubMed

    Hariprasad, P; Vipin, A V; Karuna, S; Raksha, R K; Venkateswaran, G

    2015-04-01

    The present study focused on aflatoxin (AF) uptake by sugarcanes from contaminated soils, and its persistence in jaggery. Analysis of 25 agricultural soil samples from sugarcane growing fields revealed that 80% were found contaminated with AF ranging from 0.5 to 22 ppb and all samples harbored aflatoxigenic fungi. Forty percent of the juices extracted from sugarcane grown in contaminated soil recorded AF ranging from 1.0 to 9.5 ppb. Conversely, jaggery prepared from those samples was almost free from AF. Further, greenhouse experiment confirms the AF uptake ability of sugarcane plants. Analysis of sugarcane juice and jaggery collected from local vendor showed 21% (0.5 to 6.5 ppb) and 5.6% (0.5-1.0 ppb) of AF contamination, respectively. Aflatoxigenic Aspergillus flavus strain was evaluated for their ability to grow and produce AF on jaggery medium. At 14th day after inoculation, decreased concentration of AF was recorded in jaggery medium ranging from 0 to 120 mg jaggery/ml, above which AF was absent though the fungal growth was noted. From the results, it could be concluded that sugarcane plants have the ability to uptake AF from contaminated soil, but AF was reduced during jaggery preparation. Also, higher concentration of jaggery was inhibitory to AF production.

  20. Determination of aflatoxins in nuts of Tabriz confectionaries by ELISA and HPLC methods

    PubMed Central

    siahi Shadbad, mohammad reza; Ansarin, masoud; Tahavori, Ali; Ghaderi, Faranak; Nemati, Mahboob

    2012-01-01

    Purpose: Aflatoxins (AFs) are a group of mycotoxins and secondary metabolites of various species of Aspergillus. There are various forms of aflatoxins including B1, B2, G1, G2, M1 and M2 types. Aflatoxins cause important health problems and have high potential effect on liver cancer. Therefore, numerous investigations have been conducted during last three decades. The aim of this work is to determine the contamination levels of nuts used by the confectionaries in Tabriz. Method: A total of 142 samples including 35 almond , 26 walnut, 4 seeds of apricot, 6 sunflower seeds kernel, 6 sesame seed, 6 peanuts , 32 pistachio,13 hazelnuts and 14 cashews samples were collected from Tabriz confectionaries. The ELISA method was employed for the screening of total aflatoxins. Result: In 13 cases (28.1% of pistachios, 5.1% of walnuts and 7.1% of cashews) contamination rate of higher than 15 ppb were observed. The HPLC method was applied for the confirmation of ELISA results. Aflatoxin B1 was the highest detected AFs. Conclusion: The overall results of the tested samples indicated that the rate of contamination of pistachios is higher than the other tested samples. PMID:24312781

  1. 7 CFR 983.4 - Aflatoxin.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Aflatoxin. 983.4 Section 983.4 Agriculture Regulations... NEW MEXICO Definitions § 983.4 Aflatoxin. Aflatoxin is one of a group of mycotoxins produced by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring...

  2. 7 CFR 983.4 - Aflatoxin.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Aflatoxin. 983.4 Section 983.4 Agriculture Regulations... NEW MEXICO Definitions § 983.4 Aflatoxin. Aflatoxin is one of a group of mycotoxins produced by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring...

  3. 7 CFR 983.4 - Aflatoxin.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Aflatoxin. 983.4 Section 983.4 Agriculture Regulations... NEW MEXICO Definitions § 983.4 Aflatoxin. Aflatoxin is one of a group of mycotoxins produced by the molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring...

  4. Liver lesions produced by aflatoxins in Rana catesbeiana (bullfrog).

    PubMed

    Grassi, Tony Fernando; Pires, Paulo Wagner; Barbisan, Luis Fernando; Pai-Silva, Maeli Dal; Said, Roueda Abou; de Camargo, João Lauro Viana

    2007-09-01

    This study describes alterations induced in Rana catesbeiana (bullfrog) liver after extended dietary exposure to aflatoxins (AFs). Bullfrogs of both sexes were fed for 120 days a commercial chow blended with a rice bran-based mixture of AFs containing 667.0, 11.65, 141.74, and 3.53 mg/kg of AFs B1, B2, G1, and G2, respectively. Animals were sacrificed on study days 45, 90, and 120. Severe and progressive liver lesions with structural collapse, increased hepatocyte and biliary duct cell proliferation, appearance of basophilic hepatocytes, and diffuse scarring, were observed at all time points. There were no quantitative alterations in the liver melanomacrophage centers of the AFs-exposed animals. Increased amounts of lipid hydroperoxides, indicative of ongoing oxidative stress, were more evident in the Addutor magnum muscle than in the AFs-damaged livers. No tumors were found in the R. catesbeiana livers after 120 days of exposure to relatively high doses of AFs.

  5. [Determination of aflatoxins in cheeses].

    PubMed

    Bartos, J; Matyás, Z

    1979-03-01

    To investigate cheeses for the presence of aflatoxins we chose the very sensitive method of Tuinstra and Bronsgeest (1975) used for the determination of aflatoxin M1 in milk. The method was slightly modified and the presence of aflatoxins was determined in 54 samples of different cheeses. Aflatoxin M1 was found out in 24% of the investigated samples. Most of positive samples were found among the soft cheeses (53.8 3/4), then in processed cheeses (13.6%) and in hard cheeses (12.5%). Aflatoxin M1 was not found in the group of mouldy cheeses and Olomouc cake cheeses, which were investigated in a smaller range. Positive findings did not exceed concentrations of 10 ng per kg, i.e. they did not even reach the value of permissible concentration as proposed in the Czech Socialist Republic for foods (5 microgram per kg).

  6. Natural Products as Tools for Chemogenomic Analysis of Mycotoxin Biosynthesis and Fungal Stress-Response Systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain phenolic compounds with antioxidant properties inhibit aflatoxin biosynthesis in the fungus Aspergillus flavus, without affecting growth. Similarly, some of the same phenolics also inhibit biosynthesis of ochratoxin by A. alliaceous. Exposing A. flavus to oxidative stress, such as hydrogen p...

  7. Aflatoxin-free transgenic maize using host-induced gene silencing

    PubMed Central

    Thakare, Dhiraj; Zhang, Jianwei; Wing, Rod A.; Cotty, Peter J.; Schmidt, Monica A.

    2017-01-01

    Aflatoxins, toxic secondary metabolites produced by some Aspergillus species, are a universal agricultural economic problem and a critical health issue. Despite decades of control efforts, aflatoxin contamination is responsible for a global loss of millions of tons of crops each year. We show that host-induced gene silencing is an effective method for eliminating this toxin in transgenic maize. We transformed maize plants with a kernel-specific RNA interference (RNAi) gene cassette targeting the aflC gene, which encodes an enzyme in the Aspergillus aflatoxin biosynthetic pathway. After pathogen infection, aflatoxin could not be detected in kernels from these RNAi transgenic maize plants, while toxin loads reached thousands of parts per billion in nontransgenic control kernels. A comparison of transcripts in developing aflatoxin-free transgenic kernels with those from nontransgenic kernels showed no significant differences between these two groups. These results demonstrate that small interfering RNA molecules can be used to silence aflatoxin biosynthesis in maize, providing an attractive and precise engineering strategy that could also be extended to other crops to improve food security. PMID:28345051

  8. Effect of climate change on Aspergillus flavus and aflatoxin B1 production.

    PubMed

    Medina, Angel; Rodriguez, Alicia; Magan, Naresh

    2014-01-01

    This review considers the available information on the potential impact of key environmental factors and their interactions on the molecular ecology, growth and aflatoxin production by Aspergillus flavus in vitro and in maize grain. The recent studies which have been carried out to examine the impact of water activity × temperature on aflatoxin biosynthesis and phenotypic aflatoxin production are examined. These have shown that there is a direct relationship between the relative expression of key regulatory and structural genes under different environmental conditions which correlate directly with aflatoxin B1 production. A model has been developed to integrate the relative expression of 10 biosynthetic genes in the pathway, growth and aflatoxin B1 (AFB1) production which was validated under elevated temperature and water stress conditions. The effect of interacting conditions of aw × temperature × elevated CO2 (2 × and 3 × existing levels) are detailed for the first time. This suggests that while such interacting environmental conditions have little effect on growth they do have a significant impact on aflatoxin biosynthetic gene expression (structural aflD and regulatory aflR genes) and can significantly stimulate the production of AFB1. While the individual factors alone have an impact, it is the combined effect of these three abiotic factors which have an impact on mycotoxin production. This approach provides data which is necessary to help predict the real impacts of climate change on mycotoxigenic fungi.

  9. Stability of aflatoxins in solution.

    PubMed

    Diaz, Gonzalo J; Cepeda, Sandra M; Martos, Perry A

    2012-01-01

    The stability of aflatoxins B1, B2, G1, and G2 was studied in solutions containing different concentrations of water, acetonitrile, and/or methanol, and in autosampler vials treated with nitric acid or silanized. When stored at room temperature (20 degrees C) for 24 h, aflatoxins G1 and G2 were stable only in solutions containing 100% organic solvent, whereas aflatoxins B1 and B2 were stable in solutions of methanol-water and acetonitrile-water at greater than 60 and 40% organic content, respectively. At 5 degrees C, aflatoxins G1 and G2 showed a significant decrease in concentration only when kept in less than 20% aqueous organic solvent. Significant loss of aflatoxins was realized in standard, commercially available amber type I borosilicate autosampler vials, but chemical etching of the vials with nitric acid or with silanization prevented aflatoxin degradation. These results indicate that aflatoxins are unstable in aqueous solutions and that this instability can be counteracted by the presence of at least 20% organic solvent and keeping the solutions at 5 degrees C or by the use of treated vials.

  10. Cyclopiazonic Acid Biosynthesis of Aspergillus flavus and Aspergillus oryzae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cyclopiazonic acid (CPA) is an indole-tetramic acid neurotoxin produced by some of the same strains of A. flavus that produce aflatoxins and by some Aspergillus oryzae strains. Despite its discovery 40 years ago, few reviews of its toxicity and biosynthesis have been reported. This review examines w...

  11. Effects of calcium montmorillonite clay and aflatoxin exposure on dry matter intake, milk production, and milk composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fifteen primiparous crossbred dairy cows that were 114 ± 14 d in milk and weighed 533 ± 56 kg were used in a replicated 5×5 Latin square to test the efficacy of NovaSil Plus (NSP) for the reduction of aflatoxin (AF) metabolite (AFM1) in milk and the effect of NSP on milk composition. Cows were hous...

  12. The Impact of Yeast Culture Residue on the Suppression of Dietary Aflatoxin on the Performance of Broiler Breeder Hens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to examine the effect of yeast culture residue (YCR) on the suppression of aflatoxicosis in broiler breeder hens. One hundred twenty, 35-wk-old, Cobb broiler breeder hens of the same cross were fed diets supplemented with aflatoxin (AF) (0 or 3 mg/kg) and YCR (0 or 2 lb/ton) s...

  13. Real-time PCR assays for detection and quantification of aflatoxin-producing molds in foods.

    PubMed

    Rodríguez, Alicia; Rodríguez, Mar; Luque, M Isabel; Martín, Alberto; Córdoba, Juan J

    2012-08-01

    Aflatoxins are among the most toxic mycotoxins. Early detection and quantification of aflatoxin-producing species is crucial to improve food safety. In the present work, two protocols of real-time PCR (qPCR) based on SYBR Green and TaqMan were developed, and their sensitivity and specificity were evaluated. Primers and probes were designed from the o-methyltransferase gene (omt-1) involved in aflatoxin biosynthesis. Fifty-three mold strains representing aflatoxin producers and non-producers of different species, usually reported in food products, were used as references. All strains were tested for aflatoxins production by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The functionality of the proposed qPCR method was demonstrated by the strong linear relationship of the standard curves constructed with the omt-1 gene copy number and Ct values for the different aflatoxin producers tested. The ability of the qPCR protocols to quantify aflatoxin-producing molds was evaluated in different artificially inoculated foods. A good linear correlation was obtained over the range 4 to 1 log cfu/g per reaction for all qPCR assays in the different food matrices (peanuts, spices and dry-fermented sausages). The detection limit in all inoculated foods ranged from 1 to 2 log cfu/g for SYBR Green and TaqMan assays. No significant effect was observed due to the different equipment, operator, and qPCR methodology used in the tests of repeatability and reproducibility for different foods. The proposed methods quantified with high efficiency the fungal load in foods. These qPCR protocols are proposed for use to quantify aflatoxin-producing molds in food products.

  14. Aflatoxins in composite spices collected from local markets of Karachi, Pakistan.

    PubMed

    Asghar, Muhammad Asif; Zahir, Erum; Rantilal, Summan; Ahmed, Aftab; Iqbal, Javed

    2016-06-01

    This survey was carried out to evaluate the occurrence of total aflatoxins (AFs; B1+B2+G1+G2) in unpacked composite spices. A total of 75 samples of composite spices such as biryani, karhai, tikka, nihari and korma masalas were collected from local markets of Karachi, Pakistan, and analysed using HPLC technique. The results indicated that AFs were detected in 77% (n = 58) samples ranging from 0.68 to 25.74 µg kg(-1) with a mean of 4.63 ± 0.95 µg kg(-1). In 88% (n = 66) samples, AFs level was below the maximum limits (ML = 10 µg kg(-1)) as imposed by EU. Furthermore, 61% (n = 46) tested samples contained AFs level between 1 and 10 µg kg(-1), 9% (n = 7) exhibited AFs contamination ranged 10-20 µg kg(-1) and only 3% (n = 2) of the investigated samples contained AFs levels higher than the ML of 20 µg kg(-1) for total aflatoxins as set by the USA. It was concluded that there is need to establish a strict and continuous national monitoring plan to improve safety and quality of spices in Pakistan.

  15. Influences of climate on aflatoxin producing fungi and aflatoxin contamination.

    PubMed

    Cotty, Peter J; Jaime-Garcia, Ramon

    2007-10-20

    Aflatoxins are potent mycotoxins that cause developmental and immune system suppression, cancer, and death. As a result of regulations intended to reduce human exposure, crop contamination with aflatoxins causes significant economic loss for producers, marketers, and processors of diverse susceptible crops. Aflatoxin contamination occurs when specific fungi in the genus Aspergillus infect crops. Many industries frequently affected by aflatoxin contamination know from experience and anecdote that fluctuations in climate impact the extent of contamination. Climate influences contamination, in part, by direct effects on the causative fungi. As climate shifts, so do the complex communities of aflatoxin-producing fungi. This includes changes in the quantity of aflatoxin-producers in the environment and alterations to fungal community structure. Fluctuations in climate also influence predisposition of hosts to contamination by altering crop development and by affecting insects that create wounds on which aflatoxin-producers proliferate. Aflatoxin contamination is prevalent both in warm humid climates and in irrigated hot deserts. In temperate regions, contamination may be severe during drought. The contamination process is frequently broken down into two phases with the first phase occurring on the developing crop and the second phase affecting the crop after maturation. Rain and temperature influence the phases differently with dry, hot conditions favoring the first and warm, wet conditions favoring the second. Contamination varies with climate both temporally and spatially. Geostatistics and multiple regression analyses have shed light on influences of weather on contamination. Geostatistical analyses have been used to identify recurrent contamination patterns and to match these with environmental variables. In the process environmental conditions with the greatest impact on contamination are identified. Likewise, multiple regression analyses allow ranking of

  16. Development of Methods for Determination of Aflatoxins.

    PubMed

    Xie, Lijuan; Chen, Min; Ying, Yibin

    2016-12-09

    Aflatoxins can cause damage to the health of humans and animals. Several institutions around the world have established regulations to limit the levels of aflatoxins in food, and numerous analytical methods have been extensively developed for aflatoxin determination. This review covers the currently used analytical methods for the determination of aflatoxins in different food matrices, which includes sampling and sample preparation, sample pretreatment methods including extraction methods and purification methods of aflatoxin extracts, separation and determination methods. Validation for analysis of aflatoxins and safety considerations and precautions when doing the experiments are also discussed.

  17. Effect of γ irradiation on fungal load and aflatoxins reduction in red chillies

    NASA Astrophysics Data System (ADS)

    Iqbal, Shahzad Zafar; Bhatti, Ijaz Ahmad; Asi, Muhammad Rafique; Zuber, Mohammad; Shahid, Muhammad; Parveen, Ishrat

    2013-01-01

    Chillies are a very important cash crop of Pakistan. The effects of gamma irradiation on microbial load, aflatoxin B1 (AFB1) and total aflatoxins have been studied in chillies samples, collected from different districts of Punjab, Pakistan. Aflatoxins were analyzed using HPLC equipped with a fluorescence detector. The results revealed that among the Aspergillus species isolated, those belonging to section parasiticus were predominant. Gamma radiations of doses 2, 4 and 6 kGy were employed on fungi and chilli samples. The results have demonstrated that the dose of 6 kGy reduced the fungal load by 5 logs. Furthermore, 6 kGy reduced the level of AFB1 and total AFs in ground and whole chillies by 1-2 logs (α < 0.05).

  18. Aflatoxin contamination in food and body fluids in relation to malnutrition and cancer status in Cameroon.

    PubMed

    Tchana, Angele N; Moundipa, Paul F; Tchouanguep, Félicité M

    2010-01-01

    Aflatoxins are food contaminants usually associated with hepatitis, immunodepression, impairment of fertility and cancer. The present work was to determine the presence of aflatoxins in eggs, milk, urine, and blood samples that were collected from various sources and periods; and hepatitis B virus antigen in blood samples. Aflatoxin was found in eggs (45.2%), cow raw milk (15.9%), breast milk (4.8%), urine from kwashiorkor and marasmic kwashiorkor children (45.5%), and sera from primary liver cancer patients (63.9%); HbsAg was also detected in 69.4% of the serum samples, but there was no association between both factors. Both AF and hepatitis B virus seem to be risk factors that could increase the incidence and prevalence rates of malnutrition and cancer in Cameroon.

  19. Evaluation of aluminosilicate compounds to reduce aflatoxin residues and toxicity to poultry and livestock: a review report.

    PubMed

    Harvey, R B; Kubena, L F; Phillips, T D

    1993-01-01

    The aflatoxins (AFs) are reported to be hepatotoxic, mutagenic, immunosuppressive, and carcinogenic. Methods to prevent, reduce, or remediate AF toxicity and residues in the environment are in great demand. Various AF-detoxification procedures are reviewed with particular emphasis on ammoniation and the use of adsorbent compounds to bind AF. A series of in vivo experiments by the authors are reviewed that evaluated the ability of a specific hydrated sodium calcium aluminosilicate (HSCAS) adsorbent to reduce the toxicity of AF to poultry and livestock and to reduce AF residues in milk. These studies showed that HSCAS forms stable bonds with AF in vitro, and when added to AF-contaminated poultry and livestock feeds, HSCAS is able to protect chickens, swine, and lambs from the deleterious toxic effects of AF and to reduce AF residues in milk of dairy cows and goats. These results indicate that HSCAS, when used in conjunction with other mycotoxin management practices, may prove effective for the preventive management of AF-contaminated feedstuffs in livestock and poultry and may reduce AF residues in the food-chain.

  20. Exposure measurement of aflatoxins and aflatoxin metabolites in human body fluids. A short review.

    PubMed

    Leong, Yin-Hui; Latiff, Aishah A; Ahmad, Nurul Izzah; Rosma, Ahmad

    2012-05-01

    Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.

  1. Modelling Aspergillus flavus growth and aflatoxins production in pistachio nuts.

    PubMed

    Marín, Sonia; Ramos, Antonio J; Sanchis, V

    2012-12-01

    Aflatoxins (AFs) are the main contaminants in pistachio nuts. AFs production in pistachio has been attributed to Aspergillus flavus. The aim of this study was to apply existing models to predict growth and AFs production by an A. flavus isolated from pistachios as a function of moisture content and storage temperature of pistachios in order to test their usefulness and complementarities. A full factorial design was used: the moisture content levels assayed were 10, 15, 20, 25 and 30% and incubation temperatures were 10, 15, 20, 25, 30, 37 and 42 °C. Both kinetic and probability models were built to predict growth of the strain under the assayed conditions. Among the assayed models, cardinal ones gave a good quality fit for radial growth rate data. Moreover, the progressive approach, which was developed based on a reduced number of experimental points led to an improved prediction in the validation step. This is quite significant as may allow for improved experimental designs, less costly than full factorial ones. Probability model proved to be concordant in 91% of the calibration set observations. Even though the validation set included conditions around the growth/no-growth interface, there was a 100% agreement in the predictions from the data set (n = 16, cut off = 0.5) after 60 days. Similarly, the probability for AF presence was rightly predicted in 89% of the cases. According to our results EC maximum aflatoxin levels would be surpassed in a period as short as 1 month if pistachio nuts reach 20 °C, unless %mc is ≤10%.

  2. Cytotoxicity of aflatoxin on red blood corpuscles

    SciTech Connect

    Verma, R.J.; Raval, P.J. )

    1991-09-01

    The exact mechanism of aflatoxin action is not clearly understood. In the present investigation the authors report morphological aberrations and increased rate of hemolysis caused by aflatoxins in vitro.

  3. Aflatoxin in Tunisian aleppo pine nuts.

    PubMed

    Boutrif, E; Jemmali, M; Pohland, A E; Campbell, A D

    1977-05-01

    Twenty-six of 50 Aleppo pine nuts samples collected throughout Tunisia showed relatively high levels of contamination by aflatoxin. Some samples contained as much as 2000 ppb aflatoxin B1, and very few contained less than 100 ppb. Total aflatoxins as high as 7550 ppb were found. A traditional pudding, widely consumed in Tunisia, which was prepared from contaminated nuts still contained more than 80% of the aflatoxin originally present in the nuts.

  4. Comparison of expression of secondary metabolite biosynthesis cluster genes in Aspergillus flavus, A. parasiticus, and A. oryzae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More than 55 secondary metabolite biosynthesis gene clusters are predicted to be present in the Aspergillus flavus genome. In spite of this the biosynthesis of only a few metabolites, such as the aflatoxin, cyclopiazonic acid and aflatrem, has been correlated with a particular gene cluster. Using RN...

  5. Aflatoxin Toxicity Reduction in Feed by Enhanced Binding to Surface-Modified Clay Additives

    PubMed Central

    Jaynes, William F.; Zartman, Richard E.

    2011-01-01

    Animal feeding studies have demonstrated that clay additives, such as bentonites, can bind aflatoxins in ingested feed and reduce or eliminate the toxicity. Bentonite deposits are found throughout the world and mostly consist of expandable smectite minerals, such as montmorillonite. The surfaces of smectite minerals can be treated with organic compounds to create surface-modified clays that more readily bind some contaminants than the untreated clay. Montmorillonites treated with organic cations, such as hexadecyltrimethylammonium (HDTMA) and phenyltrimethylammonium (PTMA), more effectively remove organic contaminants, such as benzene and toluene, from water than untreated clay. Similarly, montmorillonite treated with PTMA (Kd = 24,100) retained more aflatoxin B1 (AfB1) from aqueous corn flour than untreated montmorillonite (Kd = 944). Feed additives that reduced aflatoxin toxicity in animal feeding studies adsorbed more AfB1 from aqueous corn flour than feed additives that were less effective. The organic cations HDTMA and PTMA are considered toxic and would not be suitable for clay additives used in feed or food, but other non-toxic or nutrient compounds can be used to prepare surface-modified clays. Montmorillonite (SWy) treated with choline (Kd = 13,800) and carnitine (Kd = 3960) adsorbed much more AfB1 from aqueous corn flour than the untreated clay (Kd = 944). A choline-treated clay prepared from a reduced-charge, high-charge montmorillonite (Kd = 20,100) adsorbed more AfB1 than the choline-treated high-charge montmorillonite (Kd = 1340) or the untreated montmorillonite (Kd = 293). Surface-modified clay additives prepared using low-charge smectites and nutrient or non-toxic organic compounds might be used to more effectively bind aflatoxins in contaminated feed or food and prevent toxicity. PMID:22069725

  6. 7 CFR 983.50 - Aflatoxin regulations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Aflatoxin regulations. 983.50 Section 983.50..., ARIZONA, AND NEW MEXICO Regulations § 983.50 Aflatoxin regulations. The committee shall establish, with the approval of the Secretary, such aflatoxin sampling, analysis, and inspection...

  7. 7 CFR 983.150 - Aflatoxin regulations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Aflatoxin regulations. 983.150 Section 983.150..., ARIZONA, AND NEW MEXICO Rules and Regulations § 983.150 Aflatoxin regulations. (a) Maximum level. No handler shall ship for domestic human consumption, pistachios that exceed an aflatoxin level of 15...

  8. 7 CFR 983.50 - Aflatoxin regulations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Aflatoxin regulations. 983.50 Section 983.50..., ARIZONA, AND NEW MEXICO Regulations § 983.50 Aflatoxin regulations. The committee shall establish, with the approval of the Secretary, such aflatoxin sampling, analysis, and inspection...

  9. 7 CFR 983.50 - Aflatoxin regulations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Aflatoxin regulations. 983.50 Section 983.50..., ARIZONA, AND NEW MEXICO Regulations § 983.50 Aflatoxin regulations. The committee shall establish, with the approval of the Secretary, such aflatoxin sampling, analysis, and inspection...

  10. 7 CFR 983.150 - Aflatoxin regulations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Aflatoxin regulations. 983.150 Section 983.150..., ARIZONA, AND NEW MEXICO Rules and Regulations § 983.150 Aflatoxin regulations. (a) Maximum level. No handler shall ship for domestic human consumption, pistachios that exceed an aflatoxin level of 15...

  11. 7 CFR 983.150 - Aflatoxin regulations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Aflatoxin regulations. 983.150 Section 983.150..., ARIZONA, AND NEW MEXICO Rules and Regulations § 983.150 Aflatoxin regulations. (a) Maximum level. No handler shall ship for domestic human consumption, pistachios that exceed an aflatoxin level of 15...

  12. Aspergillus flavus: The Major Producer of Aflatoxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is an opportunistic pathogen of crops. It is important because it produces aflatoxin as a secondary metabolite in the seeds of a number of crops both before and after harvest. Aflatoxin is a potent carcinogen that is highly regulated in most countries. In the field, aflatoxin i...

  13. Diversity of aflatoxin-producing fungi and their impact on food safety in sub-Saharan Africa.

    PubMed

    Probst, C; Bandyopadhyay, R; Cotty, P J

    2014-03-17

    Crops frequently contaminated by aflatoxins are important sources of revenue and daily nourishment in many portions of sub-Saharan Africa. In recent years, reports have associated aflatoxins with diminished human health and export opportunities in many African Nations. Aflatoxins are highly carcinogenic metabolites mainly produced by members of Aspergillus sect. Flavi. The current study examined aflatoxin-producing fungi associated with maize grain intended for human consumption in 18 sub-Saharan African countries. 4469 Aspergillus sect. Flavi isolates were obtained from 339 samples. The majority (75%) of isolates belonged to the L strain morphotype of A. flavus. Minor percentages were A. tamarii (6%), A. parasiticus (1%), and isolates with S strain morphology (3%). No A. bombycis or A. nomius isolates were detected. Phylogenetic analyses of partial sequences of the nitrate reductase gene (niaD, 1.3kb) and the aflatoxin pathway transcription factor gene (aflR, 1.7kb) were used to verify isolate assignments into species and lineages. Phylogenetics resolved S strain isolates producing only B aflatoxins into two lineages fully supported by sizes of deletions in the gene region spanning the aflatoxin biosynthesis genes cypA (aflU) and norB (aflF). One lineage was the A. flavus S strain with either 0.9 or 1.5kb deletions. The second lineage, recently described from Kenya, has a 2.2kb deletion. Taxa with S strain morphology differed in distribution with strain SBG limited to West Africa and both A. minisclerotigenes and the new lineage from Kenya in Central and East Africa. African A. flavus L strain isolates formed a single clade with L strain isolates from other continents. The sampled maize frequently tested positive for aflatoxins (65%), fumonisins (81%), and deoxynivalenol (40%) indicating the presence of fungi capable of producing the respective toxins. Percentage of samples exceeding US limits for total aflatoxins (regulatory limit), fumonisins (advisory limit

  14. Effects on aflatoxin M1 residues in milk by addition of hydrated sodium calcium aluminosilicate to aflatoxin-contaminated diets of dairy cows.

    PubMed

    Harvey, R B; Phillips, T D; Ellis, J A; Kubena, L F; Huff, W E; Petersen, H D

    1991-09-01

    Hydrated sodium calcium aluminosilicate (HSCAS), an anticaking agent for agricultural feeds, was added to aflatoxin (AF)-contaminated diets of 3 lactating dairy cows and evaluated for its potential to reduce aflatoxin M1 (AFM1) residues in milk. During phase I, cows were fed alternating diets that consisted of 200 micrograms of AF/kg of feed for 7 days, 0.5% HSCAS plus 200 micrograms of AF/kg of feed for 7 days, and feed with the HSCAS removed for a final 7 days. The AFM1 milk concentrations from the intervals with HSCAS added to diets were compared with those times when HSCAS was absent. The presence of 0.5% HSCAS in feed containing 200 micrograms of AF/kg reduced AFM1 secretion into the milk by an average of 0.44 micrograms/L (from pretreatment of 1.85 micrograms/L to 1.41 micrograms/L with HSCAS, a 24% reduction). Following a 10-day period of noncontaminated feed consumption and no AFM1 residues in the milk, phase II of the study was begun. The same experimental design as phase I was used, but the dosages of HSCAS and AF were changed to 1.0% and 100 micrograms/kg of feed, respectively. The addition of 1.0% HSCAS in feed containing 100 micrograms of AF/kg decreased AFM1 content in the milk by an average of 0.40 micrograms/L (from a pretreatment of 0.91 micrograms/L to 0.51 micrograms/L when HSCAS was present, a 44% reduction). These findings suggest that HSCAS, a high-affinity sorbent compound for AF in vitro, is capable of reducing the secretion of AFM1 into milk.

  15. Occurrence and exposure assessment of aflatoxins in Catalonia (Spain).

    PubMed

    Cano-Sancho, G; Sanchis, V; Marín, S; Ramos, A J

    2013-01-01

    The main objective of this study was to assess the exposure of Catalonian (Spain) population to AFs. Thus, two sub-objectives were considered: (1) to assess the occurrence of AFs in food marketed in Catalonia, and (2) to assess the consumption of those foods susceptible to AFs contamination by Catalonian population. AFs were analysed in a total of 603 samples considering special commodities as free-gluten, ethnic or baby foods. Analytical method consisted of an extraction and clean-up of aflatoxins step using immunoaffinity columns, and determination by HPLC with post-column photochemical derivatization and fluorescence detection. Food dietary intake was assessed using a food frequency questionnaire, administered to 1387 individuals by trained interviewers. Contamination and consumption raw datasets were combined by means of a direct method and a stochastic method, building the pseudo-parametric bootstrap confidence intervals of the main outputs. Margins of exposure (MoE) and cancer incidence were estimated for the different collectives. The highest percentages of positive samples were found in red pepper, pistachios and peanuts. Considering our results, the most exposed group was the celiac sufferer collective followed by the adolescents; however health concern should not be expected in the population groups.

  16. Dietary exposure to aflatoxin from maize and groundnut in young children from Benin and Togo, West Africa.

    PubMed

    Egal, S; Hounsa, A; Gong, Y Y; Turner, P C; Wild, C P; Hall, A J; Hell, K; Cardwell, K F

    2005-10-15

    Aflatoxins are a family of fungal toxins that are carcinogenic to man and cause immunosuppression, cancer and growth reduction in animals. We conducted a cross-sectional study among 480 children (age 9 months to 5 years) across 4 agro-ecological zones (SS, NGS, SGS and CS) in Benin and Togo to identify the effect of aflatoxin exposure on child growth and assess the pattern of exposure. Prior reports on this study [Gong, Y.Y.,Cardwell, K., Hounsa, A., Egal, S., Turner, Hall, A.J., Wild, C.P., 2002. Dietary aflatoxin exposure and impaired growth in young children from Benin and Togo: cross sectional study. British Medical Journal 325, 20-21, Gong, Y.Y., Egal, S., Hounsa, A., Turner, P.C., Hall, A.J., Cardwell, K., Wild, C.P., 2003. Determinants of aflatoxin exposure in young children from Benin and Togo, West Africa: the critical role of weaning and weaning foods. International Journal of Epidemiology, 32, 556-562] showed that aflatoxin exposure among these children is widespread (99%) and that growth faltering is associated with high blood aflatoxin-albumin adducts (AF-alb adducts), a measure of recent past exposure. The present report demonstrates that consumption of maize is an important source of aflatoxin exposure for the survey population. Higher AF-alb adducts were correlated with higher A. flavus (CFU) infestation of maize (p=0.006), higher aflatoxin contamination (ppb) of maize (p<0.0001) and higher consumption frequencies of maize (p=0.053). The likelihood of aflatoxin exposure from maize was particularly high in agro-ecological zones where the frequency of maize consumption (SGS and CS), the presence of aflatoxin in maize (SGS) or the presence of A. flavus on maize (NGS and SGS) was relatively high. Socio-economic background did not affect the presence of A. flavus and aflatoxin in maize, but better maternal education was associated with lower frequencies of maize consumption among children from the northernmost agro-ecological zone (SS) (p=0.001). The

  17. Two new aflatoxin producing species, and an overview of Aspergillus section Flavi

    PubMed Central

    Varga, J.; Frisvad, J.C.; Samson, R.A.

    2011-01-01

    Aspergillus subgenus Circumdati section Flavi includes species with usually biseriate conidial heads, in shades of yellow-green to brown, and dark sclerotia. Several species assigned to this section are either important mycotoxin producers including aflatoxins, cyclopiazonic acid, ochratoxins and kojic acid, or are used in oriental food fermentation processes and as hosts for heterologous gene expression. A polyphasic approach was applied using morphological characters, extrolite data and partial calmodulin, β-tubulin and ITS sequences to examine the evolutionary relationships within this section. The data indicate that Aspergillus section Flavi involves 22 species, which can be grouped into seven clades. Two new species, A. pseudocaelatus sp. nov. and A. pseudonomius sp. nov. have been discovered, and can be distinguished from other species in this section based on sequence data and extrolite profiles. Aspergillus pseudocaelatus is represented by a single isolate collected from Arachis burkartii leaf in Argentina, is closely related to the non-aflatoxin producing A. caelatus, and produces aflatoxins B & G, cyclopiazonic acid and kojic acid, while A. pseudonomius was isolated from insects and soil in the USA. This species is related to A. nomius, and produces aflatoxin B1 (but not G-type aflatoxins), chrysogine and kojic acid. In order to prove the aflatoxin producing abilities of the isolates, phylogenetic analysis of three genes taking part in aflatoxin biosynthesis, including the transcriptional regulator aflR, norsolonic acid reductase and O-methyltransferase were also carried out. A detailed overview of the species accepted in Aspergillus section Flavi is presented. PMID:21892243

  18. Purification of a vesicle-vacuole fraction functionally linked to aflatoxin synthesis in Aspergillus parasiticus

    PubMed Central

    CHANDA, Anindya; ROZE, Ludmila; PASTOR, Alicia; FRAME, Melinda; LINZ, John E.

    2009-01-01

    Current studies in our laboratory demonstrate a functional link between vesicles, vacuoles and aflatoxin biosynthesis in the filamentous fungus, Aspergillus parasiticus. Under aflatoxin inducing conditions in liquid yeast-extract sucrose medium, A. parasiticus undergoes a shift from vacuole biogenesis to accumulation of an enhanced number of vesicles which exhibit significant heterogeneity in size and density. As a first step in conducting a detailed analysis of the role of these organelles in aflatoxin synthesis, we developed a novel method to purify the vesicle and vacuole fraction using protoplasts prepared from cells harvested during aflatoxin synthesis. The method includes the following steps: 1] preparation of protoplasts from mycelia grown for 36h under aflatoxin inducing conditions; 2] release of vesicles and vacuoles from purified protoplasts in the presence of Triton X-100; and 3] fractionation of the vesicles and vacuoles using a “one-step high density cushion”. The vesicle-vacuole fraction showed a 35 fold enrichment in alpha-mannosidase activity (vacuole marker) and non-detectable succinate dehydrogenase and lactate dehydrogenase activities (mitochondrial and cytoplasmic markers, respectively). Confocal laser scanning microscopy with the vacuole dyes MDY-64 and CMAC demonstrated that the fraction contained pure vesicles and vacuoles and was devoid of membranous debris. Transmission electron microscopy (TEM) confirmed that no mitochondria or unbroken protoplasts contaminated the purified fraction. The purified organelles exhibited significant size heterogeneity with a range of sizes similar to that observed in whole cells and protoplasts. PMID:19358865

  19. Inhibition of aflatoxin formation by some spices.

    PubMed

    Mabrouk, S S; El-Shayeb, N M

    1980-01-01

    The effects of black pepper, cinnamon, peppermint, cumin, ginger and clove on growth and aflatoxin formation of Aspergillus flavus were studied in rice powdercorn steep (RC) medium. The effects of the first five spices were judged to be inhibition of aflatoxin formation rather than of mycelial growth. Clove completely inhibited both mycelial growth and aflatoxin formation at a concentration above 0.1%. No aflatoxin was produced when cumin and mint levels of 5% and 10% were used. Black pepper and ginger levels of 10% decreased aflatoxin formation by 100%. Higher concentrations of cinnamon, mint, cumin and ginger stimulated mycelial growth.

  20. Effects of Aflatoxin on Liver and Protective Effectiveness of Esterified Glucomannan in Merino Rams

    PubMed Central

    Colakoglu, Fatma; Donmez, Hasan Hüseyin

    2012-01-01

    The effects of total aflatoxin (AF) given orally on liver in Merino rams were studied. In addition, this study was conducted in order to evaluate the efficacy of an esterified glucomannan (EG) for protection against aflatoxicosis. One-year-old 32 Merino rams were divided into four equal groups. The control group (C) was fed with the commercial feed. The AF group was fed with commercial feed plus 250 μg/day of total AF. The EG group was fed with commercial feed plus 2 g/day of EG. The AF + EG group was fed with commercial feed plus 250 μg/day of total AF and 2 g/day of EG. After feeding period, tissue samples were taken from the liver in order to perform histological analyses. Vacuolar degeneration with small and large droplets and hydropic degeneration in hepatocytes were observed in the AF group. The ceroid pigmentation was observed in macrophages in groups or one by one. It was observed that the fat rate in hepatocytes was 2.6% in the C group, 35.5% in the AF group, 2.9% in the EG group, and 9.6% in the AF + EG group. In conclusion, the adverse effects caused by aflatoxicosis on the liver could be ameliorated by adding EG to the ration. PMID:23304087

  1. ord1, an oxidoreductase gene responsible for conversion of O-methylsterigmatocystin to aflatoxin in Aspergillus flavus.

    PubMed Central

    Prieto, R; Woloshuk, C P

    1997-01-01

    Among the enzymatic steps in the aflatoxin biosynthetic pathway, the conversion of O-methylsterigmatocystin to aflatoxin has been proposed to be catalyzed by an oxidoreductase. Transformants of Aspergillus flavus 649WAF2 containing a 3.3-kb genomic DNA fragment and the aflatoxin biosynthesis regulatory gene aflR converted exogenously supplied O-methylsterigmatocystin to aflatoxin B1. A gene, ord1, corresponding to a transcript of about 2 kb was identified within the 3.3-kb DNA fragment. The promoter region presented a putative AFLR binding site and a TATA sequence. The nucleotide sequence of the gene revealed an open reading frame encoding a protein of 528 amino acids with a deduced molecular mass of 60.2 kDa. The gene contained six introns and seven exons. Heterologous expression of the ord1 open reading frame under the transcriptional control of the Saccharomyces cerevisiae galactose-inducible gal1 promoter results in the ability to convert O-methylsterigmatocystin to aflatoxin B1. The data indicate that ord1 is sufficient to accomplish the last step of the aflatoxin biosynthetic pathway. A search of various databases for similarity indicated that ord1 encodes a cytochrome P-450-type monooxygenase, and the gene has been assigned to a new P-450 gene family named CYP64. PMID:9143099

  2. Effects of Milk Yield, Feed Composition, and Feed Contamination with Aflatoxin B1 on the Aflatoxin M1 Concentration in Dairy Cows’ Milk Investigated Using Monte Carlo Simulation Modelling

    PubMed Central

    van der Fels-Klerx, H. J.; Camenzuli, Louise

    2016-01-01

    This study investigated the presence of aflatoxin M1 (AfM1) in dairy cows’ milk, given predefined scenarios for milk production, compound feed (CF) contamination with aflatoxin B1 (AfB1), and inclusion rates of ingredients, using Monte Carlo simulation modelling. The model simulated a typical dairy farm in the Netherlands. Six different scenarios were considered, based on two lactation and three CF composition scenarios. AfB1 contamination of the CF was based on results from the Dutch national monitoring programme for AfB1 in feed materials from 2000 until 2010. Monitoring data from feed materials used in CF production for dairy cattle in the Netherlands were used. Additionally, AfB1 contamination data from an incident in maize in 2013 were used. In each scenario, five different transfer equations of AfB1 from feed to AfM1 in the milk were used, and 1000 iterations were run for each scenario. The results showed that under these six scenarios, the weekly farm concentration of AfM1 in milk was above the EC threshold in less than 1% of the iterations, with all five transfer equations considered. However, this increased substantially in weeks when concentrations from the contaminated maize batch were included, and up to 28.5% of the iterations exceeded the EC threshold. It was also observed that an increase in the milk production had a minimal effect on the exceedance of the AfM1 threshold due to an apparent dilution effect. Feeding regimes, including the composition of CF and feeding roughages of dairy cows, should be carefully considered based on the potential AfM1 contamination of the farm’s milk. PMID:27735836

  3. Aflatoxin levels and exposure assessment of Spanish infant cereals.

    PubMed

    Hernández-Martínez, Raquel; Navarro-Blasco, Iñigo

    2010-01-01

    Aflatoxins (AFB1, AFB2, AFG1 and AFG2) are immunosuppressant, mutagenic, teratogenic and carcinogenic agents with a widespread presence in foodstuffs. Since human exposure to aflatoxins occurs primarily by contaminated food intake, and given the greater susceptibility of infants to their adverse effects, the quantification of these mycotoxins in infant food based on cereals is of relevance. Aflatoxin levels were determined in 91 Spanish infant cereals classified in terms of non- and organically produced and several types from 10 different manufacturers, using a extraction procedure followed by inmunoaffinity column clean-up step and HPLC with fluorescence detection (FLD) and post-column derivatisation (Kobra Cell system). Daily aflatoxin intake was also assessed. Preliminary analysis showed a valuable incidence of detected infant cereal samples at an upper concentration level than the detection limit for total aflatoxin (66%), corresponding to a 46, 40, 34 and 11% for AFB1, AFB2, AFG1 and AFG2, respectively. Lower aflatoxin values (median, Q1, Q3) in conventional infant cereal (n = 74, AFB1: AF (AFtotal): 0.01 (aflatoxin levels. Gluten-free and cereals with dehydrated fruits had an intermediate level and milk- or honey-based cereals and multi-cereals contained the lowest levels. With the exception of the non-compliant cocoa-based organic formulation

  4. Evaluation of the efficacy of bentonite from the south of Argentina to ameliorate the toxic effects of aflatoxin in broilers.

    PubMed

    Rosa, C A; Miazzo, R; Magnoli, C; Salvano, M; Chiacchiera, S M; Ferrero, S; Saenz, M; Carvalho, E C; Dalcero, A

    2001-02-01

    In vitro studies indicated that a sodium bentonite (SB) from southern Argentina had a high ability to sorb aflatoxin B1 (AFB1) from aqueous solution. We evaluated this compound for its ability to reduce the effects of total aflatoxins (AF; 5 mg AFB1/kg) in the diet of growing broiler chickens from 30 to 52 d of age. The diets were amended with 0.3% Argentinean SB to determine the effect of this compound during aflatoxicosis. When compared with the controls, BW gains were significantly (P < 0.05) lower for broilers fed diets containing AF alone (1,865 vs. 1,552 g). No differences were found between the BW gains of broiler chickens fed diets without AF (1,785 g) and those of chickens fed AF + SB (1,809 g). These results suggest that effects of AF treatment were ameliorated when SB was used in the broiler chick diets. The AF significantly (P < 0.05) decreased feed efficiency. Liver, kidney, and pancreas relative weights increased in chickens fed the diet containing AF alone. Alterations in the levels of serum total protein, albumin (ALB), and globulins (GLOB) were observed for AF diets, and moderate protection was provided by the sorbent. The ALB:GLOB ratio decreased in both groups of birds fed with the AF-contaminated diet, and we observed a moderate increase in this ratio by 0.3% addition of SB. The histopathological findings in liver sections of broiler fed diets with AF + SB indicated a nonprotective effect of this adsorbent, because a moderate hepatic steatosis was observed.

  5. The major volatile compound 2-phenylethanol from the biocontrol yeast Pichia anomala inhibits growth and expression of aflatoxin biosynthetic genes of Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus is a globally distributed fungus and an important food contaminant because it produces the most potent natural carcinogenic compound known as aflatoxin (AF) B1. The major volatile from a yeast strain, Pichia anomala WRL-076 was identified by SPEM-GC/MS analysis to be 2-phenylethan...

  6. Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

    PubMed Central

    Rodrigues, P.; Venâncio, A.; Lima, N.

    2012-01-01

    Aflatoxin contamination of nuts is an increasing concern to the consumer's health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested for their aflatoxigenic ability. Almond samples were tested for aflatoxin contamination by HPLC-fluorescence. In total, 352 fungi belonging to Aspergillus section Flavi were isolated from Portuguese almonds: 127 were identified as A. flavus (of which 28% produced aflatoxins B), 196 as typical or atypical A. parasiticus (all producing aflatoxins B and G), and 29 as A. tamarii (all nonaflatoxigenic). Aflatoxins were detected in only one sample at 4.97 μg/kg. PMID:22666128

  7. Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7

    PubMed Central

    Xu, Liang; Eisa Ahmed, Mohamed Farah; Sangare, Lancine; Zhao, Yueju; Selvaraj, Jonathan Nimal; Xing, Fuguo; Wang, Yan; Yang, Hongping; Liu, Yang

    2017-01-01

    Food and feed contamination by aflatoxin (AF)B1 has adverse economic and health consequences. AFB1 degradation by microorganisms or microbial enzymes provides a promising preventive measure. To this end, the present study tested 43 bacterial isolates collected from maize, rice, and soil samples for AFB1-reducing activity. The higher activity was detected in isolate L7, which was identified as Bacillus shackletonii. L7 reduced AFB1, AFB2, and AFM1 levels by 92.1%, 84.1%, and 90.4%, respectively, after 72 h at 37 °C. The L7 culture supernatant degraded more AFB1 than viable cells and cell extracts; and the degradation activity was reduced from 77.9% to 15.3% in the presence of proteinase K and sodium dodecyl sulphate. A thermostable enzyme purified from the boiled supernatant was designated as Bacillus aflatoxin-degrading enzyme (BADE). An overall 9.55-fold purification of BADE with a recovery of 39.92% and an activity of 3.85 × 103 U·mg−1 was obtained using chromatography on DEAE-Sepharose. BADE had an estimated molecular mass of 22 kDa and exhibited the highest activity at 70 °C and pH 8.0, which was enhanced by Cu2+ and inhibited by Zn2+, Mn2+, Mg2+, and Li+. BADE is the major protein involved in AFB1 detoxification. This is the first report of a BADE isolated from B. shackletonii, which has potential applications in the detoxification of aflatoxins during food and feed processing. PMID:28098812

  8. 7 CFR 983.4 - Aflatoxin.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring compounds produced by molds, which can be spread in improperly processed and stored nuts, dried fruits and grains....

  9. 7 CFR 983.4 - Aflatoxin.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... molds Aspergillus flavus and Aspergillus parasiticus. Aflatoxins are naturally occurring compounds produced by molds, which can be spread in improperly processed and stored nuts, dried fruits and grains....

  10. Manual sorting to eliminate aflatoxin from peanuts.

    PubMed

    Galvez, F C F; Francisco, M L D L; Villarino, B J; Lustre, A O; Resurreccion, A V A

    2003-10-01

    A manual sorting procedure was developed to eliminate aflatoxin contamination from peanuts. The efficiency of the sorting process in eliminating aflatoxin-contaminated kernels from lots of raw peanuts was verified. The blanching of 20 kg of peanuts at 140 degrees C for 25 min in preheated roasters facilitated the manual sorting of aflatoxin-contaminated kernels after deskinning. The manual sorting of raw materials with initially high aflatoxin contents (300 ppb) resulted in aflatoxin-free peanuts (i.e., peanuts in which no aflatoxin was detected). Verification procedures showed that the sorted sound peanuts contained no aflatoxin or contained low levels (<15 ppb) of aflatoxin. The results obtained confirmed that the sorting process was effective in separating contaminated peanuts whether or nor contamination was extensive. At the commercial level, when roasters were not preheated, the dry blanching of 50 kg of peanuts for 45 to 55 min facilitated the proper deskinning and subsequent manual sorting of aflatoxin-contaminated peanut kernels from sound kernels.

  11. Prevention of maternal and developmental toxicity in rats via dietary inclusion of common aflatoxin sorbents: potential for hidden risks.

    PubMed

    Mayura, K; Abdel-Wahhab, M A; McKenzie, K S; Sarr, A B; Edwards, J F; Naguib, K; Phillips, T D

    1998-02-01

    In earlier work, we have reported that a phyllosilicate clay (HSCAS or NovaSil) can tightly and selectively bind the aflatoxins in vitro and in vivo. Since then, a variety of untested clay and zeolitic minerals have been added to poultry and livestock feeds as potential "aflatoxin binders." However, the efficacy and safety of these products have not been determined. A common zeolite that has been frequently added to animal feed is clinoptilolite. Our objectives in this study were twofold: (1) to utilize the pregnant rat as an in vivo model to compare the potential of HSCAS and clinoptilolite to prevent the developmental toxicity of aflatoxin B1 (AfB1), and (2) to determine the effect of these two sorbents on the metabolism and bioavailability of AfB1. Clay and zeolitic minerals (HSCAS or clinoptilolite) were added to the diet at a level of 0.5% (w/w) and fed to pregnant Sprague-Dawley rats throughout pregnancy (i.e., day 0 to 20). Treatment groups (HSCAS or clinoptilolite) alone and in combination with AfB1 were exposed to sorbents in the feed as well as by gavage. Untreated and AfB1 control animals were fed the basal diet without added sorbent. Between gestation days 6 and 13, animals maintained on diets containing sorbent were gavaged with corn oil in combination with an amount of the respective sorbent equivalent to 0.5% of the estimated maximum daily intake of feed. Animals receiving AfB1 were dosed orally (between days 6 and 13) with AfB1 (2 mg/kg body wt) either alone or concomitantly with a similar quantity of the respective sorbent. Evaluations of toxicity were performed on day 20. These included: maternal (mortality, body weights, feed intake, and litter weights), developmental (embryonic resorptions and fetal body weights), and histological (maternal livers and kidneys). Sorbents alone were not toxic; AfB1 alone and with clinoptilolite resulted in significant maternal and developmental toxicity. Animals treated with HSCAS (plus AfB1) were comparable to

  12. Interaction of Wild Strains of Aspergilla with Aspergillus parasiticus ATCC15517 and Aflatoxin Production †

    PubMed Central

    Martins, H. Marina; Almeida, Inês; Marques, Marta; Bernardo, Fernando

    2008-01-01

    Aflatoxins are secondary metabolites produced by some competent mould strains of Aspergillus flavus, A. parasiticus and A. nomius. These compounds have been extensively studied with regards to their toxicity for animals and humans; they are able to induce liver cancer and may cause a wide range of adverse effects in living organisms. Aflatoxins are found as natural contaminants of food and feed; the main line of the strategy to control them is based on the prevention of the mould growth in raw vegetable or during its storage and monitoring of each crop batch. Mould growth is conditioned by many ecological factors, including biotic ones. Hazard characterization models for aflatoxins in crops must take into consideration biotic interactions between moulds and their potential effects on growth development. The aim of this work is to study the effect of the biotic interaction of 14 different wild strains of Aspergilla (different species), with a competent strain (Aspergillus parasiticus ATCC 15517) using an in vitro production model. The laboratory model used was a natural matrix (humidified cracked corn), on which each wild strain challenged the aflatoxin production of a producer strain. Cultures were incubated at 28°C for 12 days and sampled at the 8th and 12th. Aflatoxin detection and quantification was performed by HPLC using a procedure with a MRPL = 1 μg/kg. Results of those interactive cultures revealed both synergic and antagonistic effects on aflatoxin biosynthesis. Productivity increases were particularly evident on the 8th day of incubation with wild strains of A. flavipes (+ 70.4 %), A. versicolor (+ 54.9 %) and A. flavus 3 (+ 62.6 %). Antagonistic effects were found with A. niger (− 69.5%), A. fumigatus (− 47.6 %) and A. terreus (− 47.6 %) on the 12th day. The increased effects were more evident on the 8th of incubation and the decreases were more patent on the 12th day. Results show that the development of Aspergilla strains concomitantly with

  13. Inhibitory Effects of Silver Nanoparticles on Growth and Aflatoxin B1 Production by Aspergillus Parasiticus

    PubMed Central

    Mousavi, Seyyed Amin Ayatollahi; Pourtalebi, Somayyeh

    2015-01-01

    Background: Aflatoxins (AFs) are secondary hazardous fungal metabolites that are produced by strains of some Aspergillus species on food and feedstuffs. Aflatoxin B1 (AFB1) is one of the most important AF with high toxicity. Prevention of AF production and their elimination from food products is a matter of importance for many researchers in the last decades. Nanomaterials applications in medical science have been widely studied in the recent years. Most of existing researches seek the effect of nanoparticles on bacteria, fungi, and viruses. The aim of this study was to determine the effects of silver nanoparticles (AgNPs) on growth and AFB1 production of AF-producing Aspergillus parasiticus. Methods: A parasiticus was inoculated (106 conidia per ml of medium) to potato dextrose broth (PDB) medium and then AgNPs was added and incubated with shaking at 130 rpm and 28°C for 7 days. AF was assayed by high performance liquid chromatography (HPLC). Microbiological assay (MBA) on microplates contained potato dextrose broth (PDB) medium (4 days at 28°C) at different concentrations of AgNPs (60, 80, 100, 120, 140, 160, 180 and 200 μg/ml) was measured. Results: The results demonstrated that a minimum inhibition concentration (MIC) equal to 180 μg/ml was determined for AgNPs against A. parasiticus. The AgNPs effectively inhibited AFB1 production at a concentration of 90 μg/ml. Conclusion: The results obtained in this study show AgNPs at concentrations lower than the MIC drastically inhibited production of AFB1 by A. parasiticus in culture medium. The AgNPs may be useful to control AF contamination of susceptible crops in the field. PMID:26538778

  14. Auxin Biosynthesis

    PubMed Central

    Zhao, Yunde

    2014-01-01

    lndole-3-acetic acid (IAA), the most important natural auxin in plants, is mainly synthesized from the amino acid tryptophan (Trp). Recent genetic and biochemical studies in Arabidopsis have unambiguously established the first complete Trp-dependent auxin biosynthesis pathway. The first chemical step of auxin biosynthesis is the removal of the amino group from Trp by the TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS (TAA) family of transaminases to generate indole-3-pyruvate (IPA). IPA then undergoes oxidative decarboxylation catalyzed by the YUCCA (YUC) family of flavin monooxygenases to produce IAA. This two-step auxin biosynthesis pathway is highly conserved throughout the plant kingdom and is essential for almost all of the major developmental processes. The successful elucidation of a complete auxin biosynthesis pathway provides the necessary tools for effectively modulating auxin concentrations in plants with temporal and spatial precision. The progress in auxin biosynthesis also lays a foundation for understanding polar auxin transport and for dissecting auxin signaling mechanisms during plant development. PMID:24955076

  15. A novel method for determination of aflatoxin B1 mediated by FCLA + BSA

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da

    2005-02-01

    As a chemiluminescence (CL) probe, 3,7-dihydro-6-{4-{2-(N"-(5-fluoresceinyl) thioureido)ethoxy}phenyl}-2-met -hylimi-dazo{1,2-a}pyrazin-3-one dosium salt (FCLA) can sensitively and specifically react with singlet oxygen (1O2 ) and superoxide(O2""). BSA (Bovine Serum Albumin) can enlarge the CL intensity of FCLA to 860%. This report presents a novel method for determination of Aflatoxin B1 (AfB1) mediated by FCLA+BSA. The concentration of AFB1 showed an obvious positive correlation with the CL intensity mediated by FCLA+BSA. This method could measure accurately ng/ml of AfB1 concentration. At the same time, the fluorescence spectrum of FCLA+BSA and FCLA+BSA+AfB1 were measured respectively, which showed that the fluorescence intensity of FCLA+BSA+AfB1 was higher than FCLA+BSA. Comparing the peak value of FCLA, FCLA+BSA and FCLA+BSA+AfB1 had a 6nm Einstein shift (red shift). The study suggested that CL method mediated by FCLA+BSA might be applicable to the determination of AfB1 concentration.

  16. [Regulation of antibiotic biosynthesis in Streptomycetes].

    PubMed

    Matseliukh, B P

    2006-01-01

    The review of literature presents the modern data about cascade regulation of antibiotic biosynthesis in Streptomycetes including basal and global levels. The first regulatory level is presented by related proteins of SARP family playing the role of positive transcription factors of pathway-specific genes of clusters of antibiotic biosynthesis. In their turn these regulatory genes are under the control of higher regulatory level represented by bldA- and A-factor-dependent cascade regulation and two-component signal transduction system (AfsK-AfsR, AbsAl-AbsA2, AfsQ1-AfsQ2 and others), consisting of sensor protein kinase and response regulator protein.Streptomycetes, in contrast to other microorganisms, have dozens of protein kinases and related regulator proteins that testifies to the great importance of protein phosphorylation in regulation of secondary metabolism and morphogenesis in cell response to internal and external signals. The role of camp, ppGpp and other proteins in regulation of antibiotic biosynthesis was also considered in this review.

  17. Biosynthesis and Toxicological Effects of Patulin

    PubMed Central

    Puel, Olivier; Galtier, Pierre; Oswald, Isabelle P.

    2010-01-01

    Patulin is a toxic chemical contaminant produced by several species of mold, especially within Aspergillus, Penicillium and Byssochlamys. It is the most common mycotoxin found in apples and apple-derived products such as juice, cider, compotes and other food intended for young children. Exposure to this mycotoxin is associated with immunological, neurological and gastrointestinal outcomes. Assessment of the health risks due to patulin consumption by humans has led many countries to regulate the quantity in food. A full understanding of the molecular genetics of patulin biosynthesis is incomplete, unlike other regulated mycotoxins (aflatoxins, trichothecenes and fumonisins), although the chemical structures of patulin precursors are now known. The biosynthetic pathway consists of approximately 10 steps, as suggested by biochemical studies. Recently, a cluster of 15 genes involved in patulin biosynthesis was reported, containing characterized enzymes, a regulation factor and transporter genes. This review includes information on the current understanding of the mechanisms of patulin toxinogenesis and summarizes its toxicological effects. PMID:22069602

  18. Separation of aflatoxins from filter cake

    SciTech Connect

    Ogawa, I.; Chriswell, C.D.

    1982-02-01

    Size-exclusion chromatography using silianized porous silica microspheres is used to clean up an environmental sample prior to aflatoxin analysis. B/sub 1/ and B/sub 2/ aflatoxins were found in an anaerobic digestor filter cake sample at concentrations of 1 ppb.

  19. Aflatoxins, hepatocellular carcinoma and public health.

    PubMed

    Magnussen, Arvin; Parsi, Mansour A

    2013-03-14

    Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide, primarily affecting populations in the developing countries. Aflatoxin, a food contaminant produced by the fungi Aspergillus flavus and Aspergillus parasiticus, is a known human carcinogen that has been shown to be a causative agent in the pathogenesis of HCC. Aflatoxin can affect a wide range of food commodities including corns, oilseeds, spices, and tree nuts as well as milk, meat, and dried fruit. Many factors affect the growth of Aspergillus fungi and the level of aflatoxin contamination in food. Drought stress is one of the factors that increase susceptibility of plants to Aspergillus and thus aflatoxin contamination. A recent drought is thought to be responsible for finding of trace amounts of aflatoxin in some of the corn harvested in the United States. Although it's too soon to know whether aflatoxin will be a significant problem, since United States is the world's largest corn producer and exporter, this has raised alarm bells. Strict regulations and testing of finished foods and feeds in the United States should prevent a major health scare, and prevent human exposure to deleterious levels of aflatoxin. Unfortunately, such regulations and testing are not in place in many countries. The purpose of this editorial is to summarize the current knowledge on association of aflatoxin and HCC, encourage future research and draw attention to this global public health issue.

  20. Aflatoxins in Iran: Nature, Hazards and Carcinogenicity

    PubMed Central

    Khoshpey, B; Farhud, DD; Zaini, F

    2011-01-01

    Many studies have shown that mycotoxin contamination of agricultural products is a challenge for individual’s health especially in developing countries. Improper production and storage of foods, prepare conditions for aflatoxin production in crops, especially rice, wheat, pistachio, walnut, almond, etc which are the main sources of foods for people. Feeding livestock by contaminated bread is another way of human exposure to mycotoxins, especially aflatoxin and because of expensive methods for detecting and analyzing aflatoxin in laboratory; it is not measured in foods. This manuscript is a review of some Iranian and nonIranian reports about aflatoxin, its exposure ways, its adverse effect on human health and nutrition, as well as methods for reducing its exposure. Based on studies on foods, aflatoxin exposure is high in Iran. Since livestock feeding by contaminated bread is one of the potential ways for milk contamination, we should control and reduce aflatoxin contamination by improving production process, storage condition and livestock feeding as soon as possible. Pistachio is one of the most important exporting products of Iran and to maintain Iran’s position in exporting of this product, specific regulations on lowering its contamination with aflatoxin should be considered seriously. Finally, effective controlling of all food and feedstuffs which are vulnerable to aflatoxin contamination is necessary to prevent its effects. PMID:23113099

  1. Clinical implications of food contaminated by aflatoxins.

    PubMed

    Hendrickse, R G

    1991-01-01

    Aflatoxins have been incriminated, mainly on circumstantial evidence, in hepatocellular carcinoma, acute hepatic failure and Reye's syndrome, but other possible effects of continuous or intermittent dietary exposure to aflatoxins, which occurs widely in the tropics, have received little study. Over the past 10 years evidence has steadily accumulated that incriminates aflatoxins in the aetiology of kwashiorkor, a widespread and serious disorder of children in the tropics, previously believed to be caused by protein deficiency. Investigation of human breast milk, undertaken initially to elucidate the pathogenesis of kwashiorkor in breastfed infants, has revealed widespread and serious exposure to aflatoxins from this source. Extension of these studies to pregnant women, in turn, revealed widespread and serious prenatal aflatoxin exposure. In laboratory and farm animals, such exposure has serious implications for immune and hepatic functions, and is detrimental to growth and development. Recent analysis of heroin samples show that heroin addicts may also be exposed to these toxins. These findings show that human exposure to aflatoxins may begin prenatally, persist during breastfeeding, and continue into adult life. It is postulated that aflatoxins (i) play a role in the aetiology of kwashiorkor, (ii) increase neonatal susceptibility to infection and jaundice, (iii) increase childhood susceptibility to infections and malignant disease, (iv) compromise immune responses to prophylactic immunisations and (v) may play a role in the pathogenesis of diseases in heroin addicts. There are indications also that acute, fatal aflatoxin poisoning which masquerades as 'hepatitis' may occur more frequently than is currently appreciated.

  2. Beyond aflatoxin: four distinct expression patterns and functional roles associated with Aspergillus flavus secondary metabolism gene clusters

    PubMed Central

    Georgianna, D. Ryan; Fedorova, Natalie D.; Burroughs, James L.; Dolezal, Andrea L.; Bok, J.; Horowitz-Brown, S.; Woloshuk, Charles P.; Yu, Jiujiang; Keller, Nancy P.; Payne, Gary A.

    2014-01-01

    SUMMARY Species of Aspergillus produce a diverse array of secondary metabolites, and recent genomic analysis predicts that these species have the capacity to synthesize many more compounds. It has been possible to infer the presence of 55 gene clusters associated with secondary metabolism in A. flavus, however, only three metabolic pathways - aflatoxin, cyclopiazonic acid (CPA), and aflatrem - have been assigned to these clusters. To gain insight into the regulation of, and infer ecological significance for the 55 secondary metabolite gene clusters predicted in A. flavus, we examined their expression over 28 diverse conditions. Variables included culture media and temperature, fungal development, colonization of developing maize seeds, and misexpression of laeA, a global regulator of secondary metabolism. Hierarchical clustering analysis of expression profiles allowed us to categorize the gene clusters into four distinct clades. Gene clusters for the production of aflatoxins, CPA, and seven other unknown compound(s) were identified as belonging to one clade. To further explore the relationships found by gene expression analysis, aflatoxin and CPA production were quantified under five different cell culture environments known to be conducive or non-conducive for aflatoxin biosynthesis and during colonization of developing maize seeds. Results from these studies showed that secondary metabolism gene clusters have distinctive gene expression profiles. Aflatoxin and CPA were found to have unique regulation but are similar enough that they would be expected to co-occur in substrates colonized with A. flavus. PMID:20447271

  3. Laboratory evaluation of chemical control of aflatoxin production in unshelled peanuts (Arachis hypogaea L.).

    PubMed

    Calori-Domingues, M A; Fonseca, H

    1995-01-01

    Propionic acid (ammonium salt) at 3000 mg/kg (PA1) and 5000 mg/kg (PA2) of unshelled peanuts (UP); grapefruit seed extract at 5000 mg/kg (GF1) and 10,000 mg/kg (GF2); sodium orthophenylphenate at 2500 mg/kg (SOP1) and 5000 mg/kg (SOP2); thiabendazole 1000 mg/kg (TBZ1) and 5000 mg/kg (TBZ2) were studied in the laboratory, to verify their efficiency in controlling fungal growth and aflatoxin (AF) production on moist UP (16-18% moisture content). Moist UP were put into polyethylene bags with cotton plugs and incubated at 30 +/- 2 degrees C for 28 days. Treatments were considered efficient when the AF content (B1 + G1) remained under 30 micrograms/kg. PA1 treatment was efficient till 14 days of incubation and PA2 during the whole incubation period (28 days). All other treatments were not efficient, showing AF contents from 150 to 108,333 micrograms/kg during the incubation periods. Propionic acid, used as ammonium propionate, at 5000 mg/kg shows promise in controlling aflatoxin production when applied to moist unshelled peanuts.

  4. Aflatoxin-albumin adduct formation after single and multiple doses of aflatoxin B(1) in rats treated with Thai medicinal plants.

    PubMed

    Vinitketkumnuen, U; Chewonarin, T; Dhumtanom, P; Lertprasertsuk, N; Wild, C P

    1999-07-16

    The objective was to conduct an assessment of the ability of two Thai medicinal plants, Cymbopogon citratus Stapf and Murdannia loriformis, to modulate levels of serum aflatoxin-albumin (AF-albumin) adducts following aflatoxin B(1) (AFB(1)) exposure in rats. The influence of the plant extracts on AF-albumin adduct formation after a single exposure to 250 microg/kg body weight (bw) AFB(1) was measured over a 48-h period. Rats received M. loriformis extract (3 g/kg bw) or C. citratus Stapf extract (5 g/kg bw) daily for the week prior to the AFB(1) administration. In control rats, maximum adduct levels were observed 12 h post-AFB(1) treatment but in the animals receiving Murdannia extract, maximum levels occurred earlier, at 4 h post-treatment. No such effect was observed with the Cymbopogon extract. Daily treatment of rats with AFB(1) at 250 microg/kg bw for 3 weeks caused serum AF-albumin adduct levels to accumulate over a 10-14 day period and reach plateau levels 4.4-fold higher than observed after a single dose. Treatment with Murdannia extract for 1 week before and then throughout the AFB(1) exposure period resulted in a slight decrease in the AF-albumin adduct levels in the first week of the intervention. After that time, however, the reduction in adduct levels in the Murdannia extract group did not differ significantly from controls. No significant alteration in the biomarker levels was seen with the Cymbopogon extract treatments compared to control rats.

  5. Natural occurrence of aflatoxins and ochratoxin A in processed spices marketed in Malaysia.

    PubMed

    Ali, Norhayati; Hashim, Noor Hasani; Shuib, Nor Shifa

    2015-01-01

    The analysis of aflatoxins (B1, B2, G1 and G2) and ochratoxin A (OTA) was performed in processed spices marketed in Penang, Malaysia, using immunoaffinity columns and HPLC equipped with fluorescence detector (HPLC-FD). The processed powdered spices analysed include dried chilli, fennel, cumin, turmeric, black and white pepper, poppy seed, coriander, 'garam masala', and mixed spices for fish, meat and chicken curry. Two different studies were carried out. The limit of detection (LOD) was 0.01 ng g(-1) for each aflatoxin (AF) and 0.10 ng g(-1) for OTA (signal-to-noise ratio = 3:1). In the first study, 34 commercial processed spices analysed with a mean level, range and incidence of positive samples for total AF were 1.61 ng g(-1), 0.01-9.34 ng g(-1) and 85%, respectively, and for AFB1 were 1.38 ng g(-1), 0.01-7.68 ng g(-1) and 85%, respectively. The mean level, range and incidence of positive samples for OTA were 2.21 ng g(-1), 0.14-20.40 ng g(-1) and 79%, respectively. Natural co-occurrence of AF and OTA was found in 25 (74%) samples. In the second study of 24 commercial processed spices, the mean level, range and incidence of positive samples for total AF were 8.38 ng g(-1), 0.32-31.17 ng g(-1) and 88%, respectively, and for AFB1 were 7.31 ng g(-1), 0.32-28.43 ng g(-1) and 83%, respectively. Fifteen positive samples for total AF and two positive samples for OTA exceeded the permissible Malaysian limit of 5 ng g(-1). Contamination of both mycotoxins in spices may represent another route of exposure to consumers due to their frequent and prolonged consumption, as spices are common ingredients in popular dishes among Asian countries.

  6. Dietary exposure to aflatoxin and fumonisin among Tanzanian children as determined using biomarkers of exposure

    PubMed Central

    Shirima, Candida P.; Kimanya, Martin E.; Kinabo, Joyce L.; Routledge, Michael N.; Srey, Chou; Wild, Christopher P.; Gong, Yun Yun

    2014-01-01

    Scope The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure. Methods and results A total of 148 children aged 12 to 22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p<0.01) with higher levels being associated with higher maize intake (p<0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7–65.0), 19.9 (13.5–29.2) and 3.6 (2.8–4.7) pg/mg albumin in children from Kigwa, Nyabula and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p<0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1–493.0), 211.7 (161.1–278.1) and 82.8 (58.3–117.7) pg/ml in Kigwa, Nyabula and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins. Conclusion Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied. PMID:23776058

  7. RNA Sequencing of Contaminated Seeds Reveals the State of the Seed Permissive for Pre-Harvest Aflatoxin Contamination and Points to a Potential Susceptibility Factor

    PubMed Central

    Clevenger, Josh; Marasigan, Kathleen; Liakos, Vasileios; Sobolev, Victor; Vellidis, George; Holbrook, Corley; Ozias-Akins, Peggy

    2016-01-01

    Pre-harvest aflatoxin contamination (PAC) is a major problem facing peanut production worldwide. Produced by the ubiquitous soil fungus, Aspergillus flavus, aflatoxin is the most naturally occurring known carcinogen. The interaction between fungus and host resulting in PAC is complex, and breeding for PAC resistance has been slow. It has been shown that aflatoxin production can be induced by applying drought stress as peanut seeds mature. We have implemented an automated rainout shelter that controls temperature and moisture in the root and peg zone to induce aflatoxin production. Using polymerase chain reaction (PCR) and high performance liquid chromatography (HPLC), seeds meeting the following conditions were selected: infected with Aspergillus flavus and contaminated with aflatoxin; and not contaminated with aflatoxin. RNA sequencing analysis revealed groups of genes that describe the transcriptional state of contaminated vs. uncontaminated seed. These data suggest that fatty acid biosynthesis and abscisic acid (ABA) signaling are altered in contaminated seeds and point to a potential susceptibility factor, ABR1, as a repressor of ABA signaling that may play a role in permitting PAC. PMID:27827875

  8. Aflatoxins, hydroxylated metabolites, and aflatoxicol from breast muscle of laying hens.

    PubMed

    Díaz-Zaragoza, M; Carvajal-Moreno, M; Méndez-Ramírez, I; Chilpa-Galván, N C; Avila-González, E; Flores-Ortiz, C M

    2014-12-01

    Aflatoxins (AF) are toxic fungal secondary metabolites that are pathological to animals and humans. This study identified and quantified AF (AFB(1), AFB(2), AFG(1), AFG(2)) and their hydroxylated metabolites (AFM(1), AFM(2), AFP(1)) and aflatoxicol (AFL) from laying hen breast muscles. Aflatoxins pass from cereal feed to the laying hen tissues, causing economic losses, and from there to humans. To detect the passage of AF from feed to hen breast muscle tissues, an experiment that included 25 Hy-Line W36 121-wk-old hens was performed for 8 d. Hens in individual cages were distributed into 3 groups: a control group, with feed free of AFB(1), and 2 experimental groups, with feed spiked with 2 AFB(1) dosages: 30 µg·kg(-1) (low) or 500 µg·kg(-1) (high). The daily feed consumption per hen was recorded and afterward hens were euthanized and breast muscles were collected, weighed, and dried individually. Aflatoxins were extracted by 2 chemical methods and quantified by HPLC. Both methods were validated by lineality (calibration curves), recovery percentage (>80%), limit of detection, and limit of quantification. The AF (µg·kg(-1)) averages recovered in control breast muscles were as follows: AFB(1) (18); AFG(1), AFM(2), and AFL (0); AFG(2) (1.3); AFM(1) (52), and AFP1 (79). Hens fed with feed spiked with 30 µg·kg(-1) of AFB(1) had AFG(1) (16); AFG(2) (72); AFM(1) (0); AFM(2) (18); AFP(1) (145); and AFL (5 µg·kg(-1)). Hens with feed spiked with 500 µg·kg(-1) of AFB(1) had AFG(1) (512); AFG(2) (7); AFM(1) (4,775); AFM(2) (0); AFP(1) (661); and AFL (21 µg·kg(-1)). The best AF extraction method was Qian and Yang's method, modified by adding additional AF from both Supelclean LC18 SPE columns; its limit of detection (0.5 ng·mL(-1)) was lower compared with that of Koeltzow and Tanner, which was 1 ng·mL(-1).

  9. Effects of clay after an aflatoxin challenge on aflatoxin clearance, milk production, and metabolism of Holstein cows.

    PubMed

    Sulzberger, S A; Melnichenko, S; Cardoso, F C

    2017-03-01

    Oral supplementation of clay to dairy cattle has been reported to reduce toxicity of aflatoxin (AF) in contaminated feed. The objective of this study was to determine the effects of 3 concentrations of dietary clay supplementation in response to an AF challenge. Ten multiparous rumen-cannulated Holstein cows [body weight (mean ± SD) = 669 ± 20 kg and 146 ± 69 d in milk], were assigned to 1 of 5 treatments in a randomized replicated 5 × 5 Latin square design balanced to measure carryover effects. Periods (21 d) were divided in an adaptation phase (d 1 to 14) and a measurement phase (d 15 to 21). From d 15 to 17, cows received an AF challenge. The challenge consisted of 100 μg of aflatoxin B1 (AFB1)/kg of dietary dry matter intake (DMI). The material was fitted into 10-mL gelatin capsules and administered into the rumen through a rumen-cannula based on the average DMI obtained on d 12 to 14. Treatments were no clay plus an AF challenge (POS); 3 different concentrations of clay (0.5, 1, or 2% of dietary DMI) plus an AF challenge; and a control consisting of no clay and no AF challenge (C). Statistical analysis was performed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Two contrasts, CONT1 (POS vs. C) and CONT2 (POS vs. the average of 0.5, 1, and 2% clay), were compared along with the linear and quadratic treatment effects (POS, 0.5%, 1%, 2%). Cows supplemented with clay had lower AF excretion in milk as aflatoxin M1 (AFM1; 0.5% = 20.83 μg/d, 1% = 22.82 μg/d, and 2% = 16.51 μg/d) and AF transfer from rumen fluid to milk (AFM1; 0.5% = 1.01%, 1% = 0.98%, and 2% = 0.74%) compared with cows in POS (AFM1 = 27.81 μg/d and AF transfer = 1.37%, CONT2). Similarly, concentrations of AFM1 in milk (0.5% = 0.35 μg/kg, 1% = 0.30 μg/kg, 2% = 0.25 μg/kg), AFB1 in feces (0.5% = 1.79 μg/g, 1% = 1.52 μg/kg, 2% = 1.48 μg/kg), and AFB1 in rumen fluid (0.5% = 0.05 μg/kg, 1% = 0.02 μg/kg, 2% = 0.02 μg/kg) were reduced in cows fed clay compared with POS

  10. Dietary supplementation with whey protein and ginseng extract counteracts oxidative stress and DNA damage in rats fed an aflatoxin-contaminated diet.

    PubMed

    Abdel-Aziem, Sekena H; Hassan, Aziza M; Abdel-Wahhab, Mosaad A

    2011-07-14

    Aflatoxins (AF) are among the most potent naturally occurring carcinogens and aflatoxin-B1 (AFB(1)) is classified as a group-1 carcinogen. Since the ingestion of aflatoxins-contaminated food is associated with several liver diseases, the aim of the present study was to evaluate whether AF-induced damage in rats can be counteracted by feeding with whey-protein concentrates (WPC) and Korean ginseng extract (KGE). Eighty male Sprague-Dawley rats were divided into eight equal groups and treated daily for 30 days as follows: a control group (fed an AF-free diet), a group fed ad libitum an AF-contaminated diet (2.5mg/kg diet), a group treated orally with WPC (0.5ml/rat/day), a group treated orally with KGE (20mg/kg body weight), a group treated orally with WPC+KGE, and three groups that were fed the AF-contaminated diet and were treated orally with WPC, KGE or WPC+KGE, respectively. Throughout the experimental period, animals received WPC or KGE during the consumption of their respective diet. Bone-marrow micronucleus formation, DNA fragmentation, fatty-acid synthesis (FAS) and phospholipid-hydroperoxide-glutathione-peroxidase (PHGPx) mRNA expression, and oxidative stress were assayed in liver and testis. The results indicated that ingestion of aflatoxin resulted in a significant increase in micronucleated normochromatic erythrocytes (Mn-NCE) in bone marrow, DNA fragmentation, FAS mRNA expression and lipid peroxidation in both organs, and a significant decrease in micronucleated polychromatic erythrocytes/micronucleated normochromatic erythrocytes (PCE/NCE) ratio in bone marrow, PHGPx gene expression and GSH in liver and testis. Treatments with WPC and/or KGE had a significant effect on Mn-NCE or the PCE/NCE ratio in bone marrow. However, KGE or KGE+WPC increased PHGPx gene expression and GSH in testis accompanied with a significant decrease in lipid peroxidation in liver and testis and FAS-mRNA expression in liver. WPC, KGE or WPC+KGE treatments combined with exposure

  11. Determination of aflatoxins in botanical roots by a modification of AOAC Official Method 991.31: single-laboratory validation.

    PubMed

    Weaver, Carol M; Trucksess, Mary W

    2010-01-01

    AOAC Official Method 991.31 for the determination of aflatoxins (AFs; sum of aflatoxins B1, B2, G1, and G2) in corn, raw peanuts, and peanut butter by using immunoaffinity column cleanup with LC has been modified and applied to the determination of AFs in botanical roots. The modifications were necessary to improve the performance of the method for matrixes beyond corn and peanuts. The extraction solvent was changed from a mixture of methanol and water to acetonitrile and water. The accuracy, repeatability, and reproducibility characteristics of this method were determined. Replicates of 10 test portions of each powdered root (black cohosh, echinacea, ginger, ginseng, kava kava, and valerian) at each spiking level (AFs at 0, 2, 4, 8, and 16 ng/g) were analyzed on 3 separate days. Test portions were extracted with acetonitrile-water (84 + 16, v/v), and the extracts were centrifuged, diluted with phosphate-buffered saline, filtered, and applied to an immunoaffinity column containing antibodies specific for AFs. After the column was washed with water, the toxins were eluted from the column with methanol and quantified by HPLC with fluorescence detection. All test materials except kava kava were found to contain AF at < 0.1 ng/g. Kava kava was naturally contaminated with AFs at 0.5 ng/g. Average within-day and between-days recoveries of AFs from botanical roots ranged from 88 to 112 and from 86 to 118%, respectively. Total RSD values for within-day and between-days repeatability ranged from 1.4 to 15.9%. HorRat values were < 0.4 for all of the matrixes examined. The modified AOAC Official Method 991.31 was found to be applicable to an analysis of the six botanical roots.

  12. Chemiluminescence and fluorescence spectrum methods for determination of Aflatoxin B1 mediated by FCLA + BSA

    NASA Astrophysics Data System (ADS)

    Chen, WenLi; Xing, Da

    2005-04-01

    BSA (Bovine Serum Albumin) can enlarge the CL intensity of FCLA(3,7-dihydro-6-{4-{2-(N'-(5-fluoresceinyl) thioureido)ethoxy}phenyl}-2-methylimi-dazo{1,2-a}pyrazin-3-one dosium salt) to 763%. This report presents novel methods for determination of Aflatoxin B1 (AfB1) mediated by FCLA+BSA. The concentration of AFB1 showed an obvious positive correlation with the chemiluminescence (CL) intensity mediated by FCLA+BSA, correlative coefficient R@0.94. This method could measure accurately ng/ml of AfB1 concentration. 365nm as excitated wavelength, 440nm and 520nm-two fluorescence peaks of FCLA+BSA+AfB1 were found. The fluorescence intensity of peak at 440nm showed an obvious positive correlation with the concentration of AFB1, R@0.97; the fluorescence intensity of peak at 520nm showed a positive correlation with the concentration of AFB1, R@0.90. Comparing the peak of FCLA, FCLA+BSA and FCLA+BSA+AfB1 had a 6nm Einstein shift (red shift). The study suggested that CL and fluorescence spectrum methods mediated by FCLA+BSA might be applicable to the determination of AfB1 concentration.

  13. Risks of ingestion of aflatoxin-contaminated groundnuts in Benin: scale measurements, beliefs, and socioeconomic factors.

    PubMed

    Jolly, C M; Bayard, B; Vodouhe, S

    2009-10-01

    This study evaluates farmers' beliefs and perceived risks of aflatoxin (AF) on the consumption, production, and marketing of groundnuts. A survey was conducted with 181 farmers in Benin to assess their beliefs of AF effects on the marketing of groundnuts, and finally human and animal health. Awareness and action factors were also evaluated. Relationships of the belief and action factors with socioeconomic variables were evaluated using multiple indicators and multiple causes (MIMIC) models within a socioeconomic framework using a health belief model (HBM). The results indicate that the scale of the various constructs is reliable and the validity conforms to expectations. The unifactorial models developed in this study provide a satisfactory fit with NFl, CFI, and GFI exceeding 0.90. The results reveal that gender, age, and years of experience in farming significantly impact farmers' action regarding the reduction of AF in groundnut production and marketing. Male farmers are more likely to be aware of AF problems in groundnuts and feel more susceptible to the problems than their female counterparts. Gender and education seem to be dominating factors in the perception of barriers to mitigating the effects of AF, and male and older farmers are more likely to perceive the benefits of producing and marketing good quality groundnuts.

  14. Addition of Carbon to the Culture Medium Improves the Detection Efficiency of Aflatoxin Synthetic Fungi

    PubMed Central

    Suzuki, Tadahiro; Iwahashi, Yumiko

    2016-01-01

    Aflatoxin (AF) is a harmful secondary metabolite that is synthesized by the Aspergillus species. Although AF detection techniques have been developed, techniques for detection of AF synthetic fungi are still required. Techniques such as plate culture methods are continually being modified for this purpose. However, plate culture methods require refinement because they suffer from several issues. In this study, activated charcoal powder (carbon) was added to a culture medium containing cyclodextrin (CD) to enhance the contrast of fluorescence and improve the detection efficiency for AF synthetic fungi. Two culture media, potato dextrose agar and yeast extract sucrose agar, were investigated using both plate and liquid cultures. The final concentrations of CD and carbon in the media were 3 mg/mL and 0.3 mg/mL, respectively. Addition of carbon improved the visibility of fluorescence by attenuating approximately 30% of light scattering. Several fungi that could not be detected with only CD in the medium were detected with carbon addition. The carbon also facilitated fungal growth in the potato dextrose liquid medium. The results suggest that addition of carbon to media can enhance the observation of AF-derived fluorescence. PMID:27854283

  15. Influence of the antimicrobial compound allyl isothiocyanate against the Aspergillus parasiticus growth and its aflatoxins production in pizza crust.

    PubMed

    Quiles, Juan M; Manyes, Lara; Luciano, Fernando; Mañes, Jordi; Meca, Giuseppe

    2015-09-01

    Aflatoxins (AFs) are secondary metabolites produced by different species of Aspergillus, such as Aspergillus flavus and Aspergillus parasiticus, which possess mutagenic, teratogenic and carcinogenic activities in humans. In this study, active packaging devices containing allyl isothiocyanate (AITC) or oriental mustard flour (OMF) + water were tested to inhibit the growth of A. parasiticus and AFs production in fresh pizza crust after 30 d. The antimicrobial and anti-aflatoxin activities were compared to a control group (no antimicrobial treatment) and to a group added with commercial preservatives (sorbic acid + sodium propionate). A. parasiticus growth was only inhibited after 30 d by AITC in filter paper at 5 μL/L and 10 μL/L, AITC sachet at 5 μL/L and 10 μL/L and OMF sachet at 850 mg + 850 μL of water. However, AFs production was inhibited by all antimicrobial treatments in a dose-dependent manner. More importantly, AITC in a filter paper at 10 μL/L, AITC sachet at 10 μL/L, OMF sachet at 850 mg + 850 μL of water and sorbic acid + sodium propionate at 0.5-2.0 g/Kg completely inhibited AFs formation. The use of AITC in active packaging devices could be a natural alternative to avoid the growth of mycotoxinogenic fungi in refrigerated bakery products in substitution of common commercial preservatives.

  16. Local post-harvest practices associated with aflatoxin and fumonisin contamination of maize in three agro ecological zones of Tanzania.

    PubMed

    Kamala, Analice; Kimanya, Martin; Haesaert, Geert; Tiisekwa, Bendantuguka; Madege, Richard; Degraeve, Szanne; Cyprian, Cypriana; De Meulenaer, Bruno

    2016-01-01

    A survey was undertaken of a total of 120 farmers, 40 from each of the three studied agro-ecological zones of Tanzania, to determine local post-harvest management practices associated with aflatoxin (AF) and fumonisin (FB) contamination of maize. Data on practices (collected using a structured questionnaire) and maize samples were obtained from each of the 120 farmers. FB and AF contamination in the samples were analysed by HPLC. A total of 45% and 85% of maize samples were positive for AF and FB respectively, with levels ranging from 0.1 to 269 μg kg(-1) for AF and from 49 to 18 273 μg kg(-1) for FBs. Significant differences in contamination level were observed among the three agro-ecological zones. Farmers in the three agro-ecological zones practised similar practices in varying degrees. Drying, sorting and protecting maize against insect infestation are practices that showed significant association with AF or FB contamination of maize. Drying maize on mat/raised platform, sorting (damaged, discoloured and moulded grains) and application of synthetic insecticides during storage are practices that were associated with less contamination of maize with AF and FB. The results can be used to advise on effective post-harvest strategies for prevention of AF and FB contamination of maize in rural Tanzania.

  17. Temporal Variation and Association of Aflatoxin B₁ Albumin-Adduct Levels with Socio-Economic and Food Consumption Factors in HIV Positive Adults.

    PubMed

    Jolly, Pauline E; Akinyemiju, Tomi F; Jha, Megha; Aban, Inmaculada; Gonzalez-Falero, Andrea; Joseph, Dnika

    2015-11-30

    The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure to aflatoxin (AF) among HIV positive individuals. We examined temporal variation in AFB₁ albumin adducts (AF-ALB) in HIV positive Ghanaians, and assessed the association with socioeconomic and food consumption factors. We collected socioeconomic and food consumption data for 307 HIV positive antiretroviral naive adults and examined AF-ALB levels at recruitment (baseline) and at six (follow-up 1) and 12 (follow-up 2) months post-recruitment, by age, gender, socioeconomic status (SES) and food consumption patterns. Generalized linear models were used to examine the influence of socioeconomic and food consumption factors on changes in AF-ALB levels over the study period, adjusting for other covariates. AF-ALB levels (pg/mg albumin) were lower at baseline (mean AF-ALB: 14.9, SD: 15.9), higher at six months (mean AF-ALB: 23.3, SD: 26.6), and lower at 12 months (mean AF-ALB: 15.3, SD: 15.4). Participants with the lowest SES had the highest AF-ALB levels at baseline and follow up-2 compared with those with higher SES. Participants who bought less than 20% of their food and who stored maize for less than two months had lower AF-ALB levels. In the adjusted models, there was a statistically significant association between follow up time and season (dry or rainy season) on AF-ALB levels over time (p = 0.04). Asymptomatic HIV-positive Ghanaians had high plasma AF-ALB levels that varied according to season, socioeconomic status, and food consumption patterns. Steps need to be taken to ensure the safety and security of the food supply for the population, but in particular for the most vulnerable groups such as HIV positive people.

  18. Esterified glucomannan improves aflatoxin-induced damage of sperm parameters during liquid storage of ram semen at 5°C.

    PubMed

    Ataman, Mehmet Bozkurt; Bucak, Mustafa Numan; Coyan, Kenan

    2014-06-01

    The aim of the present work was to study the effects of aflatoxin (AF) on sperm parameters in rams, and to determine the protective efficiency of esterified glucomannan (EG) co-administered with AF up to 96 h of the liquid storage of ram semen at 5°C. Thirty-two Merino rams (12-14 months old) were used. The animals were examined for their general health status. To ensure their adaptation to the environment and the new feeding regimen, a 15-day acclimatization programme was applied to the animals, prior to the start of the study. Experimental feeding was continued for ninety-two days. The experimental design consisted of four dietary treatments. The control group (C) was fed with commercial feed. The AF group was fed with commercial feed plus 250 μg/day of total AF. The EG group received commercial feed plus 2g/day of EG. The AF + EG group was given commercial feed plus 250 μg/day of total AF and 2g/day of EG. In the study, ejaculates were obtained from rams twice a week for 12 weeks, using an electro-ejaculator. After collected, the ejaculates were diluted with a skimmed milk extender, and stored at 5°C. Sperm motility and rates of abnormal and nonviable spermatozoa were determined for the different treatment groups at 5°C at 0, 24, 48, 72 and 96 h of liquid storage. During the first two weeks of the trial, the groups did not statistically differ from each other for sperm motility or rates of abnormal and nonviable spermatozoa at 0, 24, 48 and 96 h of storage. As from the third week, the short-term storage of semen produced statistically significant differences between the AF group and the other treatment groups for sperm parameters (p<0.05). The administration of aflatoxin was observed to have reduced sperm motility and to have increased the rates of abnormal and nonviable spermatozoa in comparison to the control group (p<0.05), while EG co-administered with AF was determined to have ameliorated the adverse effects of AF on sperm parameters, and this

  19. Temporal Variation and Association of Aflatoxin B1 Albumin-Adduct Levels with Socio-Economic and Food Consumption Factors in HIV Positive Adults

    PubMed Central

    Jolly, Pauline E.; Akinyemiju, Tomi F.; Jha, Megha; Aban, Inmaculada; Gonzalez-Falero, Andrea; Joseph, Dnika

    2015-01-01

    The association between aflatoxin exposure and alteration in immune responses observed in humans suggest that aflatoxin could suppress the immune system and work synergistically with HIV to increase disease severity and progression to AIDS. No longitudinal study has been conducted to assess exposure to aflatoxin (AF) among HIV positive individuals. We examined temporal variation in AFB1 albumin adducts (AF-ALB) in HIV positive Ghanaians, and assessed the association with socioeconomic and food consumption factors. We collected socioeconomic and food consumption data for 307 HIV positive antiretroviral naive adults and examined AF-ALB levels at recruitment (baseline) and at six (follow-up 1) and 12 (follow-up 2) months post-recruitment, by age, gender, socioeconomic status (SES) and food consumption patterns. Generalized linear models were used to examine the influence of socioeconomic and food consumption factors on changes in AF-ALB levels over the study period, adjusting for other covariates. AF-ALB levels (pg/mg albumin) were lower at baseline (mean AF-ALB: 14.9, SD: 15.9), higher at six months (mean AF-ALB: 23.3, SD: 26.6), and lower at 12 months (mean AF-ALB: 15.3, SD: 15.4). Participants with the lowest SES had the highest AF-ALB levels at baseline and follow up-2 compared with those with higher SES. Participants who bought less than 20% of their food and who stored maize for less than two months had lower AF-ALB levels. In the adjusted models, there was a statistically significant association between follow up time and season (dry or rainy season) on AF-ALB levels over time (p = 0.04). Asymptomatic HIV-positive Ghanaians had high plasma AF-ALB levels that varied according to season, socioeconomic status, and food consumption patterns. Steps need to be taken to ensure the safety and security of the food supply for the population, but in particular for the most vulnerable groups such as HIV positive people. PMID:26633502

  20. Food Safety Legislation Regarding Of Aflatoxins Contamination

    NASA Astrophysics Data System (ADS)

    Ketney, Otto

    2015-09-01

    The main objective of the European Union (EU) is to reduce certain contaminants in foodstuffs to acceptable levels. The occurrence of aflatoxin B1 in food was considered to be one of the most important issues of global food security to protect the health of humans and animals, over 100 nations have established maximum tolerable levels for aflatoxin in food. Although EU legislation covers many aspects of food safety was not legally establish an integrated framework that could effectively combat and cover all sectors of the food chain. Monitoring and reporting levels of aflatoxins after controls are essential actions that assist to identify potential risks to human health. The review process for aflatoxin regulations is a complex activity involving many factors and stakeholders.

  1. Aflatoxins in various food from Istanbul, Turkey.

    PubMed

    Hacıbekiroğlu, I; Kolak, U

    2013-01-01

    The present work reports the total aflatoxin and aflatoxin B1 levels in 62 food samples from Istanbul, Turkey. The total aflatoxin content in dried American cucumber, squash, tomato, okra and saffron samples was found to be 1.7 μg/kg. AFB1 levels in five dried vegetables (red bell pepper, American cucumber, squash, tomato and okra), two tea (linden and jasmine flower) and three spice samples (cardamom, galangal and saffron) were 1 μg/kg. Of the tested samples, 76% exceeded legal limits of total aflatoxin. The highest levels were determined in chestnut (232.9 μg/kg), nutmeg (206.1 μg/kg) and sumac (182.5 μg/kg). These findings confirm the existing knowledge that food should be regularly and effectively controlled.

  2. Aflatoxins as a cause of hepatocellular carcinoma.

    PubMed

    Kew, Michael C

    2013-09-01

    Aflatoxins, metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, are frequent contaminants of a number of staple foods, particularly maize and ground nuts, in subsistence farming communities in tropical and sub-tropical climates in sub-Saharan Africa, Eastern Asia and parts of South America. Contamination of foods occurs during growth and as a result of storage in deficient or inappropriate facilities. These toxins pose serious public health hazards, including the causation of hepatocellular carcinoma by aflatoxin B1. Exposure begins in utero and is life-long. The innocuous parent molecule of the fungus is converted by members of the cytochrome p450 family into mutagenic and carcinogenic intermediates. Aflatoxin-B1 is converted into aflatoxin B1-8,9 exo-epoxide, which is in turn converted into 8,9-dihydroxy-8-(N7) guanyl-9-hydroxy aflatoxin B1 adduct. This adduct is metabolized into aflatoxin B1 formaminopyrimidine adduct. These adducts are mutagenic and carcinogenic. In addition, an arginine to serine mutation at codon 249 of the p53 tumor suppressor gene is produced, abrogating the function of the tumor suppressor gene, and contributing to hepatocarcinogenesis. Aflatoxin B1 acts synergistically with hepatitis B virus in causing hepatocellular carcinoma. A number of interactions between the two carcinogens may be responsible for this action, including integration of hepatitis B virus x gene and its consequences, as well as interference with nucleotide excision repair, activation of p21waf1/cip1, generation of DNA mutations, and altered methylation of genes. But much remains to be learnt about the precise pathogenetic mechanisms responsible for aflatoxin B1-induced hepatocellular carcinoma as well as the interaction between the toxin and hepatitis B virus in causing the tumor.

  3. Inhibitory effects of Ephedra major Host on Aspergillus parasiticus growth and aflatoxin production.

    PubMed

    Bagheri-Gavkosh, Shahrokh; Bigdeli, Mohsen; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

    2009-11-01

    This study was undertaken to evaluate the effect of Ephedra major Host, an important medicinal plant with various biological activities, on growth and aflatoxin (AF) production by Aspergillus parasiticus NRRL 2999. The fungus was cultured in yeast extract-sucrose (YES) broth, a conductive medium that supports AF production, in the presence of various concentrations of essential oil (EO), hexanic and methanolic extracts of plant aerial parts, fruits, and roots using microbioassay technique. After incubating for 96 h at 28 degrees C in static conditions, mycelial dry weight was determined as an index of fungal growth, and aflatoxin B(1) (AFB(1)) was measured using HPLC technique. Based on the obtained results, EO of plant aerial parts significantly inhibited fungal growth at the highest concentration of 1000 microg/ml without any obvious effect on AFB(1) production at all concentrations used. Among plant extracts tested, only methanolic extract of aerial parts and roots were found to inhibit fungal growth and AFB(1) production dose-dependently with an IC(50) value of 559.74 and 3.98 microg/ml for AFB(1), respectively. Based on the GC/MS data, the major components of E. major EO were bis (2-ethylhexyl) phthalate (42.48%), pentacosane (20.94%), docosane (14.64%), citronellol (5.15%), heptadecan (4.41%), cis-3-Hexen-1-ol benzoate (4.07%), and 7-Octen-2-ol (3.25%). With respect to the potent inhibition of fungal growth and AF production by E. major, this plant may be useful in protecting crops from both toxigenic fungal growth and AF contamination.

  4. Aflatoxin Control in Maize by Trametes versicolor

    PubMed Central

    Scarpari, Marzia; Bello, Cristiano; Pietricola, Chiara; Zaccaria, Marco; Bertocchi, Luigi; Angelucci, Alessandra; Ricciardi, Maria Rosaria; Scala, Valeria; Parroni, Alessia; Fabbri, Anna A.; Reverberi, Massimo; Zjalic, Slaven; Fanelli, Corrado

    2014-01-01

    Aspergillus flavus is a well-known ubiquitous fungus able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth, these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. The requirement of products with low impact on the environment and on human health, able to control aflatoxin production, has increased. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus both in vitro and in maize, was investigated. The goal was to propose an environmental loyal tool for a significant control of aflatoxin production, in order to obtain feedstuffs and feed with a high standard of quality and safety to enhance the wellbeing of dairy cows. The presence of T. versicolor, grown on sugar beet pulp, inhibited the production of aflatoxin B1 in maize by A. flavus. Furthermore, treatment of contaminated maize with culture filtrates of T. versicolor containing ligninolytic enzymes, showed a significant reduction of the content of aflatoxin B1. PMID:25525683

  5. Inhibition of Aflatoxin Production by Surfactants

    PubMed Central

    Rodriguez, Susan B.; Mahoney, Noreen E.

    1994-01-01

    The effect of 12 surfactants on aflatoxin production, growth, and conidial germination by the fungus Aspergillus flavus is reported. Five nonionic surfactants, Triton X-100, Tergitol NP-7, Tergitol NP-10, polyoxyethylene (POE) 10 lauryl ether, and Latron AG-98, reduced aflatoxin production by 96 to 99% at 1% (wt/vol). Colony growth was restricted by the five nonionic surfactants at this concentration. Aflatoxin production was inhibited 31 to 53% by lower concentrations of Triton X-100 (0.001 to 0.0001%) at which colony growth was not affected. Triton X-301, a POE-derived anionic surfactant, had an effect on colony growth and aflatoxin production similar to that of the five POE-derived nonionic surfactants. Sodium dodecyl sulfate (SDS), an anionic surfactant, and dodecyltrimethylammonium bromide, a cationic surfactant, suppressed conidial germination at 1% (wt/vol). SDS had no effect on aflatoxin production or colony growth at 0.001%. The degree of aflatoxin inhibition by a surfactant appears to be a function of the length of the hydrophobic and hydrophilic chains of POE-derived surfactants. Images PMID:16349144

  6. Aflatoxins and heavy metals in animal feed in Iran.

    PubMed

    Eskandari, M H; Pakfetrat, S

    2014-01-01

    The occurrence of aflatoxin (aflatoxin B1, aflatoxin B2, aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2)) and heavy metal (Pb, Cd, As and Hg) contamination was determined in 40 industrially produced animal feed samples which were collected from the southwest of Iran. The results indicated that 75% of samples were contaminated by four aflatoxins and the level of AFB1 and sum of aflatoxins were higher than the permissible maximum levels in Iran (5 and 20 µg kg(-1), respectively) in all feed samples. A positive correlation was found between four types of aflatoxins in all the tested samples (p < 0.01) and the positive correlation between AFG1 and AFG2 was significant (r(2) = 0.708). All feed samples had lead concentrations lower than the maximum EU limit, while 5%, 17% and 42.5% of feed samples had As, Cd and Hg concentrations higher than the maximum limits, respectively.

  7. 7 CFR 996.11 - Negative aflatoxin content.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that...

  8. 7 CFR 996.11 - Negative aflatoxin content.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that...

  9. 7 CFR 996.11 - Negative aflatoxin content.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that...

  10. 7 CFR 996.11 - Negative aflatoxin content.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that...

  11. 7 CFR 996.11 - Negative aflatoxin content.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that...

  12. Genetic transformation system for the aflatoxin-producing fungus Aspergillus flavus.

    PubMed Central

    Woloshuk, C P; Seip, E R; Payne, G A; Adkins, C R

    1989-01-01

    A heterologous transformation system was developed for Aspergillus flavus with efficiencies greater than 20 stable transformants per micrograms of DNA. Protoplasts of uracil-requiring strains of the fungus were transformed with plasmid and cosmid vectors containing the pyr-4 gene of Neurospora crassa. Transformants were selected for their ability to grow and sporulate on medium lacking uracil. Vector DNA appeared to integrate randomly into the genome of A. flavus with a tendency for multiple, tandem insertion. Transformants with single or multiple insertions were stable after five consecutive transfers on medium containing uracil. Uracil-requiring recipient strains were obtained either by UV-irradiating conidia and selecting colonies resistant to 5-fluoroorotic acid or by transferring the mutated pyr locus to strains by parasexual recombination. This is the first report of a transformation system for an aflatoxin-producing fungus. The transformation system and the availability of aflatoxin-negative mutants provide a new approach to studying the biosynthesis and regulation of aflatoxin. Images PMID:2495764

  13. Antifungal properties and inhibitory effects upon aflatoxin production of Thymus vulgaris L. by Aspergillus flavus Link.

    PubMed

    Kohiyama, Cássia Yumie; Yamamoto Ribeiro, Milene Mayumi; Mossini, Simone Aparecida Galerani; Bando, Erika; Bomfim, Natália da Silva; Nerilo, Samuel Botião; Rocha, Gustavo Henrique Oliveira; Grespan, Renata; Mikcha, Jane Martha Graton; Machinski, Miguel

    2015-04-15

    The antifungal and antiaflatoxigenic properties of Thymus vulgaris essential oil (TEO) were evaluated upon Aspergillus flavus "in vitro". Suspension containing 10(6) of A. flavus were cultivated with TEO in concentrations ranging from 50 to 500 μg/mL. TEO reached minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) at 250 μg/mL. Inhibition of ergosterol biosynthesis was detected at a concentration of 100 μg/mL of TEO. Morphological evaluation performed by both light microscopy and scanning electron microscopy showed that antifungal activity of TEO could be detected starting at a concentration of 50 μg/mL and the fungicide effect at a concentration of 250 μg/mL. TEO completely inhibited production of both B1 and B2 aflatoxins (AFB1 and AFB2) at a concentration of 150 μg/mL. This way, fungal biomass development and aflatoxin production were dependent on TEO concentration. Therefore, TEO was capable of controlling the growth of A. flavus and its production of aflatoxins.

  14. Isolation and identification of fungi from a meju contaminated with aflatoxins.

    PubMed

    Jung, Yu Jung; Chung, Soo Hyun; Lee, Hyo Ku; Chun, Hyang Sook; Hong, Seung Beom

    2012-12-01

    A home-made meju sample contaminated naturally with aflatoxins was used for isolation of fungal strains. Overall, 230 fungal isolates were obtained on dichloran rosebengal chloramphenicol (DRBC) and dichloran 18% glycerol (DG18) agar plates. Morphological characteristics and molecular analysis of a partial beta-tubulin gene and the internal transcribed spacer (ITS) of rDNA were used for the identification of the isolates. The fungal isolates were divided into 7 genera: Aspergillus, Eurotium, Penicillium, Eupenicillium, Mucor, Lichtheimia, and Curvularia. Three strains from 56 isolates of the A. oryzae/flavus group were found to be aflatoxigenic A. flavus, by the presence of the aflatoxin biosynthesis genes and confirmatory aflatoxin production by high-performance liquid chromatography (HPLC). The predominant isolate from DRBC plates was A. oryzae (42 strains, 36.2%), whereas that from DG18 was A. candidus (61 strains, 53.5%). Out of the 230 isolates, the most common species was A. candidus (34.3%) followed by A. oryzae (22.2%), Mucor circinelloides (13.0%), P. polonicum (10.0%), A. tubingensis (4.8%), and L. ramosa (3.5%). A. flavus and E. chevalieri presented occurrence levels of 2.2%, respectively. The remaining isolates of A. unguis, P. oxalicum, Eupenicillium cinnamopurpureum, A. acidus, E. rubrum, P. chrysogenum, M. racemosus, and C. inaequalis had lower occurrence levels of < 2.0%.

  15. Reduction of aflatoxins (B₁, B₂, G₁, and G₂) in soybean-based model systems.

    PubMed

    Lee, Jongin; Her, Jae-Young; Lee, Kwang-Geun

    2015-12-15

    The effects of chemical, physical, and cooking treatments on the reduction of aflatoxin B1 (AFB1), B2, G1, and G2 in soybean matrix were investigated. A HPLC-FLD with a Kobra cell system was used for the quantitative analysis of aflatoxins (AFs). To decrease the level of AFs during the soaking process, the contaminated soybeans were submerged in organic acid solutions. The reduction rates of AFB1 in 1.0N citric acid, lactic acid, succinic acid, and tartaric acid for 18h were 94.1%, 92.7%, 62.0%, and 95.1%, respectively. In the case of pH and autoclave treatment, the level of AFB1 was significantly decreased during autoclaving process at pH 7.4, 9.0, and 11.1, compared with the non-autoclaved samples (p<0.05). In the case of physical treatment, the heating process at 100 and 150°C for 90min significantly decreased the level of AFB1 by 41.9% and 81.2%, respectively (p<0.05). The reduction rate of AFB1 after cooking was 97.9% for soybean milk and 33.6% for steamed soybeans.

  16. Occurrence of aflatoxins in oilseeds providing cocoa-butter substitutes.

    PubMed

    Kershaw, S J

    1982-05-01

    Four oilseeds providing cocoa-butter substitutes--shea, pentadecima, illipe, and salseed--when tested as substrates for aflatoxin production by two strains of Aspergillus parasiticus, gave varying levels of aflatoxin. Aflatoxins were found at low levels occurring naturally in moldy shea-nuts, but none of 21 commercial shea-nut samples contained greater than 20 micrograms of aflatoxin B1 per kg.

  17. Inhibitory effects of Satureja hortensis L. essential oil on growth and aflatoxin production by Aspergillus parasiticus.

    PubMed

    Razzaghi-Abyaneh, Mehdi; Shams-Ghahfarokhi, Masoomeh; Yoshinari, Tomoya; Rezaee, Mohammad-Bagher; Jaimand, Kamkar; Nagasawa, Hiromichi; Sakuda, Shohei

    2008-04-30

    In an effort to screen the essential oils of some Iranian medicinal plants for novel aflatoxin (AF) inhibitors, Satureja hortensis L. was found as a potent inhibitor of aflatoxins B1 (AFB1) and G1(AFG1) production by Aspergillus parasiticus NRRL 2999. Fungal growth was also inhibited in a dose-dependent manner. Separation of the plant inhibitory substance(s) was achieved using initial fractionation of its effective part (leaf essential oil; LEO) by silica gel column chromatography and further separation by reverse phase-high performance liquid chromatography (RP-HPLC). These substances were finally identified as carvacrol and thymol, based on the interpretation of 1H and 13C NMR spectra. Microbioassay (MBA) on cell culture microplates contained potato-dextrose broth (PDB) medium (4 days at 28 degrees C) and subsequent analysis of cultures with HPLC technique revealed that both carvacrol and thymol were able to effectively inhibit fungal growth, AFB1 and AFG1 production in a dose-dependent manner at all two-fold concentrations from 0.041 to 1.32 mM. The IC50 values for growth inhibition were calculated as 0.79 and 0.86 mM for carvacrol and thymol, while for AFB1 and AFG1, it was reported as 0.50 and 0.06 mM for carvacrol and 0.69 and 0.55 mM for thymol. The results obtained in this study clearly show a new biological activity for S. hortensis L. as strong inhibition of aflatoxin production by A. parasiticus. Carvacrol and thymol, the effective constituents of S. hortensis L., may be useful to control aflatoxin contamination of susceptible crops in the field.

  18. Echinomycin biosynthesis.

    PubMed

    Sato, Michio; Nakazawa, Takehito; Tsunematsu, Yuta; Hotta, Kinya; Watanabe, Kenji

    2013-08-01

    Echinomycin is an antitumor antibiotic secondary metabolite isolated from streptomycetes, whose core structure is biosynthesized by nonribosomal peptide synthetase (NRPS). The echinomycin biosynthetic pathway was successfully reconstituted in Escherichia coli. NRPS often contains a thioesterase domain at its C terminus for cyclorelease of the elongating peptide chain. Those thioesterase domains were shown to exhibit significant substrate tolerance. More recently, an oxidoreductase Ecm17, which forms the disulfide bridge in triostin A, was characterized. Surprisingly, an unrelated disulfide-forming enzyme GliT for gliotoxin biosynthesis was also able to catalyze the same reaction, providing another example of broad substrate specificity in secondary metabolite biosynthetic enzymes. Those promiscuous catalysts can be a valuable tool in generating diversity in natural products analogs we can produce heterologously.

  19. 7 CFR 983.5 - Aflatoxin inspection certificate.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Aflatoxin inspection certificate. 983.5 Section 983.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING..., ARIZONA, AND NEW MEXICO Definitions § 983.5 Aflatoxin inspection certificate. Aflatoxin...

  20. 7 CFR 983.5 - Aflatoxin inspection certificate.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Aflatoxin inspection certificate. 983.5 Section 983.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing..., ARIZONA, AND NEW MEXICO Definitions § 983.5 Aflatoxin inspection certificate. Aflatoxin...

  1. 7 CFR 983.5 - Aflatoxin inspection certificate.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Aflatoxin inspection certificate. 983.5 Section 983.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING..., ARIZONA, AND NEW MEXICO Definitions § 983.5 Aflatoxin inspection certificate. Aflatoxin...

  2. Challenges facing the biological control strategy for eliminating aflatoxin contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Competition with Aspergillus flavus isolates incapable of aflatoxin production is currently the most widely used biocontrol method for reducing aflatoxin contamination of in maize and cottonseed where aflatoxin contamination is a persistent problem for human and animal health. The method involves sp...

  3. Single Aflatoxin Contaminated Corn Kernel Analysis with Fluorescence Hyperspectral Image

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are toxic secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, among others. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin leve...

  4. Developing resistance to aflatoxin in maize and cottonseed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    At this time, no “magic bullet” for solving the aflatoxin contamination problem in maize and cottonseed has been identified, so several strategies must be utilized simultaneously to ensure a healthy crop, free of aflatoxins. The most widely explored strategy for the control of aflatoxin contaminatio...

  5. Natural co-occurrence of aflatoxins and Fusarium mycotoxins (fumonisins, deoxynivalenol, nivalenol and zearalenone) in corn from Indonesia.

    PubMed

    Ali, N; Sardjono; Yamashita, A; Yoshizawa, T

    1998-01-01

    Sixteen corn samples collected from Indonesia were analysed for aflatoxins (AF), fumonisins (FM), trichothecenes and zearalenone (ZEA) using high-performance liquid chromatography and gas chromatography-mass spectrometry. AF were detected in 11 (69%) samples at a mean level of 119 ng/g (maximum 487 ng/g) and FM in all of the samples at a mean level of 895 ng/g (maximum 2970 ng/g). Deoxynivalenol (DON), nivalenol (NIV) and ZEA were each detected in two (12%) samples; 21 and 32 ng/g, 49 and 169 ng/g, and 11 and 12 ng/g, respectively. All of the AF-contaminated samples were co-contaminated with FM. Mycological study showed all of the AF-contaminated samples were infected with A. flavus/A. parasiticus, and the FM-contaminated samples were either infected with F. moniliforme (50%), F. proliferatum (12%), F. nygamai (6%) or F. decemcellulare (38%). Supportive mycological studies showed that Fusarium species isolated from Indonesian corn were capable of producing a mean level of 10,000 micrograms/g FM. Based on these results, the correlation between FM-producers and AF-producers on kernel infection and contamination of these mycotoxins in corn was discussed. This is the first report on the natural co-occurrence of AF and various Fusarium mycotoxins, including DON and NIV in corn from Indonesia, and also the first report on the natural occurrence of DON in corn from hot areas of Southeast Asia.

  6. Effect of Capsicum carotenoids on growth and aflatoxins production by Aspergillus flavus isolated from paprika and chilli.

    PubMed

    Santos, L; Kasper, R; Sardiñas, N; Marín, S; Sanchis, V; Ramos, A J

    2010-12-01

    The aim of this study was to determine the effect of a carotenoid mixture (Capsantal FS-30-NT), containing capsanthin and capsorubin, on growth and aflatoxins (AF) production of AF-producing Aspergillus flavus isolates. Each isolate, previously isolated from paprika and chilli, was inoculated on Czapek Yeast extract Agar (CYA) medium supplemented with different amounts of capsantal (0-1%) and incubated at 10, 15 and 25 °C during 21 days. Growth rates and lag phases were obtained, and AF production was determined at 7, 14 and 21 days. None of the isolates grew at 10 °C and one isolate (UdLTA 3.193) hardly grew at 15 °C. Capsantal addition had no effect over lag phases and growth rates at 15 °C. At 25 °C capsantal reduced growth rates and increased lag phases. However, the effect of capsantal on AF production was inconclusive, because it depended on temperature or time, and most of the times it was not significant. Low temperature has been a crucial factor in AF production, regardless of the capsantal concentration tested. Industrial storage temperature for paprika and chilli use to be approximately 10 °C, so if this temperature is maintained mould growth and AF production should be prevented.

  7. Limited survey for the occurrence of aflatoxins in cereals and poultry feeds from Rabat, Morocco.

    PubMed

    Zinedine, A; Juan, C; Soriano, J M; Moltó, J C; Idrissi, L; Mañes, J

    2007-04-01

    Fifty eight (58) samples of cereals for human consumption (20 corn flour, 17 wheat flour) and poultry feeds (n=21) purchased from popular markets of Rabat in Morocco were analyzed for aflatoxins (AF) by HPLC with immunoaffinity column (IAC) clean-up and fluorimetric detection. The incidence of AF in corn, wheat flour and poultry feeds was about 80, 17.6 and 66.6% respectively. High contamination levels were found in corn and poultry feeds samples. Levels of contamination of analyzed samples with AFB1 ranged from 0.23 to 11.2, 0.03 to 0.15 and 0.05 to 5.38 ng/g for corn, wheat and poultry feeds respectively. Results showed also that the contamination of 10% of samples of corn was higher than the limit set by EU regulations for AFB1 and total AF. This is the first report on the determination of AF in corn, wheat and poultry feeds from Morocco by HPLC and IAC.

  8. Transformation of Aspergillus parasiticus with a homologous gene (pyrG) involved in pyrimidine biosynthesis

    SciTech Connect

    Skory, C.D.; Horng, J.S.; Pestka, J.J.; Linz, J.E. )

    1990-11-01

    The lack of efficient transformation methods for aflatoxigenic Aspergillus parasiticus has been a major constraint for the study of aflatoxin biosynthesis at the genetic level. A transformation system with efficiencies of 30 to 50 stable transformants per {mu}g of DNA was developed for A. parasiticus by using homologous pyrG gene. The pyrG gene from A. parasiticus was isolated by in situ plaque hybridization of a lambda genomic DNA library. Uridine auxotrophs of A. parasiticus ATCC 36537, a mutant blocked in aflatoxin biosynthesis, were isolated by selection on 5-fluoroorotic acid following nitrosoguanidine mutagenesis. Isolates with mutations in the pyrG gene resulting in elimination of orotidine monophosphate (OMP) decarboxylase activity were detected by assaying cell extracts for their ability to convert ({sup 14}C)OMP to ({sup 14}C)UMP. Transformation of A. parasiticus pyrG protoplasts with the homologous pyrG gene restored the fungal cells to prototrophy. Enzymatic analysis of cell extracts of transformant clones demonstrated that these extracts had the ability to convert ({sup 14}C)OMP to ({sup 14}C)UMP. Southern analysis of DNA purified from transformant clones indicated that both pUC19 vector sequences and pyrG sequences were integrated into the genome. The development of this pyrG transformation system should allow cloning of the aflatoxin-biosynthetic genes, which will be useful in studying the regulation of aflatoxin biosynthesis and may ultimately provide a means for controlling aflatoxin production in the field.

  9. Genome-Wide Transcriptome Analysis of Cotton (Gossypium hirsutum L.) Identifies Candidate Gene Signatures in Response to Aflatoxin Producing Fungus Aspergillus flavus.

    PubMed

    Bedre, Renesh; Rajasekaran, Kanniah; Mangu, Venkata Ramanarao; Sanchez Timm, Luis Eduardo; Bhatnagar, Deepak; Baisakh, Niranjan

    2015-01-01

    Aflatoxins are toxic and potent carcinogenic metabolites produced from the fungi Aspergillus flavus and A. parasiticus. Aflatoxins can contaminate cottonseed under conducive preharvest and postharvest conditions. United States federal regulations restrict the use of aflatoxin contaminated cottonseed at >20 ppb for animal feed. Several strategies have been proposed for controlling aflatoxin contamination, and much success has been achieved by the application of an atoxigenic strain of A. flavus in cotton, peanut and maize fields. Development of cultivars resistant to aflatoxin through overexpression of resistance associated genes and/or knocking down aflatoxin biosynthesis of A. flavus will be an effective strategy for controlling aflatoxin contamination in cotton. In this study, genome-wide transcriptome profiling was performed to identify differentially expressed genes in response to infection with both toxigenic and atoxigenic strains of A. flavus on cotton (Gossypium hirsutum L.) pericarp and seed. The genes involved in antifungal response, oxidative burst, transcription factors, defense signaling pathways and stress response were highly differentially expressed in pericarp and seed tissues in response to A. flavus infection. The cell-wall modifying genes and genes involved in the production of antimicrobial substances were more active in pericarp as compared to seed. The genes involved in auxin and cytokinin signaling were also induced. Most of the genes involved in defense response in cotton were highly induced in pericarp than in seed. The global gene expression analysis in response to fungal invasion in cotton will serve as a source for identifying biomarkers for breeding, potential candidate genes for transgenic manipulation, and will help in understanding complex plant-fungal interaction for future downstream research.

  10. Non-linear relationships between aflatoxin B₁ levels and the biological response of monkey kidney vero cells.

    PubMed

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2013-08-14

    Aflatoxin-producing fungi contaminate food and feed during pre-harvest, storage and processing periods. Once consumed, aflatoxins (AFs) accumulate in tissues, causing illnesses in animals and humans. Most human exposure to AF seems to be a result of consumption of contaminated plant and animal products. The policy of blending and dilution of grain containing higher levels of aflatoxins with uncontaminated grains for use in animal feed implicitly assumes that the deleterious effects of low levels of the toxins are linearly correlated to concentration. This assumption may not be justified, since it involves extrapolation of these nontoxic levels in feed, which are not of further concern. To develop a better understanding of the significance of low dose effects, in the present study, we developed quantitative methods for the detection of biologically active aflatoxin B₁ (AFB1) in Vero cells by two independent assays: the green fluorescent protein (GFP) assay, as a measure of protein synthesis by the cells, and the microculture tetrazolium (MTT) assay, as a measure of cell viability. The results demonstrate a non-linear dose-response relationship at the cellular level. AFB1 at low concentrations has an opposite biological effect to higher doses that inhibit protein synthesis. Additional studies showed that heat does not affect the stability of AFB1 in milk and that the Vero cell model can be used to determine the presence of bioactive AFB1 in spiked beef, lamb and turkey meat. The implication of the results for the cumulative effects of low amounts of AFB1 in numerous foods is discussed.

  11. Non-Linear Relationships between Aflatoxin B1 Levels and the Biological Response of Monkey Kidney Vero Cells

    PubMed Central

    Rasooly, Reuven; Hernlem, Bradley; He, Xiaohua; Friedman, Mendel

    2013-01-01

    Aflatoxin-producing fungi contaminate food and feed during pre-harvest, storage and processing periods. Once consumed, aflatoxins (AFs) accumulate in tissues, causing illnesses in animals and humans. Most human exposure to AF seems to be a result of consumption of contaminated plant and animal products. The policy of blending and dilution of grain containing higher levels of aflatoxins with uncontaminated grains for use in animal feed implicitly assumes that the deleterious effects of low levels of the toxins are linearly correlated to concentration. This assumption may not be justified, since it involves extrapolation of these nontoxic levels in feed, which are not of further concern. To develop a better understanding of the significance of low dose effects, in the present study, we developed quantitative methods for the detection of biologically active aflatoxin B1 (AFB1) in Vero cells by two independent assays: the green fluorescent protein (GFP) assay, as a measure of protein synthesis by the cells, and the microculture tetrazolium (MTT) assay, as a measure of cell viability. The results demonstrate a non-linear dose-response relationship at the cellular level. AFB1 at low concentrations has an opposite biological effect to higher doses that inhibit protein synthesis. Additional studies showed that heat does not affect the stability of AFB1 in milk and that the Vero cell model can be used to determine the presence of bioactive AFB1 in spiked beef, lamb and turkey meat. The implication of the results for the cumulative effects of low amounts of AFB1 in numerous foods is discussed. PMID:23949006

  12. Aflatoxin B1 in common Egyptian foods.

    PubMed

    Selim, M I; Popendorf, W; Ibrahim, M S; el Sharkawy, S; el Kashory, E S

    1996-01-01

    Samples of common Egyptian foods (17 nuts and seeds, 10 spices, 31 herbs and medicinal plants, 12 dried vegetables, and 28 cereal grains) were collected from markets in Cairo and Giza. A portion of each sample was extracted with chloroform, and the concentrated extract was cleaned by passing through a silica gel column. Aflatoxin B1 was determined by reversed-phase liquid chromatography with UV detection. The highest prevalence of aflatoxin B1 was in nuts and seeds (82%), followed by spices (40%), herbs and medicinal plants (29%), dried vegetables (25%), and cereal grains (21%). The highest mean concentration of aflatoxin B1 was in herb and medicinal plants (49 ppb), followed by cereals (36 ppb), spices (25 ppb), nuts and seeds (24 ppb), and dried vegetables (20 ppb). Among nuts and seeds, the prevalence of aflatoxin B1 was highest (100%) in watermelon seeds, inshell peanuts, and unshelled peanuts. The lowest prevalence and concentrations were in hommos (garbanzo beans). The highest concentrations of aflatoxin B1 were detected in foods that had no potential for field contamination but required drying during processing and storage, such as pomegranate peel, watermelon seeds, and molokhia.

  13. Fungal and aflatoxin contamination of medicinal herbs.

    PubMed

    Rizzo, I; Varsavsky, E; Vedoya, G; Haidukowski, M; Frade, H; Chiale, C

    1998-06-01

    Since the consumption of aromatic and medicinal herbs has been increasing in the last years, the Argentinian Health Authorities are concerned to control the quality and security of them. Fungal and aflatoxin contamination are two parameters to be taken into account, to ensure the harmlessness of the phytomedicinal products. In 81 different samples, grouped in end products (EP), raw material (RM) and at harvest (SH), fungal flora (enumeration and identification) as well as naturalAspergillus flavus and aflatoxin occurrence were investigated. In all samples fungal counts fulfilled the international general recommendation limits (maximum 10(5) cfu/g). Predominant flora was made up by xerophilic species ofAspergillus(100%), byPeniciIlium (< 50%) and in less percentage byFusarium (5.6%). Among the Aspergilli, A.flavus was present in all the three groups of samples. Using a TLC method, 47% of A. flavus isolates were toxinogenic, producing aflatoxin B1 and B2. In herbs, 4.7% of RM samples were naturally contaminated with aflatoxins B1 and B2. Considering the carcinogenic activity of aflatoxins it is essential to regulate them in the raw material (vegetal drug).

  14. Fungal Aflatoxins Reduce Respiratory Mucosal Ciliary Function

    PubMed Central

    Lee, Robert J.; Workman, Alan D.; Carey, Ryan M.; Chen, Bei; Rosen, Phillip L.; Doghramji, Laurel; Adappa, Nithin D.; Palmer, James N.; Kennedy, David W.; Cohen, Noam A.

    2016-01-01

    Aflatoxins are mycotoxins secreted by Aspergillus flavus, which can colonize the respiratory tract and cause fungal rhinosinusitis or bronchopulmonary aspergillosis. A. flavus is the second leading cause of invasive aspergillosis worldwide. Because many respiratory pathogens secrete toxins to impair mucociliary immunity, we examined the effects of acute exposure to aflatoxins on airway cell physiology. Using air-liquid interface cultures of primary human sinonasal and bronchial cells, we imaged ciliary beat frequency (CBF), intracellular calcium, and nitric oxide (NO). Exposure to aflatoxins (0.1 to 10 μM; 5 to 10 minutes) reduced baseline (~6–12%) and agonist-stimulated CBF. Conditioned media (CM) from A. fumigatus, A. niger, and A. flavus cultures also reduced CBF by ~10% after 60 min exposure, but effects were blocked by an anti-aflatoxin antibody only with A. flavus CM. CBF reduction required protein kinase C but was not associated with changes in calcium or NO. However, AFB2 reduced NO production by ~50% during stimulation of the ciliary-localized T2R38 receptor. Using a fluorescent reporter construct expressed in A549 cells, we directly observed activation of PKC activity by AFB2. Aflatoxins secreted by respiratory A. flavus may impair motile and chemosensory functions of airway cilia, contributing to pathogenesis of fungal airway diseases. PMID:27623953

  15. Pseudomonas syringae type III effector HopAF1 suppresses plant immunity by targeting methionine recycling to block ethylene induction

    PubMed Central

    Washington, Erica J.; Mukhtar, M. Shahid; Finkel, Omri M.; Wan, Li; Kieber, Joseph J.; Dangl, Jeffery L.

    2016-01-01

    HopAF1 is a type III effector protein of unknown function encoded in the genomes of several strains of Pseudomonas syringae and other plant pathogens. Structural modeling predicted that HopAF1 is closely related to deamidase proteins. Deamidation is the irreversible substitution of an amide group with a carboxylate group. Several bacterial virulence factors are deamidases that manipulate the activity of specific host protein substrates. We identified Arabidopsis methylthioadenosine nucleosidase proteins MTN1 and MTN2 as putative targets of HopAF1 deamidation. MTNs are enzymes in the Yang cycle, which is essential for the high levels of ethylene biosynthesis in Arabidopsis. We hypothesized that HopAF1 inhibits the host defense response by manipulating MTN activity and consequently ethylene levels. We determined that bacterially delivered HopAF1 inhibits ethylene biosynthesis induced by pathogen-associated molecular patterns and that Arabidopsis mtn1 mtn2 mutant plants phenocopy the effect of HopAF1. Furthermore, we identified two conserved asparagines in MTN1 and MTN2 from Arabidopsis that confer loss of function phenotypes when deamidated via site-specific mutation. These residues are potential targets of HopAF1 deamidation. HopAF1-mediated manipulation of Yang cycle MTN proteins is likely an evolutionarily conserved mechanism whereby HopAF1 orthologs from multiple plant pathogens contribute to disease in a large variety of plant hosts. PMID:27274076

  16. Coconut as a Medium for the Experimental Production of Aflatoxin

    PubMed Central

    Arseculeratne, S. N.; De Silva, L. M.; Wijesundera, S.; Bandunatha, C. H. S. R.

    1969-01-01

    Fresh, grated coconut has been found to be an excellent medium for aflatoxin production by Aspergillus flavus. Under optimal conditions, yields of 8 mg of total aflatoxin per g of substrate were obtained. Continuous agitation of the growth medium under moist conditions at 24 C produced highest yields. Aflatoxin was assayed both biologically and chromatographically. The aflatoxin content of cultures varied biphasically with the duration of incubation. It is suggested that this pattern could result from the sequential operation of factors promoting aflatoxin formation on the one hand and a detoxifying mechanism on the other. Images PMID:5803632

  17. Transformation of adsorbed aflatoxin B1 on smectite at elevated temperatures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins cause liver damage and suppress immunity. Smectites can be used to reduce the bioavailability of aflatoxins through adsorption. To further reduce the toxicity of aflatoxins and to eliminate the treatments of aflatoxin-loaded smectites, degrading the adsorbed aflatoxin to nontoxic or less ...

  18. Detection and detoxification of aflatoxins: prevention of aflatoxicosis and aflatoxin residues with hydrated sodium calcium aluminosilicate.

    PubMed

    Phillips, T D; Clement, B A; Kubena, L F; Harvey, R B

    1990-01-01

    Our recent findings demonstrate that HSCAS can prevent aflatoxicosis in chickens and swine and significantly decreases the level of aflatoxin M1 residues in the milk of lactating dairy cattle. The basic mechanism for this action appears to involve sequestration of aflatoxin in the gastrointestinal tract and chemisorption (i.e., tight binding) to HSCAS which results in a reduction in aflatoxin bioavailability. Research is in progress to elucidate the specificity of HSCAS action and to construct a series of selective chemisorbents for mycotoxin control in livestock and poultry.

  19. Aflatoxins and ochratoxin A in maize of Punjab, Pakistan.

    PubMed

    Iram, Wajiha; Anjum, Tehmina; Abbas, Mateen; Khan, Abdul Muqeet

    2014-01-01

    Aflatoxin and ochratoxin levels were determined in maize samples collected from store houses of 15 districts belonging to three agro-ecological zones of Punjab, Pakistan. Toxins were extracted by Aflaochra immunoaffinity columns and analysed by high-performance liquid chromatography (HPLC). Mean moisture content of maize kernels was recorded above the safe storage level of 15%. Results indicated that aflatoxin B1 and B2 contamination was found in 97.3% and 78.9% of the collected samples, respectively. Aflatoxin G1, aflatoxin G2 and ochratoxin A were not detected in any sample. Among positive samples, 77.3% contained aflatoxin B1 and 28% aflatoxin B2, exceeding the legal limits as set by the European Union (EU) and the United States Food and Drug Administration (USFDA). It was concluded that a significant number of samples contained aflatoxin B1 and B2 above the legal limits.

  20. Classification of corn kernels contaminated with aflatoxins using fluorescence and reflectance hyperspectral image analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are secondary metabolites produced by certain fungal species of the Aspergillus genus. Aflatoxin contamination remains a problem in agricultural products due to its toxic and carcinogenic properties. Conventional chemical methods for aflatoxin detection are time-consuming and destructive....

  1. Effect of low levels of aflatoxin B₁ on performance, biochemical parameters, and aflatoxin B₁ in broiler liver tissues in the presence of monensin and sodium bentonite.

    PubMed

    Magnoli, A P; Monge, M P; Miazzo, R D; Cavaglieri, L R; Magnoli, C E; Merkis, C I; Cristofolini, A L; Dalcero, A M; Chiacchiera, S M

    2011-01-01

    Aflatoxins (AF) are a major problem in broiler production and are significant economic and public health burdens worldwide. A commercial sodium bentonite (Na-B) adsorbent was used to prevent the effect of AF [50 µg of aflatoxin B₁ (AFB₁)/kg of feed] in broiler productivity, biochemical parameters, macroscopic and microscopic liver changes, and AFB₁ liver residues. The influence of Na-B (0.3%) and monensin (MON, 100 mg/kg), alone or in combination, was investigated in depth. The dietary treatments were as follows: treatment (T) 1: basal diet (B); T2: B + MON; T3: B + Na-B; T4: B + Na-B + MON; T5: B + AFB₁; T6: B + AFB₁ + Na-B + MON; T7: B + AFB₁ + MON; T8: B + AFB₁ + Na-B. Birds were fed dietary treatments for 28 d (d 18 to 46). No significant differences (P < 0.05) were observed among treatments with respect to broiler performance, biochemical parameters, or relative liver weights. With the exception of T8, all livers showed histopathological alterations, with accumulation of fat vacuoles. The normal appearance of livers from T8 showed the protective effect of Na-B against aflatoxicosis. The residual AFB₁ levels in livers from T5 to T8 ranged from 0.2 to 1.0 ng/g and were higher in livers from T6 (P < 0.05). Results of this study indicate a competition between AFB₁ and MON for adsorption sites on Na-B when feed contains low levels of the toxin, indicating a nonselective adsorption capacity of this particular Na-B. In addition, significant levels of AFB₁ in livers indicate that this determination is an important technique not only for diagnosis of aflatoxicosis in broilers, but also for quality control of avian products.

  2. Capability of different non-nutritive feed additives on improving productive and physiological traits of broiler chicks fed diets with or without aflatoxin during the first 3 weeks of life.

    PubMed

    Attia, Y A; Allakany, H F; Abd Al-Hamid, A E; Al-Saffar, A A; Hassan, R A; Mohamed, N A

    2013-08-01

    An experiment was conducted to determine whether some non-nutritive feed additives (NNFA) could block the adverse effects of aflatoxin (AF) on growth performance and physiological parameters of Cobb broilers throughout the period from 1 to 21 day of age. There were eight treatments consisting of two levels of AF at 0 and 200 ppb and four NNFA within each AF level. These additives included mannan oligosaccharides (MOS) at 2 g/kg diet, hydrated sodium calcium aluminosilicate (HSCAS) at 2 g/kg diet and Lactobacillus acidophilus (Lac) at 2 g/kg diet. At 21 day of age, five chickens of each treatment were slaughtered to study dressing percentage and relative weight of inner organs and glands. AF had a significant negative effect on body weight gain (BWG), and feed intake, while impairing feed conversion ratio (FCR). Aflatoxin significantly increased percentage liver, lymphocyte (%), monocyte (%), serum triglyceride level, and the aspartate aminotransferase (AST), and alanine aminotransferase (ALT), concentrations while decreasing dressing percentage, intestinal percentage, white blood cells (WBCs), red blood cells (RBCs), haemoglobin (Hgb), packed cell volume (PCV), heterophil (%), heterophil/lymphocyte ratio, total serum protein and serum albumin. Aflatoxin adversely affected the morphology of the liver, bursa and the thymus. There was a significant interaction between AF and NNFA on the relative weights of liver, heart and intestine. Lac completely blocked the negative effects of AF on the percentage liver and the heart and partially on the intestine. In conclusion, Lac was most effective in reversing the adverse effects of AF on growth and FCR and on the percentage, functions and morphology of the liver. Hydrated sodium calcium aluminosilicate also improved the economic traits of broilers but was less effective than Lac and more effective than MOS.

  3. Production and characterization of aflatoxin B2a antiserum.

    PubMed Central

    Gaur, P K; Lau, H P; Pestka, J J; Chu, F S

    1981-01-01

    The specificity and sensitivity of antiserum elicited from rabbits against aflatoxin B2a-bovine serum albumin conjugates were characterized with a radioimmunoassay (RIA) and an enzyme-linked immunosorbent assay (ELISA). Aflatoxin B1 was first converted to aflatoxin B2a and then conjugated to bovine serum albumin and horseradish peroxidase by a reductive alkylation method. The antiserum was developed in New Zealand white rabbits by multiple-site injection with the aflatoxin B2a-bovine serum albumin conjugate. Antibody titers were determined by both RIA and ELISA. Competitive RIAs with various aflatoxin analogs indicated that the antiserum was most reactive with aflatoxin B1 and slightly cross-reactive with aflatoxins B2a, B2, and M1. Competitive ELISAs showed the antiserum to be equally specific for aflatoxins B2a and B12 and less reactive with aflatoxins B2 and M1. The relative sensitivities of RIA and ELISA for aflatoxin B1 quantitation were 100 and 10 pg per assay, respectively. PMID:7235694

  4. Aflatoxin levels in raw and processed hazelnuts in Turkey.

    PubMed

    Baltaci, C; Ilyasoğlu, H; Cavrar, S

    2012-01-01

    Aflatoxin levels in hazelnut samples obtained from exporter companies were monitored over a 3-year period. A total of 3188 samples of raw and processed hazelnuts were analysed using an HPLC method. The total aflatoxin content of the contaminated samples was in the range of 0.02-78.98 µg kg(-1) for hazelnut kernels, 0.07-43.59 µg kg(-1) for roasted hazelnut kernels, 0.02-39.17 µg kg(-1) for roasted sliced hazelnut kernels, and 0.02-11.20 µg kg(-1) for hazelnut purees, respectively, showing that the variations of aflatoxin contamination were very high. The results of aflatoxin analysis revealed that the aflatoxin contamination in the hazelnut samples was at a tolerable level. A total of 3147 samples were contaminated with aflatoxins, although below the legal limits. However, the aflatoxin contents of 41 samples exceeded the legal limits. Therefore, aflatoxin contents of hazelnuts should be monitored regularly to minimise the risk of aflatoxin hazard, and pre- and post-harvest strategies should be developed to prevent aflatoxin formation.

  5. 7 CFR 983.150 - Aflatoxin regulations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Aflatoxin regulations. 983.150 Section 983.150 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  6. 7 CFR 983.50 - Aflatoxin regulations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Aflatoxin regulations. 983.50 Section 983.50 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  7. 7 CFR 983.50 - Aflatoxin regulations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Aflatoxin regulations. 983.50 Section 983.50 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  8. Hematological Parameters and the State of Liver Cells of Rats After Oral Administration of Aflatoxin B1 Alone and Together with Nanodiamonds

    NASA Astrophysics Data System (ADS)

    Mogilnaya, O. A.; Puzyr, A. P.; Baron, A. V.; Bondar, V. S.

    2010-05-01

    Hematological parameters and the state of liver cells of rats were examined in vivo after the animals received aflatoxin B1 (AfB1) alone and together with modified nanodiamonds (MND) synthesized by detonation. The rats that had received the MND hydrosol had elevated leukocyte levels, mainly due to higher granulocyte counts and somewhat increased monocyte counts compared to control rats. Hematological parameters of the rats that had received AfB1 alone differed from those of the control rats in another way: total white blood cell counts were significantly lower due to the decreased lymphocyte counts. In rats that had consumed AfB1 with the MND hydrosol, changes in hematological parameters were less pronounced than in rats that had consumed either AfB1 or MND. Electron microscopy showed that hepatocytes of the rats that had received the MND hydrosol or AfB1 with the MND hydrosol contained elevated levels of lipid inclusions and lysosomes. Hyperplasia of the smooth endoplasmic reticulum (EPR) was revealed in liver specimens of the rats that had received AfB1. Results of the study suggest the conclusion about mutual mitigation of the effects of nanoparticles and the mycotoxin on rats blood and liver cells after AfB1 has adsorbed on MND.

  9. Banana peel: an effective biosorbent for aflatoxins.

    PubMed

    Shar, Zahid Hussain; Fletcher, Mary T; Sumbal, Gul Amer; Sherazi, Syed Tufail Hussain; Giles, Cindy; Bhanger, Muhammad Iqbal; Nizamani, Shafi Muhammad

    2016-05-01

    This work reports the application of banana peel as a novel bioadsorbent for in vitro removal of five mycotoxins (aflatoxins (AFB1, AFB2, AFG1, AFG2) and ochratoxin A). The effect of operational parameters including initial pH, adsorbent dose, contact time and temperature were studied in batch adsorption experiments. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and point of zero charge (pHpzc) analysis were used to characterise the adsorbent material. Aflatoxins' adsorption equilibrium was achieved in 15 min, with highest adsorption at alkaline pH (6-8), while ochratoxin has not shown any significant adsorption due to surface charge repulsion. The experimental equilibrium data were tested by Langmuir, Freundlich and Hill isotherms. The Langmuir isotherm was found to be the best fitted model for aflatoxins, and the maximum monolayer coverage (Q0) was determined to be 8.4, 9.5, 0.4 and 1.1 ng mg(-1) for AFB1, AFB2, AFG1 and AFG2 respectively. Thermodynamic parameters including changes in free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) were determined for the four aflatoxins. Free energy change and enthalpy change demonstrated that the adsorption process was exothermic and spontaneous. Adsorption and desorption study at different pH further demonstrated that the sorption of toxins was strong enough to sustain pH changes that would be experienced in the gastrointestinal tract. This study suggests that biosorption of aflatoxins by dried banana peel may be an effective low-cost decontamination method for incorporation in animal feed diets.

  10. Aspergillus section Flavi and aflatoxins in Algerian wheat and derived products.

    PubMed

    Riba, Amar; Bouras, Noureddine; Mokrane, Salim; Mathieu, Florence; Lebrihi, Ahmed; Sabaou, Nasserdine

    2010-10-01

    Wheat and its derivatives are a very important staple food for North African populations. The aim of this study was to analyze populations of Aspergillus section Flavi from local wheat based on aflatoxins (AFs), cyclopiazonic acid (CPA) and sclerotia production, and also to evaluate AFs-contaminated wheat collected from two different climatic regions in Algeria. A total of 108 samples of wheat were collected during the following phases: pre-harvest, storage in silos and after processing. The results revealed that among the Aspergillus species isolated, those belonging to section Flavi were predominant. Of the 150 strains of Aspergillus section Flavi isolated, 144 were identified as Aspergillus flavus and 6 as Aspergillus tamarii. We showed that 72% and 10% of the A. flavus strains produced AFs and CPA, respectively. Among the 150 strains tested, 60 produced amounts of AFB1 ranging from 12.1 to 234.6 microg/g of CYA medium. Also, we showed that most strains produced large sclerotia. AFB1was detected by HPLC in 56.6% of the wheat samples and derived products (flour, semolina and bran) with contamination levels ranging from 0.13 to 37.42 microg/kg.

  11. Targeting mycotoxin biosynthesis pathway genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chemical detoxification and physical destruction of aflatoxins in foods and feed commodities is mostly unattainable in a way that preserves the edibility of the food. Therefore, preventing mycotoxins in general and aflatoxins in particular from entering the food chain is a better approach. This requ...

  12. Aflatoxins contamination in Pakistani brown rice: a comparison of TLC, HPLC, LC-MS/MS and ELISA techniques.

    PubMed

    Iqbal, Javed; Asghar, Muhammad Asif; Ahmed, Aftab; Khan, Mobeen Ahmed; Jamil, Khalid

    2014-12-01

    Advancement in the field of analytical food-chemistry has explored various experimental techniques for aflatoxins (AFs) quantification. The present study was aimed to compare four different techniques; thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) for the analysis of aflatoxin B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) in brown rice (n = 120) being collected from Karachi, Pakistan. All the four assays provide precised, accurate and comparable results. However, some differences were observed. For instance, TLC, HPLC and LC-MS/MS methodologies offered the advantage of the quantification of individual toxins in contrast to ELISA technique. The contamination ranges of AFB₁/AFB₂ as determined by TLC, HPLC and LC-MS/MS were 1.18-9.97/0.59-1.52, 0.16-10.54/0.26-1.35 and 0.11-10.88/0.38-1.48 µg/kg, respectively. However, AFG₁ and AFG₂ were not detected in any tested samples. Furthermore, owing to low-detection limit and sensitivity, HPLC and LC-MS/MS methodologies have identified greater number of contaminated samples in comparison to TLC and ELISA techniques. The overall average results of total AFs as provided by HPLC (3.79 µg/kg) and LC-MS/MS (3.89 µg/kg) were found higher in comparison to TLC (3.68 µg/kg) and ELISA (3.70 µg/kg). On the basis of achieved results, it was concluded that TLC, HPLC, LC-MS/MS and ELISA techniques are valuable tool for the quantification of AFs in cereals and grains. Furthermore, HPLC and LC-MS/MS techniques offer an added advantage for the detection of AFs in diminutive levels.

  13. In vitro effect of some fungicides on growth and aflatoxins production by Aspergillus flavus isolated from Capsicum powder.

    PubMed

    Santos, L; Marin, S; Sanchis, V; Ramos, A J

    2011-01-01

    The aim of this study was to determine the effect of some pre-harvest fungicides on growth and aflatoxin (AF) production of three Aspergillus flavus strains found in Capsicum powder. Each isolate, previously isolated from paprika, chilli and smoked paprika, was inoculated on yeast extract sucrose agar and on a 3% paprika extract agar medium supplemented with different fungicides and incubated at 20 and 30°C during 7 days. Growth measurements were obtained on days 3, 5 and 7, and the AF production was determined on day 7. The significance of the effects of the factors (strain, medium, temperature, time and fungicides) and their interaction over colony diameter and AF production was determined. Temperature constrained the effectiveness of fungicides in reducing growth, the fungicides being most effective at 20°C. The efficacy of the fungicides over AF production depended on the medium used and temperature. The most effective fungicides in inhibiting growth and AF production, regardless of the strain tested or applied conditions, were tebuconazole 25% and mancozeb 80% applied at a concentration of 0.75 and 3.5 g l(-1), respectively. Care should thus be taken in the choice of a suitable fungicide because their effectiveness may depend on intra-specific variation and temperature. Moreover, it is necessary to take into account that the most efficient fungicide in reducing growth is not always the best choice for pre-harvest treatments because it may promote AF production. Thus, the best fungicide is the one that can simultaneous prevent growth and AF production.

  14. Theoretical characterization of aflatoxins and their phototoxic reactions

    NASA Astrophysics Data System (ADS)

    Guedes, Rita C.; Eriksson, Leif A.

    2006-05-01

    Key molecular properties are calculated for the 8 most common aflatoxins at the B3LYP/6-31 + G(d,p) level. Special attention is given the possibility of aflatoxins to generate reactive oxygen species (ROS). It is concluded that the excited triplet states of the aflatoxins have properties that make them very potent ROS generators, in addition to direct photoinduced addition reactions. The elevated toxicity of aflatoxin B1 is discussed in terms of its lower ionization potential, and the coincidence of higher lying triplet states with dominant low-lying singlet excitations, which enables rapid intersystem crossing and decay along the triplet channel to the T 1 state.

  15. Aflatoxin contamination of commercial cottonseed in South Texas.

    PubMed

    Jaime-Garcia, Ramon; Cotty, Peter J

    2003-09-01

    ABSTRACT Aflatoxins are toxic fungal metabolites produced by several members of Aspergillus section Flavi. U.S. federal regulations limit the use of aflatoxin-contaminated cottonseed. Cottonseed with aflatoxin content of 20 ng/g or higher may not enter the profitable dairy market. Between 4,472 and 9,949 truckloads of cottonseed from 31 to 35 gins in South Texas were analyzed for aflatoxin content each year from 1997 to 2001 upon receipt at the Valley Co-op Oil Mill in Harlingen, TX. The highest levels of contamination occurred in 1999, with an average aflatoxin content of 112 ng/g and 66% of the cottonseed truckloads exceeding 20 ng/g. Years 1997 and 2000 had the lowest aflatoxin levels, averaging 24 ng/g, with the lowest incidence (16%) of the truckloads exceeding 20 ng/g in 1997. In general, aflatoxin contamination increased as the ginning season progressed. Rainfall after boll opening correlated highly with aflatoxin content, with rainfall in July explaining over 50% of the observed variability in aflatoxin content. South Texas was divided into four regions: Rio Grande Valley, Coastal Bend, Upper Coast, and Winter Garden. Geostatistical analyses revealed recurrent patterns of high and low contamination. The greatest contamination occurred from the central Coastal Bend region through the southern Upper Coast region. The Rio Grande Valley region experienced the least contamination during the study period.

  16. Regulatory considerations of aflatoxin contamination of food in Mexico.

    PubMed

    Guzmán-de-Peña, Doralinda; Peña-Cabriales, Juan José

    2005-01-01

    Aflatoxins are potent mutagenic and carcinogenic compounds produced by some strains of Aspergillus flavus, A. nomius, and A. parasiticus that are commonly present in the environment. Human populations, particularly those whose basic diet includes grains, are in risk to exposure to aflatoxins. It is thus necessary to monitor and control the contamination of food and feed by aflatoxins in both domestic and international trade. As large amounts of corn are imported into Mexico from the United States, this paper stresses the need to develop legislation and enforce standards to ensure trade of corn with the minimal amount of aflatoxin.

  17. Effect of pressure cooking on aflatoxin B1 in rice.

    PubMed

    Park, Je Won; Kim, Young-Bae

    2006-03-22

    The effect of pressure cooking on aflatoxin residues in polished rice was conducted to determine reduction of aflatoxin and mutagenic potentials. Three rice lots consisting of naturally contaminated, A. parasiticus-infested, and aflatoxin-spiked rice were steamed by ordinary and pressure cookers after they were washed with water. They were chemically analyzed for aflatoxins using a silica solid phase extraction tube and high-performance liquid chromatography (HPLC)-fluorescence detection (FD), and the presence of aflatoxin residues was confirmed using HPLC-electrospray ionization (ESI)-mass spectrometry (MS). An in vitro mutagenicity test with Salmonella typhimurium TA100 was employed to verify the results based on chemical analyses. The aflatoxin loss (78-88%) was notable after pressure cooking, and the reduction of aflatoxin-induced mutagenic potential (68-78%) was in good agreement with the HPLC results. It can be concluded that Koreans are safe from the aflatoxin-related risk if a pressure cooker is employed for cooking rice. The average Korean daily intake of aflatoxin through the consumption of staple rice would fall to 0.15 ng/kg bw/day, which would not exceed the established tolerable daily intake (0.40 ng/kg bw/day).

  18. Use of Cold Atmospheric Plasma to Detoxify Hazelnuts from Aflatoxins

    PubMed Central

    Siciliano, Ilenia; Spadaro, Davide; Prelle, Ambra; Vallauri, Dario; Cavallero, Maria Chiara; Garibaldi, Angelo; Gullino, Maria Lodovica

    2016-01-01

    Aflatoxins, produced by Aspergillus flavus and A. parasiticus, can contaminate different foodstuffs, such as nuts. Cold atmospheric pressure plasma has the potential to be used for mycotoxin detoxification. In this study, the operating parameters of cold atmospheric pressure plasma were optimized to reduce the presence of aflatoxins on dehulled hazelnuts. First, the effect of different gases was tested (N2, 0.1% O2 and 1% O2, 21% O2), then power (400, 700, 1000, 1150 W) and exposure time (1, 2, 4, and 12 min) were optimized. In preliminary tests on aflatoxin standard solutions, this method allowed to obtain a complete detoxification using a high power for a few minutes. On hazelnuts, in similar conditions (1000 W, 12 min), a reduction in the concentration of total aflatoxins and AFB1 of over 70% was obtained. Aflatoxins B1 and G1 were more sensitive to plasma treatments compared to aflatoxins B2 and G2, respectively. Under plasma treatment, aflatoxin B1 was more sensitive compared to aflatoxin G1. At the highest power, and for the longest time, the maximum temperature increment was 28.9 °C. Cold atmospheric plasma has the potential to be a promising method for aflatoxin detoxification on food, because it is effective and it could help to maintain the organoleptic characteristics. PMID:27128939

  19. A Prospective Study of Growth and Biomarkers of Exposure to Aflatoxin and Fumonisin during Early Childhood in Tanzania

    PubMed Central

    Shirima, Candida P.; Kimanya, Martin E.; Routledge, Michael N.; Srey, Chou; Kinabo, Joyce L.; Humpf, Hans-Ulrich; Wild, Christopher P.; Tu, Yu-Kang

    2014-01-01

    Background: Aflatoxin and fumonisin are toxic food contaminants. Knowledge about effects of their exposure and coexposure on child growth is inadequate. Objective: We investigated the association between child growth and aflatoxin and fumonisin exposure in Tanzania. Methods: A total of 166 children were recruited at 6–14 months of age and studied at recruitment, and at the 6th and 12th month following recruitment. Blood and urine samples were collected and analyzed for plasma aflatoxin–albumin adducts (AF-alb) using ELISA, and urinary fumonisin B1 (UFB1) using liquid chromatography–mass spectrometry, respectively. Anthropometric measurements were taken, and growth index z-scores were computed. Results: AF-alb geometric mean concentrations (95% CIs) were 4.7 (3.9, 5.6), 12.9 (9.9, 16.7), and 23.5 (19.9, 27.7) pg/mg albumin at recruitment, 6 months, and 12 months from recruitment, respectively. At these respective sampling times, geometric mean UFB1 concentrations (95% CI) were 313.9 (257.4, 382.9), 167.3 (135.4, 206.7), and 569.5 (464.5, 698.2) pg/mL urine, and the prevalence of stunted children was 44%, 55%, and 56%, respectively. UFB1 concentrations at recruitment were negatively associated with length-for-age z-scores (LAZ) at 6 months (p = 0.016) and at 12 months from recruitment (p = 0.014). The mean UFB1 of the three sampling times (at recruitment and at 6 and 12 months from recruitment) in each child was negatively associated with LAZ (p < 0.001) and length velocity (p = 0.004) at 12 months from recruitment. The negative association between AF-alb and child growth did not reach statistical significance. Conclusions: Exposure to fumonisin alone or coexposure with aflatoxins may contribute to child growth impairment. Citation: Shirima CP, Kimanya ME, Routledge MN, Srey C, Kinabo JL, Humpf HU, Wild CP, Tu YK, Gong YY. 2015. A prospective study of growth and biomarkers of exposure to aflatoxin and fumonisin during early childhood in Tanzania. Environ Health

  20. The use of regenerated immunoaffinity columns for aflatoxins B1, B2, G1 and G2 in peanut confection.

    PubMed

    Iha, Maria Helena; Mini, Camila Alessandra; Okada, Isaura Akemi; Briganti, Rita de Cássia; Trucksess, Mary W

    2017-02-03

    The aim of this study was to investigate the feasibility of using multitime-regenerated immunoaffinity column (IAC) for aflatoxins B1, B2, G1 and G2 in peanut confection. After each use, the IAC was washed immediately with phosphate-buffered saline and stored for >12h prior to reuse. The evaluation procedure consisted of using extracts of naturallycontaminated peanut confection (4 replicates), aflatoxin-free peanut confection (duplicates), and aflatoxin-free peanut confection sample spiked with the 4 aflatoxins (AFT) at 3 levels in 4 replicates. Each day, 18 test extracts were analyzed using 18 designated IACs. After each use, the IACs were regenerated and reused for corresponding test extracts on the following day. This procedure was repeated daily over the course of 9days. Analytical steps included passing the test extracts through the IACs, washing the columns with water, and eluting AFT with methanol. The eluates were diluted with water and were subjected to reversed phase LC separation, post-column photochemical derivatization and fluorescence detection. After eluting AFT, IACs were immediately regenerated by washing with phosphate buffer solution and storing overnight at 8°C for re-use the following day. Results were analyzed using ANOVA and Tukey tests. The numbers of reuse varied for each AF: For AFB1 AFB2, AFG1and AFG2 could be reused for 9, 6, 6 and 0 times, respectively. According to AOAC method performance criteria, recoveries ranging from 70% to 125% are considered acceptable at the spiking levels used in this study.

  1. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of "Suya Spices".

    PubMed

    Jonathan, Segun Gbolagade; Adeniyi, Mary Adejoke; Asemoloye, Michael Dare

    2016-01-01

    This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of "Suya spices." Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P < 0.05) with high protein (9.53% to 13.17%), fiber (9.27 to 13.17%), carbohydrate (46.27% to 50.90%), and ash (8.47% to 9.70%) contents but low moisture (9.03% to 9.47%) and fat (9.77% to 13.53%) contents. Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.). 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.). 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.). 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp.).

  2. Production of aflatoxin byAspergillus parasiticus and its control.

    PubMed

    Emara, H A

    1997-03-01

    The aim of the present work was to investigate the production of aflatoxin byAspergillus parasiticus and to find out the possible ways to control it. Of 40 food samples collected from Abha region, Saudi Arabia, only 25% were contaminated with aflatoxins. Oil-rich commodities had the highly contaminated commodities by fungi and aflatoxins while spices were free from aflatoxins.Bacillus megatertum andB cereus were suitable for microbiological assay of aflatoxins. Czapek's-Dox medium was found a suitable medium for isolation of fungi from food samples. The optimal pH for the growth ofA. parasiticus and its productivity of aflatoxin B1 was found at 6.0, while the best incubation conditions were found at 30°C for 10 days. D-glucose was the best carbon source for fungal growth, as well as aflatoxin production. Corn steep liquor, yeast extract and peptone were the best nitrogen sources for both fungal growth and toxin production (NH4)2HPO4 (1.55 gL(-1)) and NaNO2 (1.6 gL(-1)) reduced fungal growth and toxin production with 37.7% and 85%, respectively. Of ten amino acids tested, asparagine was the best for aflatoxin B1 production. Zn(2+) and Co(2+) supported significantly both fungal growth, as well as, aflatoxin B1 production at the different tested concentrations. Zn(2+) was effective when added toA. parasiticus growth medium at the first two days of the culture age. The other tested metal ions expressed variable effects depending on the type of ion and its concentration. Water activity (aw) was an important factor controlling the growth ofA. parasiticus and toxin production. The minimum aw for the fungal growth was 0.8 on both coffee beans and rice grains, while aw of 0.70 caused complete inhibition for the growth and aflatoxin B1 production. H2O2 is a potent inhibitor for growth ofA. parasiticus and its productivity of toxins. NaHCO3 and C6H5COONa converted aflatoxin B1 to water-soluble form which returned to aflatoxin B1 by acidity. Black pepper, ciliated heath

  3. The presence of aflatoxins and ochratoxin A in rice and rice products; and evaluation of dietary intake.

    PubMed

    Iqbal, Shahzad Zafar; Asi, Muhammad Rafique; Hanif, Usman; Zuber, Muhammad; Jinap, S

    2016-11-01

    In present study aflatoxins (AFs) and ochratoxin A (OTA) were analysed in 208 samples of rice and products collected from central areas of Punjab, Pakistan. The analysis was carried out using HPLC equipped with fluorescence detector. The results have shown that 35% of the samples were found contaminated with AFs, out of which 19% and 24% samples were found to be above the European Union (EU) maximum content for AFB1 and total AFs, respectively. About 19% samples were found contaminated with OTA and 14% samples were found to be above the EU maximum content. The highest mean level of AFB1 and total AFs were found in brown rice samples i.e. 8.91 and 12.4μg/kg, respectively. However, white rice samples have shown the highest mean level of OTA (8.50μg/kg) with highest level of 24.9μg/kg. The high mean dietary exposure 22.2 and 24.2ngkg(-1)bwday(-1) to AFB1 and OTA, respectively poses significant health hazard for local population.

  4. Controlling Aspergillus flavus and Aspergillus parasiticus growth and aflatoxin production in poultry feed using carvacrol and trans-cinnamaldehyde.

    PubMed

    Yin, Hsin-Bai; Chen, Chi-Hung; Kollanoor-Johny, Anup; Darre, Michael J; Venkitanarayanan, Kumar

    2015-09-01

    Aflatoxins (AF) are toxic metabolites primarily produced by molds, Aspergillus flavus and Aspergillus parasiticus. Contamination of poultry feed with AF is a major concern to the poultry industry due to severe economic losses stemming from poor performance, reduced egg production, and diminished egg hatchability. This study investigated the inhibitory effect of 2 generally regarded as safe (GRAS), natural plant compounds, namely carvacrol (CR) and trans-cinnamaldehyde (TC), on A. flavus and A. parasiticus growth and AF production in potato dextrose broth (PDB) and in poultry feed. In broth culture, PDB supplemented with CR (0%, 0.02%, 0.04% and 0.08%) or TC (0%, 0.005%, 0.01% and 0.02%) was inoculated with A. flavus or A. parasiticus (6 log CFU/mL), and mold counts and AF production were determined on days 0, 1, 3, and 5. Similarly, 200 g portions of poultry feed supplemented with CR or TC (0%, 0.4%, 0.8%, and 1.0%) were inoculated with each mold, and their counts and AF concentrations in the feed were determined at 0, 1, 2, 3, 4, 8, and 12 weeks of storage. Moreover, the effect of CR and TC on the expression of AF synthesis genes in A. flavus and A. parasiticus (aflC, nor1, norA, and ver1) was determined using real-time quantitative PCR (RT-qPCR). All experiments had duplicate samples and were replicated 3 times. Results indicated that CR and TC reduced A. flavus and A. parasiticus growth and AF production in broth culture and chicken feed (P<0.05). All tested concentrations of CR and TC decreased AF production in broth culture and chicken feed by at least 60% when compared to controls (P<0.05). In addition, CR and TC down-regulated the expression of major genes associated with AF synthesis in the molds (P<0.05). Results suggest the potential use of CR and TC as feed additives to control AF contamination in poultry feed.

  5. Aflatoxin production and oxidative stress in Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The colonization of crops by Aspergillus flavus results in the production of aflatoxins. Aflatoxin production is also exacerbated by abiotic stresses in the field. Here, we investigated the role of reactive oxygen species (ROS), which accumulate in plant tissues in response to drought and heat stres...

  6. Aflatoxin Accumulation in BT and non-BT Maize Testcrosses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The accumulation of aflatoxin, which is produced by the fungus, Aspergillus flavus Link: Fries, in maize is a chronic problem in the southeastern United States. Its presence in grain greatly reduces its value and marketability. Aflatoxin accumulation is frequently associated with high temperatures...

  7. Aflatoxins B and g contamination and aflatoxigenic fungi in nutmeg.

    PubMed

    Okano, Kiyoshi; Tomita, Tsuneyoshi; Ohzu, Yuji; Takai, Mitsuhiro; Ose, Ayaka; Kotsuka, Akiko; Ikeda, Naoko; Sakata, Junko; Kumeda, Yuko; Nakamura, Nobuya; Ichinoe, Masakatsu

    2012-01-01

    This study examined the distribution of aflatoxigenic fungi in 25 imported Indonesian nutmeg samples contaminated with aflatoxins Bs or Bs and Gs. The incidence of aflatoxigenic fungi in the samples contaminated with high levels of aflatoxin was significantly higher than that in the samples with low levels of the toxins(r=0.752). The aflatoxin production of isolates from the samples in cultures of YES broth was examined by means of TLC and HPLC analyses. The ability of isolates to produce aflatoxins did not necessarily correlate with the contamination levels of aflatoxin in the samples. We isolated aflatoxins B and G-producing fungi from 3 samples contaminated with the high levels of aflatoxins B and G. The aflatoxigenic isolates were identified as Aspergillus nomius and A. bombycis based on morphological characters, growth rates at 37°C and 42°C and also molecular-genetic methods. Our results indicate that these two species are mainly responsible for aflatoxin G contamination in nutmeg products.

  8. Sexual Reproduction in Aflatoxin-Producing Aspergillus nomius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are fungal secondary metabolites that exhibit carcinogenic, hepatotoxic and immunosuppressive properties. Aspergillus nomius is a potent producer of aflatoxins and was formerly considered to be strictly asexual in reproduction. In this research, mating-type genes MAT1-1 and MAT1-2 were ...

  9. Occurrence of aflatoxins in human foodstuffs in South Africa

    SciTech Connect

    Loetter, L.H.; Kroehm, H.J.

    1988-02-01

    Aflatoxins are toxic metabolites of Aspergillus spp and have been reported as contaminants in a number of foodstuffs, namely corn, rice, peanuts, and cereals. In the Republic of South Africa, aflatoxin levels in human foodstuffs are limited to a maximum of 10 ..mu..g/kg for the total and 5 ..mu..g/kg for aflatoxin B/sub 1/. During 1985 and 1986, samples of sorghum beer, sorghum cereal, peanuts, peanut butter and maize meal were purchased from supermarkets in Johannesburg and analyzed for aflatoxins. A total of 414 samples were analyzed during the survey. In 1985, roughly a third of the samples were contaminated with aflatoxins, with no levels in excess of the legal limit. In 1986 the percentage of contaminated samples rose significantly, but the levels of contamination remained low, with only one sample exceeding the legal maximum.

  10. Patulin & ergosterol: new quality parameters together with aflatoxins in hazelnuts.

    PubMed

    Ekinci, Raci; Otağ, Mustafa; Kadakal, Çetin

    2014-05-01

    Hazelnuts of three different categories, mouldy, hidden mould and sound (undamaged), were investigated for their contents of aflatoxins (B1, B2, G1 and G2), patulin, and ergosterol. Samples were obtained from five hazelnut processing plants located in a major hazelnut producing area in the Black Sea region in Turkey. All aflatoxins, patulin and ergosterol were determined by high performance liquid chromatography (HPLC). Sound hazelnuts were contaminated with trace or zero amounts of aflatoxins, patulin and ergosterol, so they posed no risk for the consumer when national and/or international regulatory limits were considered. Mouldy and hidden mould hazelnuts were contaminated with high (246-510ppb; 141-422ppb) aflatoxin levels, respectively. Aflatoxin B1 content was significantly correlated with the patulin and ergosterol contents in mouldy and hidden mould hazelnuts. However, there was no significant correlation between patulin and ergosterol contents of mouldy and hidden mould hazelnuts.

  11. Effect of Various Compounds Blocking the Colony Pigmentation on the Aflatoxin B1 Production by Aspergillus flavus

    PubMed Central

    Dzhavakhiya, Vitaly G.; Voinova, Tatiana M.; Popletaeva, Sofya B.; Statsyuk, Natalia V.; Limantseva, Lyudmila A.; Shcherbakova, Larisa A.

    2016-01-01

    Aflatoxins and melanins are the products of a polyketide biosynthesis. In this study, the search of potential inhibitors of the aflatoxin B1 (AFB1) biosynthesis was performed among compounds blocking the pigmentation in fungi. Four compounds—three natural (thymol, 3-hydroxybenzaldehyde, compactin) and one synthetic (fluconazole)—were examined for their ability to block the pigmentation and AFB1 production in Aspergillus flavus. All compounds inhibited the mycelium pigmentation of a fungus growing on solid medium. At the same time, thymol, fluconazole, and 3-hydroxybenzaldehyde stimulated AFB1 accumulation in culture broth of A. flavus under submerged fermentation, whereas the addition of 2.5 μg/mL of compactin resulted in a 50× reduction in AFB1 production. Moreover, compactin also suppressed the sporulation of A. flavus on solid medium. In vivo treatment of corn and wheat grain with compactin (50 μg/g of grain) reduced the level of AFB1 accumulation 14 and 15 times, respectively. Further prospects of the compactin study as potential AFB1 inhibitor are discussed. PMID:27801823

  12. A new AF gravitational instanton

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Teo, Edward

    2011-09-01

    It has long been conjectured that the Euclidean Schwarzschild and Euclidean Kerr instantons are the only non-trivial asymptotically flat (AF) gravitational instantons. In this Letter, we show that this conjecture is false by explicitly constructing a new two-parameter AF gravitational instanton with a U (1) × U (1) isometry group, using the inverse-scattering method. It has Euler number χ = 3 and Hirzebruch signature τ = 1, and its global topology is CP2 with a circle S1 removed appropriately. Various other properties of this gravitational instanton are also discussed.

  13. Value Added Processing of Aflatoxin Contaminated Peanut Meal: Aflatoxin Sequestration During Protein Extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of a bentonite clay, Astra-Ben 20A (AB20A), to sequester aflatoxin from contaminated (~110 ppb) peanut meal during protein extraction was studied. Aqueous peanut meal dispersions (10% w/w) were prepared varying pH, temperature, enzymatic hydrolysis conditions, and concentrations of AB2...

  14. Aflatoxin in pistachio nuts used as ingredients in Gaz sweets produced in Isfahan, Iran.

    PubMed

    Jahanmard, Elham; Azarani, Farzaneh; Sharifi, Mehran; Esfandiari, Zahra

    2014-01-01

    In Isfahan province of Iran, pistachio and almond are used specifically as ingredients to produce Gaz sweets, which are a typical product of Isfahan and exported to many countries. In this survey, 112 samples were gathered from different corresponding Gaz producers from 2007 to 2012 to evaluate the occurrence of aflatoxins (AF) in these products. Samples were analysed for AFB1, AFB2, AFG1 and AFG2 using immunoaffinity column clean-up (IC) and quantified by high-performance liquid chromatography (HPLC) with fluorescence detection. Among the samples analysed, AFB1 was detected in 13.4% of the samples above the maximum limit (ML) as set in Iran (5 µg/kg). Total AF (AFT) was above the ML in 9.8% of the samples. This study showed that full consideration is equally essential for nuts used as ingredients in special food products such as the Gaz sweets as for nuts for direct human consumption. It suggests a need for modifying the current trend of supervision.

  15. Multiclonal plastic antibodies for selective aflatoxin extraction from food samples.

    PubMed

    Bayram, Engin; Yılmaz, Erkut; Uzun, Lokman; Say, Rıdvan; Denizli, Adil

    2017-04-15

    Herein, we focused on developing a new generation of monolithic columns for extracting aflatoxin from real food samples by combining the superior features of molecularly imprinted polymers and cryogels. To accomplish this, we designed multiclonal plastic antibodies through simultaneous imprinting of aflatoxin subtypes B1, B2, G1, and G2. We applied Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and spectrofluorimetry to characterize the materials, and conducted selectivity studies using ochratoxin A and aflatoxin M1 (a metabolite of aflatoxin B1), as well as other aflatoxins, under competitive conditions. We determined optimal aflatoxin extraction conditions in terms of concentration, flow rate, temperature, and embedded particle amount as up to 25ng/mL for each species, 0.43mL/min, 7.0, 30°C, and 200mg, respectively. These multiclonal plastic antibodies showed imprinting efficiencies against ochratoxin A and aflatoxin M1 of 1.84 and 26.39, respectively, even under competitive conditions. Finally, we tested reusability, repeatability, reproducibility, and robustness of columns throughout inter- and intra-column variation studies.

  16. Photophysics and photochemistry of aflatoxins B1 and B2.

    PubMed

    Netto-Ferreira, J C; Heyne, B; Scaiano, J C

    2011-10-01

    Aflatoxins are mycotoxins produced by fungi of the genus Aspergillus, which is widely spread in the tropics and subtropics. To date, aflatoxin phototoxicity has been recognized, but the mechanism responsible for this phototoxicity has not been fully characterized. In the present paper, nanosecond laser flash photolysis studies allowed us to elucidate the photochemical processes undergone by two mycotoxins, namely aflatoxin B(1) and B(2), upon UV irradiation. In brief, photolysis (308 nm) of the aflatoxins leads to intersystem crossing, giving rise to their triplet excited state. The triplet state can readily be quenched by indole and hydroquinone, and also by molecular oxygen yielding singlet oxygen (singlet oxygen quantum yields of 0.51 and 0.59 were found for aflatoxin B(1) and B(2), respectively). In addition, our data indicate the ability of the two aflatoxins to photoionize upon 248 nm excitation. The photoionization quantum yield for aflatoxin B(1) and B(2) have been estimated to be 0.11 and 0.29, respectively.

  17. Quantitative Scrutinization of Aflatoxins in Different Spices from Pakistan

    PubMed Central

    Kashif, Aiza; Kanwal, Kinza; Khan, Abdul Muqeet; Abbas, Mateen

    2016-01-01

    The current research work aimed to access the contamination level of aflatoxins B1, B2, G1, and G2 in the household spices that are widely consumed in huge amounts. 200 different spice samples, 100 packed and 100 unpacked, were analyzed for the aflatoxins profile by HPLC with an incidence of 61.5% contamination out of which 53.66% samples exceed the EU limit. The results disclosed that the unpacked samples are more contaminated as compared to the packed samples except for white cumin seeds. Among packed and unpacked samples of spices, the maximum value of aflatoxins was detected in fennel, that is, 27.93 μg/kg and 67.04 μg/kg, respectively. The lowest concentration of aflatoxin was detected in cinnamon in packed form (0.79 μg/kg) and in the unpacked samples of white cumin seeds which is 1.75 μg/kg. Caraway seeds and coriander in its unpacked form showed positive results whereas black pepper (packed and unpacked) was found free from aflatoxins. This is the first report on the occurrence of aflatoxins in packed and unpacked samples of spices from Pakistan. To ensure safe consumption of spices, there should be constant monitoring of aflatoxin and more studies need to be executed with the intention of preventing mycotoxin accretion in this commodity. PMID:27781067

  18. Survey of aflatoxins in Kashkineh: A traditional Iranian food

    PubMed Central

    Mardani, M; Rezapour, S; Rezapour, P

    2011-01-01

    Background and Objectives Aflatoxins are mycotoxins produced by Aspergillus flavus and Aspergillus parasiticus that can contaminate human and animal foods, including corn, wheat, rice, peanuts, and many other crops resulting in the illness or death of human and animal consumers. The aim of this study was to detect aflatoxin B1, B2, G1, G2 and total aflatoxin in Kashkineh, a traditional Iranian food. Materials and Methods This survey was conducted to detect aflatoxins on 41 samples of Kashkineh. The samples were randomly collected from traditional bazaars and supermarkets of Khorramabad city of Iran. The presence and quantity of aflatoxins was determined by high performance liquid chromatography (HPLC). Results The average concentrations of AFB1, AFB2, AFG1, and AFG2 in all samples and in a mixed sample of all samples were not detectable (ND). The only sample that showed aflatoxin contamination was sample number 29 of which the AFB1 concentration was 0.64 ng/g. Conclusion Although some people believe Kashkineh is carcinogenic due to toxins, this study showed kashkineh is not contaminated with aflatoxins. PMID:22347598

  19. Chemical inactivation of aflatoxins in peanut protein ingredients.

    PubMed

    Natarajan, K R

    1992-01-01

    Aflatoxin contamination of peanuts has posed a threat to the peanut industry in utilizing peanuts as a source of a low-cost protein ingredient for food and feed. Although the best approach to containing the aflatoxin problem in peanuts is prevention, it appears that chemical inactivation of aflatoxin in contaminated raw material provides the best means to salvaging the contaminated material. Several chemical reagents have been investigated for their efficacy in destroying aflatoxins present in raw peanuts and defatted peanut meal. Using certain oxidizing agents such as NaOCl, H2O2, and benzoyl peroxide; bases such as ammonia, methylamine, and calcium hydroxide; and aldehydes such as formaldehyde, contaminated raw peanuts or defatted peanut meal have been demonstrated to yield peanut meals, protein isolates, and concentrates having trace amounts or nondetectable levels of aflatoxins. Processing conditions for inactivating aflatoxins using these chemicals were investigated. The chemical treatments had little effect on the physiochemical properties of the detoxified protein product. The advantages and disadvantages of using these chemicals for inactivation of aflatoxins are discussed.

  20. Occurrence of aflatoxin B1 in natural products

    PubMed Central

    Prado, Guilherme; Altoé, Aline F.; Gomes, Tatiana C. B.; Leal, Alexandre S.; Morais, Vanessa A. D.; Oliveira, Marize S.; Ferreira, Marli B.; Gomes, Mateus B.; Paschoal, Fabiano N.; von S. Souza, Rafael; Silva, Daniela A.; Cruz Madeira, Jovita E. G.

    2012-01-01

    The media claims for the consumption of natural resource-based food have gradually increased in both developing and developed countries. The interest in the safety of these products is partially due to the possible presence of toxigenic fungi acting as mycotoxin producers, such as aflatoxins produced during the secondary metabolism of Aspergillus flavus, A. parasiticus and A. nomius. Aflatoxins, mainly aflatoxin B1, are directly associated with liver cancer in human beings. This paper is aimed at evaluating the presence of aflatoxin B1 in a few vegetable drugs, dried plant extracts and industrialized products traded in 2010 in the city of Belo Horizonte, State of Minas Gerais, Brazil. The method used for the quantification of aflatoxin B1 was based on extraction through acetone:water (85:15), immunoaffinity column purification followed by separation and detection in high efficiency liquid chromatography. Under the conditions of analysis, the Limits of Detection and Quantification were 0.6 µg kg-1 and 1.0 µg kg-1 respectively. The complete sets of analyses were carried out in duplicate. Aflatoxin B1 was noticed in a single sample (< 1.0 µg kg-1). The results revealed low aflatoxin B1 contamination in the products under analysis. However, it is required to establish a broad monitoring program in order to obtain additional data and check up on the actual extension of contamination. PMID:24031973

  1. Biosynthesis: Imaging cell-wall biosynthesis live

    NASA Astrophysics Data System (ADS)

    Bugg, Timothy D. H.

    2013-01-01

    The biosynthesis of peptidoglycan is an important step in bacterial cell division and cell-wall maturation. Now it has been shown that fluorescent D-amino acids can be used to label the peptidoglycan cell wall of living bacteria, providing a new tool to study this important process.

  2. Ameliorative effects of thyme and calendula extracts alone or in combination against aflatoxins-induced oxidative stress and genotoxicity in rat liver.

    PubMed

    Abdel-Aziem, Sekena H; Hassan, Aziza M; El-Denshary, Ezzeldein S; Hamzawy, Mohamed A; Mannaa, Fathia A; Abdel-Wahhab, Mosaad A

    2014-05-01

    The aims of the current work were to evaluate the hepatoprotective effect of calendula flowers and/or thyme leave extracts on aflatoxins (AFs)-induced oxidative stress, genotoxicity and alteration of p53 bax and bcl2 gene expressions. Eighty male Sprague-Dawley rats were divided into eight equal groups including: the control group, the group fed AFs-contaminated diet (2.5 mg/kg diet) for 5 weeks, the groups treated orally with thyme and/or calendula extract (0.5 g/kg b.w) for 6 weeks and the groups pretreated orally with thyme and/or calendula extract 1 week before and during AFs treatment for further 5 weeks. Blood, liver and bone marrow samples were collected for biochemical analysis, gene expression, DNA fragmentation and micronucleus assay. The results showed that AFs induced significant alterations in oxidative stress markers, increased serum AFP and inflammatory cytokine, percentage of DNA fragmentation, the expression of pro-apoptotic gene p53 and bax accompanied with a decrease in the expression of bcl2. Animals treated with the extracts 1 week before AFs treatment showed a significant decrease in oxidative damage markers, micronucleated cells, DNA fragmentation and modulation of the expression of pro-apoptotic genes. These results suggested that both calendula and thyme extracts had anti-genotoxic effects due to their higher content of total phenolic compounds.

  3. Protein Biosynthesis in Mitochondria

    PubMed Central

    Kuzmenko, A. V.; Levitskii, S. A.; Vinogradova, E. N.; Atkinson, G. C.; Hauryliuk, V.; Zenkin, N.; Kamenski, P. A.

    2013-01-01

    Translation, that is biosynthesis of polypeptides in accordance with information encoded in the genome, is one of the most important processes in the living cell, and it has been in the spotlight of international research for many years. The mechanisms of protein biosynthesis in bacteria and in the eukaryotic cytoplasm are now understood in great detail. However, significantly less is known about translation in eukaryotic mitochondria, which is characterized by a number of unusual features. In this review, we summarize current knowledge about mitochondrial translation in different organisms while paying special attention to the aspects of this process that differ from cytoplasmic protein biosynthesis. PMID:24228873

  4. Protein biosynthesis in mitochondria.

    PubMed

    Kuzmenko, A V; Levitskii, S A; Vinogradova, E N; Atkinson, G C; Hauryliuk, V; Zenkin, N; Kamenski, P A

    2013-08-01

    Translation, that is biosynthesis of polypeptides in accordance with information encoded in the genome, is one of the most important processes in the living cell, and it has been in the spotlight of international research for many years. The mechanisms of protein biosynthesis in bacteria and in the eukaryotic cytoplasm are now understood in great detail. However, significantly less is known about translation in eukaryotic mitochondria, which is characterized by a number of unusual features. In this review, we summarize current knowledge about mitochondrial translation in different organisms while paying special attention to the aspects of this process that differ from cytoplasmic protein biosynthesis.

  5. Installation Restoration Program. Phase 1 - Records Search AAC-Northern Region, Galena AFS, Campion AFS, Cape Lisburne AFS, Fort Yukon AFS, Indian Mountain AFS, Kotzebue AFS, Murphy Dome AFS, and Tin City AFS

    DTIC Science & Technology

    1985-09-01

    registered with Defense Technical Information Center should direct requests for copies of this report to: Defense Technical Information Center Cameron Station ...Information Center should direct requests for copies of this report to: Defense Technical Information Center Cameron Station Alexandria, Virginia 22314 U’ B...Contract No. F08637 84 C0070. The locations of these installations are shown in Figure 1. INSTALLATION DESCRIPTION Galena AFS * Galena Air Force Station

  6. Nanoparticle-based immunosensors and immunoassays for aflatoxins.

    PubMed

    Wang, Xu; Niessner, Reinhard; Tang, Dianping; Knopp, Dietmar

    2016-03-17

    Aflatoxins are naturally existing mycotoxins produced mainly by Aspergillus flavus and Aspergillus parasiticus, present in a wide range of food and feed products. Because of their extremely high toxicity and carcinogenicity, strict control of maximum residue levels of aflatoxins in foodstuff is set by many countries. In daily routine, different chromatographic methods are used almost exclusively. As supplement, in several companies enzyme immunoassay-based sample testing as primary screening is performed. Recently, nanomaterials such as noble metal nanoparticles, magnetic particles, carbon nanomaterials, quantum dots, and silica nanomaterials are increasingly utilized for aflatoxin determination to improve the sensitivity and simplify the detection. They are employed either as supports for the immobilization of biomolecules or as electroactive or optical labels for signal transduction and amplification. Several nanoparticle-based electrochemical, piezoelectric, optical, and immunodipstick assays for aflatoxins have been developed. In this review, we summarize these recent advances and illustrate novel concepts and promising applications in the field of food safety.

  7. Aflatoxin in detannin coffee and tea and its destruction.

    PubMed

    Hasan, H A H

    2002-05-01

    The aflatoxins produced byAspergillus parasiticus var. globosus IMI 12090 in detannin-caffeinated coffee and black tea were five times more concentrated than in regular coffee and tea. The activity of caffeine and tannin on the fungus growth and aflatoxin production in liquid broth was tested at three levels: viz. 0.1, 0.3, and 0.6%. Tannin and caffeine induced 95% inhibition in aflatoxins at 0.3% and 0.6%, respectively. The antiaflatoxigenic properties of regular coffee and tea appear to be due to tannin, followed by caffeine. The roasting of contaminated coffee beans at 200 degrees C for 20 min is effective in the destruction of aflatoxins.

  8. Experimental aflatoxin production in home-made yoghurt.

    PubMed

    Blanco, J L; Domínguez, L; Gómez-Lucía, E; Garayzábal, J F; Goyache, J; Suárez, G

    1988-04-01

    Fungal growth and aflatoxin production by an aflatoxigenic strain during the manufacture of yoghurt are described. This completes previous studies which show that yoghurt may be a good substrate for aflatoxin production. Two factors were of special interest: (a) the temperature of the elaboration process (45 degrees C) and (b) the effect of lactic bacteria. Either during the elaboration of yoghurt or during its cooling from 45 degrees C to 4 degrees C, the necessary conditions required to start fungal growth are given; these are adequate enough for the synthesis of small quantities of aflatoxins. However our results do not clearly show that lactic bacteria have an influence on fungal growth and aflatoxin production.

  9. Sexual reproduction in aflatoxin-producing Aspergillus nomius

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual reproduction was examined in the aflatoxin-producing fungus Aspergillus nomius. Crosses between sexually compatible strains resulted in the formation of multiple nonostiolate ascocarps within stromata, which places the teleomorph in the genus Petromyces. Ascocarp and ascospore morphology in...

  10. Supercritical Fluid Extraction of Aflatoxin B 1 from Soil

    EPA Science Inventory

    This research describes the development of a Supercritical Fluid Extraction (SFE) method to recover aflatoxin B1 from fortified soil. The effects of temperature, pressure, modifier (identity and percentage), and extraction type were assessed. Using the optimized SFE conditions, ...

  11. Nitrogen fertilizer influence on aflatoxin contamination of corn in Louisiana.

    PubMed

    Tubajika, K M; Mascagni, H J; Damann, K E; Russin, J S

    1999-12-01

    Studies were conducted in 1997 and 1998 on a Gigger silt loam at the Macon Ridge Research Station at Winnsboro, LA, to determine the influence of nitrogen (N) rate, timing, and starter nitrogen fertilizer on aflatoxin contamination in corn. Fertilizer N (0, 50, 100, 150, 200, and 250 lb of N/acre), two timings (at planting and six-leaf stage), and starter N fertilizer (a control and 10 lb of N/acre applied in furrow) were evaluated. Application of starter, N rates, and the interaction of starter with N timing and N rates significantly affected aflatoxin levels. Rates of 50-250 lb of N/acre were 34-43% lower in aflatoxin contamination than plots receiving no N. The application of 10 lb of N/acre starter reduced the aflatoxin levels by 20% compared to the no-starter control.

  12. Effects of Aflatoxin on Germination and Growth of Lettuce

    PubMed Central

    Crisan, Eli V.

    1973-01-01

    The relative susceptibility of 30 cultivars of lettuce to inhibition by aflatoxin was studied. Seed germination was not inhibited by concentrations as high as 1,000 μg/ml in cultivar Imperial 44 or by 100 μg/ml in the remaining cultivars. Hypocotyl elongation was inhibited by 46 to 68% at a concentration of 100 μg of aflatoxin per ml. Seedlings exposed to aflatoxin did not become chlorotic. The similarity between the morphological reaction of plants to coumarin and aflatoxin suggests a common mode of action, but further studies of the physiological basis for the inhibitory reactions induced by these compounds will be necessary before such conclusions will be valid. PMID:4698861

  13. Transfer of aflatoxin B1 and fumonisin B1 from naturally contaminated raw materials to beer during an industrial brewing process.

    PubMed

    Pietri, A; Bertuzzi, T; Agosti, B; Donadini, G

    2010-10-01

    The aim of this research was to determine the fate of aflatoxins (AFs) and fumonisins (FBs) naturally occurring in raw materials (maize grit and malted barley) during four industrial brewing processes. The aflatoxin B(1) (AFB(1)) level in raw materials varied from 0.31 to 14.85 microg kg(-1), while the fumonisin B(1) (FB(1)) level (only in maize grit) varied from 1146 to 3194 microg kg(-1). The concentration in finished beer ranged from 0.0015 to 0.022 microg l(-1) for AFB(1) and from 37 to 89 microg l(-1) for FB(1); the other aflatoxins and fumonisin B(2) were not found in beer samples. The average percentage of toxins recovered in finished beer, referring to the amounts contained in raw materials, were 1.5% +/- 0.8% for AFB(1) and 50.7% +/- 4.7% for FB(1). These results were mainly due to the different solubility of the two mycotoxins during the mashing process. If raw materials comply with the limits fixed by European Commission Regulations, the contribution of a moderate daily consumption of beer to AFB(1) and FB(1) intake does not contribute significantly to the exposure of the consumer.

  14. Sensitivity of aflatoxin B/sub 1/ to ionizing radiation

    SciTech Connect

    Van Dyck, P.J.; Tobback, P.; Feys, M.; Van De Voorde, H.

    1982-06-01

    Aflatoxin B/sub 1/ in a 5-..mu..g/ml water solution was sensitive to ionizing radiation. Inactivation was assayed by the Ames microsome mutagenicity test and confirmed by thin-layer chromatography. Destruction of aflatoxin B/sub 1/ had already begun at 2.5 kilograys (kGy; 1 kGy = 0.1 Mrad), but a dose exceeding 10 kGy was necessary for total destruction.

  15. Aflatoxin and sterigmatocystin contamination of pistachio nuts in orchards.

    PubMed Central

    Sommer, N F; Buchanan, J R; Fortlage, R J

    1976-01-01

    Aspergillus flavus and A. versicolor were both shown to be weak pathogens of developing pistachio fruits, producing aflatoxin and sterigmatocystin, respectively. Aflatoxin concentrations approached those reported in cereal and legume seeds. Fungus lesions on the first hulls were followed by invasion of seeds despite the sclerified shell. Infections and mycotoxins present before harvest would presumably lead to further build-up after harvest if drying was slow or storage was under high humidity. PMID:823868

  16. Aflatoxins and food pathogens: impact of biologically active aflatoxins and their control strategies.

    PubMed

    Umesha, Sharanaiah; Manukumar, Honnayakanahalli Marichenne Gowda; Chandrasekhar, Bhadvelu; Shivakumara, Prahlad; Shiva Kumar, Jayanna; Raghava, Sri; Avinash, Prakasha; Shirin, Marahel; Bharathi, Tumkur R; Rajini, Sollepura B; Nandhini, Murali; Vinaya Rani, Govinda Gowda; Shobha, Mohankumar; Prakash, Harishchandra S

    2016-11-18

    Globally disease outbreaks as a result of the consumption of contaminated food and feedstuffs are a regular primary problem. The foremost elements contributing to contamination are microorganisms, particularly fungi, which produce low-molecular weight secondary metabolites, with demonstrated toxic properties that are referred to as mycotoxins. Aflatoxins contaminate agricultural commodities and may cause sickness or fatality in humans and animals. Moreover, poor conditions of storage and a deficiency in regulatory measures in food quality control aggravate the main issue. For that reason, mycotoxin-related illness of nutrition represents a major health hazard for local populations. Government policies should make regulations aiming to avoid the entry of aflatoxins into food stuffs. For consumer safety, control and management strategies should be developed and implemented by regulatory authorities. There is the need for attention from farmers, scientists, government and collaborative minds throughout the country to ensure aflatoxin-free food. The present review is informative not only for health-conscious consumers, but also for relevant authorities with respect to paving the way for future research aiming to fill the existing gaps in our knowledge with regard to mycotoxins and food security. © 2016 Society of Chemical Industry.

  17. Aflatoxin B1 and clinoptilolite in feed for laying hens: effects on egg quality, mycotoxin residues in livers, and hepatic mixed-function oxygenase activities.

    PubMed

    Rizzi, L; Simioli, M; Roncada, P; Zaghini, A

    2003-05-01

    Ninety-six laying hens were allocated to four groups administered different diets (group 0-0 received a complete diet, group 0-AF received a diet supplemented with 2.5 ppm of aflatoxin B1 [AFB1], group 2-0 received a diet supplemented with 2% clinoptilolite [CPL], and group 2-AF received a diet supplemented with 2% CPL and 2.5 ppm of AFB1) for 4 weeks to evaluate the effect of AFBI and/or CPL on egg quality and the ability of CPL to interact with the oral administration of AFB1. The possible effects of AFB1 on cytochrome P450-dependent hepatic mixed-function oxygenase (MFO) activities were also evaluated. Mycotoxin reduced yolk weight, while CPL influenced albumen percentage relative to that of eggs laid by chickens in group 0-AF Eggs laid by chickens in groups 0-AF and 2-AF had stronger shells and weighed less than the eggs of other groups. The eggs of treated groups were lighter in color than those of the control group (P < 0.01), and the tendency to yellowness in eggs was increased by CPL, probably through the affinity of red pigments for adsorbents and a consequent prevalence of yellow tonality. Color parameters might be connected with AFB1's interference with lipid metabolism and pigment deposition. The livers of hens in groups 0-AF and 2-AF showed very low mycotoxin concentrations that were significantly different (P < 0.01). The highest levels observed were those in the livers of the hens receiving the diet supplemented with the mycotoxin alone. AFB1 did not exert any significant effects on the hepatic MFO activities examined.

  18. Aflatoxin binders II: reduction of aflatoxin M1 in milk by sequestering agents of cows consuming aflatoxin in feed.

    PubMed

    Diaz, Duarte E; Hagler, Winston M; Blackwelder, John T; Eve, Julie A; Hopkins, Brinton A; Anderson, Kevin L; Jones, Frank T; Whitlow, Lon W

    2004-02-01

    Sequestering agents bind dietary aflatoxin B1 (AFB1) and reduce absorption from an animal's gastrointestinal tract. As a result, they protect an animal from the toxic effects of AFB1 and reduce transfer of the metabolite, aflatoxin M1 (AFM1), into milk. Three experiments, using late-lactation Holstein cows fed AFB1-contaminated feed, were conducted to evaluate several potential sequestering agents for their abilities to prevent or reduce the transmission of AFM1 into milk. Six agents previously tested in our laboratory for AFB1 binding in vitro were evaluated in these experiments. These were: SA-20, an activated carbon (AC-A); Astra-Ben-20, a sodium bentonite (AB-20); MTB-100, an esterified glucomannan (MTB-100); Red Crown, a calcium bentonite (RC); Flow Guard, a sodium bentonite (FG); and Mycrosorb, a sodium bentonite (MS). Five of the six sequestering agents significantly (P < 0.01) reduced AFM1 contamination of milk (AB-20, 61%; FG, 65%; MS, 50%; MTB-100, 59%; and RC, 31%); whereas, AC-A, activated carbon, had no effect on AFM1 transmission at 0.25% of feed. By the first milking (1 day after cows consumed contaminated feed), AFM1 appeared in milk, then reached maximum levels after three days, and was absent from milk within four days after AFB1 was removed from the feed. Sodium bentonites at 1.2% of feed showed good potential as AFB1 binders; MTB-100, a yeast cell wall product, was equally effective at 0.05% in feed. Potential AFB1 binding agents should be evaluated experimentally to demonstrate efficacy. Our data show that sequestering agents can reduce AFM1 in milk of cows fed AFB1-contaminated feed.

  19. Identification and functional characterization of an afsR homolog regulatory gene from Streptomyces venezuelae ATCC 15439.

    PubMed

    Maharjan, Sushila; Oh, Tae-Jin; Lee, Hei Chan; Sohng, Jae Kyung

    2009-02-01

    Sequencing analysis of a 5-kb DNA fragment from Streptomyces venezuelae ATCC 15439 revealed the presence of one 3.1-kb open reading frame (ORF), designated afsRsv. The deduced product of afsR-sv (1,056 aa) was found to have high homology with the global regulatory protein AfsR. Homology-based analysis showed that afsR-sv represents a transcriptional activator belonging to the Streptomyces antibiotic regulatory protein (SARP) family that includes an Nterminal SARP domain containing a bacterial transcriptional activation domain (BTAD), an NB-ARC domain, and a Cterminal tetratricopeptide repeat domain. Gene expression analysis by reverse transcriptase PCR (RT-PCR) demonstrated the activation of transcription of genes belonging to pikromycin production, when afsR-sv was overexpressed in S. venezuelae. Heterologous expression of the afsR-sv in different Streptomyces strains resulted in increased production of the respective antibiotics, suggesting that afsR-sv is a positive regulator of antibiotics biosynthesis.

  20. Penetration of aflatoxins through isolated human epidermis

    SciTech Connect

    Riley, R.T.; Kemppainen, B.W.; Norred, W.P.

    1985-01-01

    The purpose of this study was to determine if aflatoxin B1 (AFB1) could penetrate through isolated human epidermis (stratum corneum plus viable epidermis). ( UC)AFB1 (7.5-9.3 micrograms) was applied to the stratum corneum of epidermal disks mounted in Teflon diffusion cells. ( UC)AFB1 penetrated chemically unaltered through the isolated epidermis. Chloroform-extractable radioactivity accounted for 82.5 +/- 3.7% of the total penetrating radioactivity in the receptor fluid of the diffusion cells. The rate of penetration was very slow when experiments were conducted under nonoccluded conditions, but was approximately 40 times greater under conditions of occlusion. Penetration after 46 h was less than 0.05% and 3.41% of the applied dose under nonoccluded and occluded conditions, respectively. Total recovery expressed as a percentage of the applied radioactivity was 98.6 +/- 6.4%.

  1. Buckwheat achenes antioxidant profile modulates Aspergillus flavus growth and aflatoxin production.

    PubMed

    Chitarrini, G; Nobili, C; Pinzari, F; Antonini, A; De Rossi, P; Del Fiore, A; Procacci, S; Tolaini, V; Scala, V; Scarpari, M; Reverberi, M

    2014-10-17

    Buckwheat (Fagopyrum spp.) is a "pseudo-cereal" of great interest in the production of healthy foods since its flour, derived from achenes, is enriched with bioactive compounds and, due to the absence of gluten, may be used in composition of celiac diets. Amongst buckwheat species, F. tataricum achenes possess a larger amount of the antioxidant flavenol rutin than the common buckwheat F. esculentum. Ongoing climate change may favor plant susceptibility to the attack by pathogenic, often mycotoxigenic, fungi with consequent increase of mycotoxins in previously unexploited feeds and foodstuffs. In particular, Aspergillus flavus, under suitable environmental conditions such as those currently occurring in Italy, may produce aflatoxin B1 (AFB1), the most carcinogenic compound of fungal origin which is classified by IARC as Category 1. In this study, the viable achenes of two buckwheat species, F. tataricum (var. Golden) and F. esculentum (var. Aelita) were inoculated with an AFB1-producing A. flavus NRRL 3357 to analyze their relative performances against fungal invasion and toxin contamination. Notably, we sought the existence of a correlation between the amount of tocols/flavonols in the achenes of buckwheat, infected and non-infected with A. flavus, and to analyze the ability of the pathogen to grow and produce toxin during achene infection. Results suggest that achenes of F. tataricum, the best producer of antioxidant compounds in this study, are less susceptible to A. flavus infection and consequently, but not proportionally, to mycotoxin contamination compared with F. esculentum. Moreover, rutin-derived quercetin appears to be more efficient in inhibiting aflatoxin biosynthesis than the parent compound.

  2. 7 CFR 93.14 - Fees for aflatoxin analysis and fees for testing of other mycotoxins.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Fees for aflatoxin analysis and fees for testing of... Nuts, Corn and Other Oilseeds § 93.14 Fees for aflatoxin analysis and fees for testing of other mycotoxins. (a) The fee charged for any laboratory analysis for aflatoxins and other mycotoxins shall...

  3. 7 CFR 93.14 - Fees for aflatoxin analysis and fees for testing of other mycotoxins.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Fees for aflatoxin analysis and fees for testing of... Nuts, Corn and Other Oilseeds § 93.14 Fees for aflatoxin analysis and fees for testing of other mycotoxins. (a) The fee charged for any laboratory analysis for aflatoxins and other mycotoxins shall...

  4. Ear Rot, Aflatoxin Accumulation, and Fungal Biomass in Maize after Inoculation with Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin, a toxin produced by the fungus Aspergillus flavus Link:Fries, occurs naturally in maize (Zea mays L.). Aflatoxin is a potent human carcinogen and is toxic to livestock, pets, and wildlife. When contaminated with aflatoxin, the value of maize grain is markedly reduced. Eight germplasm l...

  5. Aflatoxin contamination of groundnut and maize in Zambia: observed and potential concentrations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize and groundnut, important staples in Zambia, are susceptible to aflatoxin-producing fungi. Aflatoxins are potent human carcinogens also associated with stunting and immunosuppression. Although health and economic burdens of aflatoxins are well known, patterns of contamination in maize and grou...

  6. Susceptibility to aflatoxin contamination among maize landraces from Mexico.

    PubMed

    Ortega-Beltran, Alejandro; Guerrero-Herrera, Manuel D J; Ortega-Corona, Alejandro; Vidal-Martinez, Victor A; Cotty, Peter J

    2014-09-01

    Maize, the critical staple food for billions of people, was domesticated in Mexico about 9,000 YBP. Today, a great array of maize landraces (MLRs) across rural Mexico is harbored in a living library that has been passed among generations since before the establishment of the modern state. MLRs have been selected over hundreds of generations by ethnic groups for adaptation to diverse environmental settings. The genetic diversity of MLRs in Mexico is an outstanding resource for development of maize cultivars with beneficial traits. Maize is frequently contaminated with aflatoxins by Aspergillus flavus, and resistance to accumulation of these potent carcinogens has been sought for over three decades. However, MLRs from Mexico have not been evaluated as potential sources of resistance. Variation in susceptibility to both A. flavus reproduction and aflatoxin contamination was evaluated on viable maize kernels in laboratory experiments that included 74 MLR accessions collected from 2006 to 2008 in the central west and northwest regions of Mexico. Resistant and susceptible MLR accessions were detected in both regions. The most resistant accessions accumulated over 99 % less aflatoxin B1 than did the commercial hybrid control Pioneer P33B50. Accessions supporting lower aflatoxin accumulation also supported reduced A. flavus sporulation. Sporulation on the MLRs was positively correlated with aflatoxin accumulation (R = 0.5336, P < 0.0001), suggesting that resistance to fungal reproduction is associated with MLR aflatoxin resistance. Results of the current study indicate that MLRs from Mexico are potentially important sources of aflatoxin resistance that may contribute to the breeding of commercially acceptable and safe maize hybrids and/or open pollinated cultivars for human and animal consumption.

  7. Relationship between Meloidogyne arenaria and Aflatoxin Contamination in Peanut

    PubMed Central

    Timper, P.; Wilson, D. M.; Holbrook, C. C.; Maw, B. W.

    2004-01-01

    Damaged and developing kernels of peanut (Arachis hypogaea) are susceptible to colonization by fungi in the Aspergillus flavus group which, under certain conditions, produces aflatoxins prior to harvest. Our objective was to determine whether infection of peanut roots and pods by Meloidogyne arenaria increases aflatoxin contamination of the kernels when peanut is subjected to drought stress. The experiment was a completely randomized 2-x-2 factorial with 6 replicates/treatment. The treatment factors were nematodes (plus and minus M. arenaria) and fungus (plus and minus A. flavus inoculum). The experiment was conducted in 2001 and 2002 in microplots under an automatic rain-out shelter. In treatments where A. flavus inoculum was added, aflatoxin concentrations were high (> 1,000 ppb) and not affected by nematode infection; in treatments without added fungal inoculum, aflatoxin concentrations were greater (P ≤ 0.05) in kernels from nematode-infected plants (1,190 ppb) than in kernels from uninfected plants (79 ppb). There was also an increase in aflatoxin contamination of kernels with increasing pod galling (r² = 0.83 in 2001, r² = 0.43 in 2002; P ≤ 0.04). Colonization of kernels by A. flavus increased with increasing pod galling (r² = 0.18; P = 0.04) in 2001 but not in 2002. Root-knot nematodes may have a greater role in enhancing aflatoxin contamination of peanut when conditions are not optimal for growth and aflatoxin production by fungi in the A. flavus group. PMID:19262803

  8. Aflatoxin exposure during the first 1000 days of life in rural South Asia assessed by aflatoxin B₁-lysine albumin biomarkers.

    PubMed

    Groopman, John D; Egner, Patricia A; Schulze, Kerry J; Wu, Lee S-F; Merrill, Rebecca; Mehra, Sucheta; Shamim, Abu A; Ali, Hasmot; Shaikh, Saijuddin; Gernand, Alison; Khatry, Subarna K; LeClerq, Steven C; West, Keith P; Christian, Parul

    2014-12-01

    Aflatoxin B1 is a potent carcinogen, occurring from mold growth that contaminates staple grains in hot, humid environments. In this investigation, aflatoxin B1-lysine albumin biomarkers were measured by mass spectrometry in rural South Asian women, during the first and third trimester of pregnancy, and their children at birth and at two years of age. These subjects participated in randomized community trials of antenatal micronutrient supplementation in Sarlahi District, southern Nepal and Gaibandha District in northwestern Bangladesh. Findings from the Nepal samples demonstrated exposure to aflatoxin, with 94% detectable samples ranging from 0.45 to 2939.30 pg aflatoxin B1-lysine/mg albumin during pregnancy. In the Bangladesh samples the range was 1.56 to 63.22 pg aflatoxin B1-lysine/mg albumin in the first trimester, 3.37 to 72.8 pg aflatoxin B1-lysine/mg albumin in the third trimester, 4.62 to 76.69 pg aflatoxin B1-lysine/mg albumin at birth and 3.88 to 81.44 pg aflatoxin B1-lysine/mg albumin at age two years. Aflatoxin B1-lysine adducts in cord blood samples demonstrated that the fetus had the capacity to convert aflatoxin into toxicologically active compounds and the detection in the same 2-year-old children illustrates exposure over the first 1000 days of life.

  9. Occurrence of aflatoxins in mahua (Madhuca indica Gmel.) seeds: synergistic effect of plant extracts on inhibition of Aspergillus flavus growth and aflatoxin production.

    PubMed

    Sidhu, O P; Chandra, Harish; Behl, H M

    2009-04-01

    Occurrence of aflatoxin in Madhuca indica Gmel. seeds was determined by competitive ELISA. Eighty percent of mahua seed samples were found to be contaminated with aflatoxin. Total aflatoxin content ranged from 115.35 to 400.54ppb whereas the concentration of AFB(1) was in the range of 86.43 to 382.45ppb. Mahua oil was extracted by cold press expeller and analysed for contamination of aflatoxin in both the oil and cake samples. Total aflatoxin and aflatoxin B(1) were 220.66 and 201.57ppb in oil as compared to that in cake samples where it was 87.55 and 74.35ppb, respectively. Various individual and combined plant extracts were evaluated for their efficacy against growth of Aspergillus flavus and aflatoxin production in vitro. Combination of botanicals were found to be more effective in controlling fungal growth and aflatoxin production than individual extracts. Results of the present study suggests that synergistic effect of plant extracts can be used for control of fungal growth and aflatoxin production. These natural plant products may successfully replace synthetic chemicals and provide an alternative method to protect mahua as well as other agricultural commodities of nutritional significance from toxigenic fungi such as A. flavus and aflatoxin production.

  10. The Shewanella algae strain YM8 produces volatiles with strong inhibition activity against Aspergillus pathogens and aflatoxins

    PubMed Central

    Gong, An-Dong; Li, He-Ping; Shen, Lu; Zhang, Jing-Bo; Wu, Ai-Bo; He, Wei-Jie; Yuan, Qing-Song; He, Jing-De; Liao, Yu-Cai

    2015-01-01

    Aflatoxigenic Aspergillus fungi and associated aflatoxins are ubiquitous in the production and storage of food/feed commodities. Controlling these microbes is a challenge. In this study, the Shewanella algae strain YM8 was found to produce volatiles that have strong antifungal activity against Aspergillus pathogens. Gas chromatography-mass spectrometry profiling revealed 15 volatile organic compounds (VOCs) emitted from YM8, of which dimethyl trisulfide was the most abundant. We obtained authentic reference standards for six of the VOCs; these all significantly reduced mycelial growth and conidial germination in Aspergillus; dimethyl trisulfide and 2,4-bis(1,1-dimethylethyl)-phenol showed the strongest inhibitory activity. YM8 completely inhibited Aspergillus growth and aflatoxin biosynthesis in maize and peanut samples stored at different water activity levels, and scanning electron microscopy revealed severely damaged conidia and a complete lack of mycelium development and conidiogenesis. YM8 also completely inhibited the growth of eight other agronomically important species of phytopathogenic fungi: A. parasiticus, A. niger, Alternaria alternate, Botrytis cinerea, Fusarium graminearum, Fusarium oxysporum, Monilinia fructicola, and Sclerotinia sclerotiorum. This study demonstrates the susceptibility of Aspergillus and other fungi to VOCs from marine bacteria and indicates a new strategy for effectively controlling these pathogens and the associated mycotoxin production during storage and possibly in the field. PMID:26500631

  11. Systems responses of rats to aflatoxin B1 exposure revealed with metabonomic changes in multiple biological matrices.

    PubMed

    Zhang, Limin; Ye, Yangfang; An, Yanpeng; Tian, Yuan; Wang, Yulan; Tang, Huiru

    2011-02-04

    Exposure to aflatoxins causes liver fibrosis and hepatocellular carcinoma posing a significant health risk for human populations and livestock. To understand the mammalian systems responses to aflatoxin-B1 (AFB1) exposure, we analyzed the AFB1-induced metabonomic changes in multiple biological matrices (plasma, urine, and liver) of rats using (1)H NMR spectroscopy together with clinical biochemistry and histopathologic assessments. We found that AFB1 exposure caused significant elevation of glucose, amino acids, and choline metabolites (choline, phosphocholine, and glycerophosphocholine) in plasma but reduction of plasma lipids. AFB1 also induced elevation of liver lipids, amino acids (tyrosine, histidine, phenylalanine, leucine, isoleucine, and valine), choline, and nucleic acid metabolites (inosine, adenosine, and uridine) together with reduction of hepatic glycogen and glucose. AFB1 further caused decreases in urinary TCA cycle intermediates (2-oxoglutarate and citrate) and elevation of gut microbiota cometabolites (phenylacetylglycine and hippurate). These indicated that AFB1 exposure caused hepatic steatosis accompanied with widespread metabolic changes including lipid and cell membrane metabolisms, protein biosynthesis, glycolysis, TCA cycle, and gut microbiota functions. This implied that AFB1 exposure probably caused oxidative-stress-mediated impairments of mitochondria functions. These findings provide an overview of biochemical consequences of AFB1 exposure and comprehensive insights into the metabolic aspects of AFB1-induced hepatotoxicity in rats.

  12. The Master Transcription Factor mtfA Governs Aflatoxin Production, Morphological Development and Pathogenicity in the Fungus Aspergillus flavus

    PubMed Central

    Zhuang, Zhenhong; Lohmar, Jessica M.; Satterlee, Timothy; Cary, Jeffrey W.; Calvo, Ana M.

    2016-01-01

    Aspergillus flavus produces a variety of toxic secondary metabolites; among them, the aflatoxins (AFs) are the most well known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing a number of economically-important crops, such as corn, cotton, peanut and tree nuts, and contaminating them with AFs. Molecular genetic studies in A. flavus could identify novel gene targets for use in strategies to reduce AF contamination and its adverse impact on food and feed supplies worldwide. In the current study, we investigated the role of the master transcription factor gene mtfA in A. flavus. Our results revealed that forced overexpression of mtfA results in a drastic decrease or elimination of several secondary metabolites, among them AFB1. The reduction in AFB1 was accompanied by a decrease in aflR expression. Furthermore, mtfA also regulates development; conidiation was influenced differently by this gene depending on the type of colonized substrate. In addition to its effect on conidiation, mtfA is necessary for the normal maturation of sclerotia. Importantly, mtfA positively affects the pathogenicity of A. flavus when colonizing peanut seeds. AF production in colonized seeds was decreased in the deletion mtfA strain and particularly in the overexpression strain, where only trace amounts were detected. Interestingly, a more rapid colonization of the seed tissue occurred when mtfA was overexpressed, coinciding with an increase in lipase activity and faster maceration of the oily part of the seed. PMID:26805883

  13. The surface-enhanced Raman spectra of aflatoxins: spectral analysis, density functional theory calculation, detection and differentiation.

    PubMed

    Wu, Xiaomeng; Gao, Simin; Wang, Jia-Sheng; Wang, Hongyan; Huang, Yao-Wen; Zhao, Yiping

    2012-09-21

    High-quality surface-enhanced Raman scattering (SERS) spectra of aflatoxin (AF) B(1), B(2), G(1) and G(2) have been acquired using silver nanorod (AgNR) array substrates fabricated by oblique angle deposition method. Significant vibrational peaks are identified on the argon plasma-cleaned substrates, and those peaks agree very well with the Raman spectra calculated by density function theory (DFT). The concentration-dependent SERS detection is also explored. The relationship between the concentration (C) of different AFs and the SERS intensity (I) of the Raman peak at Δν = 1592 cm(-1) is found to follow the general relationship I = AC(α), with α ranging from 0.32 to 0.46 for the four AFs. The limits of detection (LODs) reach 5 × 10(-5) mol L(-1) for AFB(1), 1 × 10(-4) mol L(-1) for AFB(2), and 5 × 10(-6) mol L(-1) for both AFG(1) and AFG(2) in bulk solution, or 6.17 × 10(-16) mol/1.93 × 10(-4) ng of AFB(1), 1.23 × 10(-15) mol/3.88 × 10(-4) ng for AFB(2), 6.17 × 10(-17) mol/2.03 × 10(-5) ng for AFG(1), and 6.17 × 10(-17) mol/2.04 × 10(-5) ng for AFG(2) per laser spot. Principal component analysis (PCA) is used to successfully differentiate these four different kinds of AFs at different concentrations up to their detection limits. The LODs obtained from PCA agree with the LODs obtained by using peak fitting method. With such a low detection limit and outstanding differentiation ability, we prove the possibility of utilizing the SERS detection system as a platform for highly sensitive mycotoxin detection.

  14. Antioxidant properties of Thymus vulgaris oil against aflatoxin-induce oxidative stress in male rats.

    PubMed

    El-Nekeety, Aziza A; Mohamed, Sherif R; Hathout, Amal S; Hassan, Nabila S; Aly, Soher E; Abdel-Wahhab, Mosaad A

    2011-06-01

    The leafy parts of thyme and its essential oil have been used in foods for the flavor, aroma and preservation and also in folk medicines. The aim of the current study was to determine the components of Thymus vulgaris L essential oil and to evaluate the protective effects of this oil against aflatoxin-induce oxidative stress in rats. Thirty six mature male Sprague-Dawley were divided into six treatment groups and treated for 2 weeks as follows: control group; the groups treated orally with low and high doses of T. vulgaris oil (5 and 7.5 mg/kg b.w.); the group fed AFs-contaminated diet (2.5 mg/kg diet) and the groups fed AFs-contaminated diet and treated orally with the oil at the two tested doses. Blood and tissue samples were collected at the end of treatment period for biochemical study and histological examination. The results indicated that the oil contains Carvarcrol (45 mg/g), Thymol (24.7 mg/g), β-Phellandrene (9.7 mg/g), Linalool (4.1 mg/g), Humuline (3.1 mg/g), α-Phellandrene (2.3 mg/g) and Myrcene (2.1 mg/g). However, α and β-pinene, Myrcene, α-thyjone, Tricyclene, 1, 8-cineole, and β-sabinene were found in lower concentrations. Treatment with AFs alone disturbs lipid profile in serum, decreases Total antioxidant capacity, increase creatinine, uric acid and nitric oxide in serum and lipid peroxidation in liver and kidney accompanied with a sever histological changes in the liver tissues. The oil alone at the two tested doses did not induce any significant changes in the biochemical parameters or the histological picture. The combined treatment showed significant improvements in all tested parameters and histological pictures in the liver tissues. Moreover, this improvement was more pronounced in the group received the high dose of the oil. It could be concluded that the essential oil of T. vulgaris has a potential antioxidant activity and a protective effect against AFs toxicity and this protection was dose dependent.

  15. Biosynthesis of Polyisoprenoids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The invention is a process for synthesis of a polymer with the same chemical structure as Natural Rubber (NR) obtained from Hevea brasiliensis and other plant species. The research collaborators recently proposed that NR biosynthesis proceeds via a carbocationic polymerization. Based on this theory...

  16. Aflatoxin: A 50-Year Odyssey of Mechanistic and Translational Toxicology

    PubMed Central

    Kensler, Thomas W.; Roebuck, Bill D.; Wogan, Gerald N.; Groopman, John D.

    2011-01-01

    Since their discovery 50 years ago, the aflatoxins have become recognized as ubiquitous contaminants of the human food supply throughout the economically developing world. The adverse toxicological consequences of these compounds in populations are quite varied because of a wide range of exposures leading to acute effects, including rapid death, and chronic outcomes such as hepatocellular carcinoma. Furthermore, emerging studies describe a variety of general adverse health effects associated with aflatoxin, such as impaired growth in children. Aflatoxin exposures have also been demonstrated to multiplicatively increase the risk of liver cancer in people chronically infected with hepatitis B virus (HBV) illustrating the deleterious impact that even low toxin levels in the diet can pose for human health. The public health impact of aflatoxin exposure is pervasive. Aflatoxin biomarkers of internal and biologically effective doses have been integral to the establishment of the etiologic role of this toxin in human disease through better estimates of exposure, expanded knowledge of the mechanisms of disease pathogenesis, and as tools for implementing and evaluating preventive interventions. PMID:20881231

  17. Aflatoxin synthesis in corn fields in Guanajuato, Mexico.

    PubMed

    Bucio-Villalobos, C M; Guzmán-de-Peña, D; Peña-Cabriales, J J

    2001-06-01

    Aflatoxin contamination of corn is an important problem internationally, particularly in tropical and subtropical conditions that favor infection and synthesis by Aspergillus. Environmental conditions (drought) and agronomic practices i.e. N fertilization have been reported as favorable to aflatoxin synthesis in the field. This study was undertaken to investigate whether the contamination of corn commonly observed in stored conditions in this important corn producing region of Mexico known as "El Bajio" is related to infection by Aspergillus under field conditions. Results using three corn hybrids of recognized susceptibility to infection showed that corn ears artificially inoculated in the field with a toxigenic strain of Aspergillus parasiticus presented a low content of aflatoxin ranging from 13.6 to 24.7 microg Kg(-1). No significant differences were observed between the hybrids tested. Similarly, N fertilization practices, 260 Kg N ha(-1), applied at sowing did not have an effect on the extent of the contamination observed of 6.2 and 19.3 mg of aflatoxin kg(-1) in natural infected and inoculated samples with A. parasiticus NRRL 2999, respectively. Our data suggest that the cases of aflatoxin contamination of corn in this part of Mexico are not related to infection occurring during the crops growing period but most probably to poor storage conditions of corn.

  18. Inactivation of aflatoxin B1 by using the synergistic effect of hydrogen peroxide and gamma radiation

    SciTech Connect

    Patel, U.D.; Govindarajan, P.; Dave, P.J. )

    1989-02-01

    Inactivation of aflatoxin B1 was studied by using gamma radiation and hydrogen peroxide. A 100-krad dose of gamma radiation was sufficient to inactivate 50 micrograms of aflatoxin B1 in the presence of 5% hydrogen peroxide, and 400 krad was required for total degradation of 100 micrograms of aflatoxin in the same system. Degradation of aflatoxin B1 was confirmed by high-pressure liquid chromatographic and thin-layer chromatographic analysis. Ames microsomal mutagenicity test showed loss of aflatoxin activity. This method of detoxification also reduces the toxin levels effectively in artificially contaminated groundnuts.

  19. Immobilization of anti-aflatoxin B1 antibody by UV polymerization of aniline and aflatoxin B1 detection via electrochemical impedance spectroscopy.

    PubMed

    Dinçkaya, Erhan; Kinik, Özer; Sezgintürk, Mustafa Kemal; Altuğ, Çağri; Akkoca, Aylin

    2012-12-01

    In the study, we investigated the practicality of the UV polymerization of aniline for anti-aflatoxin B1 antibody immobilization, and utilization of the resulting biosensor in the impedimetric determination of aflatoxin B1. The anti-aflatoxin B 1 antibody was physically immobilized on gold electrodes by UV polymerization of aniline at a fixed wavelength. The biosensor was based on specific interaction anti-aflatoxin B1 - aflatoxin B1 recognition and investigation of this recognition event by electrochemical impedance spectroscopy. A calibration curve was obtained in a linear detection range 1-20 ng/mL aflatoxin B1. Finally, the biosensor was applied to analysis of a real food sample.

  20. Simple method for screening aflatoxin-producing molds by UV photography.

    PubMed Central

    Yabe, K; Ando, Y; Ito, M; Terakado, N

    1987-01-01

    UV absorption by aflatoxins was monitored in GY agar medium by UV photography. In the UV photographs, aflatoxin-producing molds were identified as gray or black colonies, whereas aflatoxin-nonproducing molds appeared as white colonies. By cellophane transplantation experiments and silica gel thin-layer chromatography, the products absorbing UV light substantially were found to be mainly aflatoxins B1 and G1 excreted from the mold mycelium into the agar medium. UV absorption did not occur when the agar medium contained aflatoxin-noninducible carbon sources instead of glucose. Various inhibitors of aflatoxin production, such as dichlorovos and dimethyl sulfoxide, also decreased the intensity of UV absorption. These results indicate that this technique can be used as a simple, safe, and rapid method of screening aflatoxin-producing molds. Images PMID:3105453

  1. Evaluation of particulate air samplers for airborne aflatoxin B1

    SciTech Connect

    Silas, J.C.; Harrison, M.A.; Carpenter, J.A.

    1986-01-01

    Five air samplers (Millipore, all-glass impinger, centrifugal, Andersen, and absorbent cotton) were evaluated for their ability to collect airborne grain particles contaminated with aflatoxin B1. Corn dust containing 100 micrograms aflatoxin B1/g was aerosolized within a containment system. Each device sampled 100 I air, thus exchanging the air in the chamber two times. Aflatoxin B1 was extracted from all sampling matrices and was detected and quantitated with thin-layer chromatography and scanning fluorodensitometry. The highest efficiency was obtained with the Millipore sampler, while the efficiencies of the centrifugal and the cotton samplers were almost identical. Efficiency of an Andersen was less, with no toxin recovered from an all-glass impinger. Measurement of particle size was accomplished with the Andersen sampler.

  2. High Aflatoxin Production on a Chemically Defined Medium 1

    PubMed Central

    Reddy, T. V.; Viswanathan, L.; Venkitasubramanian, T. A.

    1971-01-01

    Aspergillus parasiticus ATCC 15517 produced 28 to 30 mg of aflatoxin per 100 ml of a medium containing sucrose, asparagine, and salts in stationary and shaken cultures. In the absence of asparagine in the medium, the toxin yields fell drastically, and the thin-layer chromatograms of the chloroform extracts of the cultures indicated the total absence of aflatoxin G1 and the presence of new intense blue and green fluorescent bands having RF values lower than aflatoxins. Initial pH was critical and had to be around 4.5 for good growth and high toxin production on this medium. Optimum concentrations of KH2PO4 and MgSO4·7H2O in the medium were much lower than those normally used in fungal growth media. PMID:5119206

  3. A mini review on aflatoxin exposure in Malaysia: past, present and future.

    PubMed

    Mohd-Redzwan, Sabran; Jamaluddin, Rosita; Abd-Mutalib, Mohd Sokhini; Ahmad, Zuraini

    2013-11-13

    This mini review article described the exposure of aflatoxin in Malaysia, including its presence in the foodstuffs and the detection of aflatoxin biomarkers in human biological samples. Historically, the exposure of aflatoxin in Malaysia can be dated in 1960s where an outbreak of disease in pig farms caused severe liver damage to the animals. Later, an aflatoxicosis case in Perak in 1988 was reported and caused death to 13 children, as up to 3 mg of aflatoxin was present in a single serving of contaminated noodles. Since then, extensive research on aflatoxin has been conducted in Malaysia. The food commodities such as peanuts, cereals, spices, and their products are the main commodities commonly found to be contaminated with aflatoxin. Surprisingly, some of the contaminated foods had levels greater than the permissible limit adopted by the Malaysian Food Regulation 1985. Besides, exposure assessment through the measurement of aflatoxin biomarkers in human biological samples is still in its infancy stage. Nevertheless, some studies had reported the presence of these biomarkers. In fact, it is postulated that Malaysians are moderately exposed to aflatoxin compared to those high risk populations, where aflatoxin contamination in the diets is prevalent. Since the ingestion of aflatoxin could be the integral to the development of liver cancer, the incidence of cancer attributable by dietary aflatoxin exposure in Malaysia has also been reported and published in the literatures. Regardless of these findings, the more important task is to monitor and control humans from being exposed to aflatoxin. The enforcement of law is insufficient to minimize human exposure to aflatoxin. Preventive strategies include agricultural, dietary, and clinical measures should be implemented. With the current research on aflatoxin in Malaysia, a global networking for research collaboration is needed to expand the knowledge and disseminate the information to the global scientific community.

  4. Aflatoxin M1 in Cow’s Milk: Method Validation for Milk Sampled in Northern Italy

    PubMed Central

    Bellio, Alberto; Bianchi, Daniela Manila; Gramaglia, Monica; Loria, Andrea; Nucera, Daniele; Gallina, Silvia; Gili, Marilena; Decastelli, Lucia

    2016-01-01

    Aflatoxins (AFs) are mycotoxins produced by some species of Aspergillus. In dairy cows, ingested AFB1 is metabolized into carcinogenic AFM1 which is eliminated through milk, thus posing a risk for consumer health. Here we describe the set, validation, and application of screening (ELISA) and confirmatory (HPLC) tests carried out on milk samples collected through official control of mycotoxin levels in northern Italy over a three-year period (2012–2014). The limit of detection (LOD) was set at 5 ppt (ng/kg) and 2 ppt for ELISA and HPLC, respectively, and the limit of quantification (LOQ) was 10 ppt for confirmatory HPLC. A total of 1668 milk samples were analyzed: ELISA identified 36 (2.2%) positive milk samples that were subsequently confirmed by HPLC. The level of AFM1 in the positive samples ranged between 18 ± 2 and 208 ± 27 ppt. Of the total samples, only eight (0.5%) were found non-compliant with the EU regulatory limit (50 ppt; range 74 ± 10 to 208 ± 27 ppt). Use of ELISA and HPLC tests in series allows for high-volume analysis of samples, thus saving time and money while guaranteeing high analytical precision and accuracy. PMID:26927175

  5. Relationships between in vivo and in vitro aflatoxin production: reliable prediction of fungal ability to contaminate maize with aflatoxins.

    PubMed

    Probst, Claudia; Cotty, Peter J

    2012-04-01

    Aflatoxins are highly carcinogenic mycotoxins frequently produced by Aspergillus flavus. Contamination of maize with aflatoxins imposes both economic and health burdens in many regions. Identification of the most important etiologic agents of contamination is complicated by mixed infections and varying aflatoxin-producing potential of fungal species and individuals. In order to know the potential importance of an isolate to cause a contamination event, the ability of the isolate to produce aflatoxins on the living host must be determined. Aflatoxin production in vitro (synthetic and natural media) was contrasted with in vivo (viable maize kernels) in order to determine ability of in vitro techniques to predict the relative importance of causal agents to maize contamination events. Several media types and fermentation techniques (aerated, non-aerated, fermentation volume) were compared. There was no correlation between aflatoxin production in viable maize and production in any of the tested liquid fermentation media using any of the fermentation techniques. Isolates that produced aflatoxins on viable maize frequently failed to produce detectable (limit of detection=1ppb) aflatoxin concentrations in synthetic media. Aflatoxin production on autoclaved maize kernels was highly correlated with production on viable maize kernels. The results have important implications for researchers seeking to either identify causal agents of contamination events or characterize atoxigenic isolates for biological control.

  6. Health Information in Somali (af Soomaali): MedlinePlus

    MedlinePlus

    ... af Soomaali (Somali) Bilingual PDF Health Information Translations Wildfires Wildfires - English Dabka duurka - af Soomaali (Somali) Multimedia Healthy Roads Media Wildfires - English Dabka duurka - af Soomaali (Somali) PDF Healthy ...

  7. Single aflatoxin contaminated corn kernel analysis with fluorescence hyperspectral image

    NASA Astrophysics Data System (ADS)

    Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Ononye, Ambrose; Brown, Robert L.; Cleveland, Thomas E.

    2010-04-01

    Aflatoxins are toxic secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, among others. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin levels in food and feed are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food and 100 ppb in feed for interstate commerce. Currently, aflatoxin detection and quantification methods are based on analytical tests including thin-layer chromatography (TCL) and high performance liquid chromatography (HPLC). These analytical tests require the destruction of samples, and are costly and time consuming. Thus, the ability to detect aflatoxin in a rapid, nondestructive way is crucial to the grain industry, particularly to corn industry. Hyperspectral imaging technology offers a non-invasive approach toward screening for food safety inspection and quality control based on its spectral signature. The focus of this paper is to classify aflatoxin contaminated single corn kernels using fluorescence hyperspectral imagery. Field inoculated corn kernels were used in the study. Contaminated and control kernels under long wavelength ultraviolet excitation were imaged using a visible near-infrared (VNIR) hyperspectral camera. The imaged kernels were chemically analyzed to provide reference information for image analysis. This paper describes a procedure to process corn kernels located in different images for statistical training and classification. Two classification algorithms, Maximum Likelihood and Binary Encoding, were used to classify each corn kernel into "control" or "contaminated" through pixel classification. The Binary Encoding approach had a slightly better performance with accuracy equals to 87% or 88% when 20 ppb or 100 ppb was used as classification threshold, respectively.

  8. Aflatoxin detection in whole corn kernels using hyperspectral methods

    NASA Astrophysics Data System (ADS)

    Casasent, David; Chen, Xue-Wen

    2004-03-01

    Hyperspectral (HS) data for the inspection of whole corn kernels for aflatoxin is considered. The high-dimensionality of HS data requires feature extraction or selection for good classifier generalization. For fast and inexpensive data collection, only several features (λ responses) can be used. These are obtained by feature selection from the full HS response. A new high dimensionality branch and bound (HDBB) feature selection algorithm is used; it is found to be optimum, fast and very efficient. Initial results indicate that HS data is very promising for aflatoxin detection in whole kernel corn.

  9. Zearalenone, deoxynivalenol and aflatoxin B1 and their metabolites in pig urine as biomarkers for mycotoxin exposure.

    PubMed

    Thieu, N Q; Pettersson, H

    2009-06-01

    Methods to determine zearalenone (ZEA), deoxynivalenol (DON), aflatoxins (AF) and their metabolites in pig urine were developed as biomarkers for pig exposure to the mycotoxins in feed. Urine samples were incubated with β-glucuronidase to cleave conjugates, extracted and cleaned-up with solid phase and immunoaffinity columns, followed by HPLC with UV and fluorescence detection. Good recoveries (83-130%), low variation (2-10%), and low detection limits (0.3-9.9 ng/ml) were obtained. The results of controlled AFB1 feeding trials found no difference in urine concentrations of AFB1 or AFM1 from pigs fed three different levels (127, 227, 327 µg/kg) of AFB1 in diets. The excretion of AFB1 and AFM1 in urine was on average 30% of the oral dose and the ratio AFB1 to AFM1 was around 23%. The analysis of 15 Vietnamese pig urine samples indicate a relatively high exposure of ZEA, DON and AF, which were found as toxin or metabolites in 47, 73, and 80% of the urine samples, respectively.

  10. BIOSYNTHESIS OF YEAST CAROTENOIDS

    PubMed Central

    Simpson, Kenneth L.; Nakayama, T. O. M.; Chichester, C. O.

    1964-01-01

    Simpson, Kenneth L. (University of California, Davis), T. O. M. Nakayama, and C. O. Chichester. Biosynthesis of yeast carotenoids. J. Bacteriol. 88:1688–1694. 1964.—The biosynthesis of carotenoids was followed in Rhodotorula glutinis and in a new strain, 62-506. The treatment of the growing cultures by methylheptenone, or ionone, vapors permitted observations of the intermediates in the biosynthetic pathway. On the basis of concentration changes and accumulation in blocked pathways, the sequence of carotenoid formation is postulated as phytoene, phytofluene, ζ-carotene, neurosporene, β-zeacarotene, γ-carotene, torulin, a C40 aldehyde, and torularhodin. Torulin and torularhodin were established as the main carotenoids of 62-506. PMID:14240958

  11. Histidine biosynthesis in plants.

    PubMed

    Stepansky, A; Leustek, T

    2006-03-01

    The study of histidine metabolism has never been at the forefront of interest in plant systems despite the significant role that the analysis of this pathway has played in development of the field of molecular genetics in microbes. With the advent of methods to analyze plant gene function by complementation of microbial auxotrophic mutants and the complete analysis of plant genome sequences, strides have been made in deciphering the histidine pathway in plants. The studies point to a complex evolutionary origin of genes for histidine biosynthesis. Gene regulation studies have indicated novel regulatory networks involving histidine. In addition, physiological studies have indicated novel functions for histidine in plants as chelators and transporters of metal ions. Recent investigations have revealed intriguing connections of histidine in plant reproduction. The exciting new information suggests that the study of plant histidine biosynthesis has finally begun to flower.

  12. Biosynthesis of Hemes.

    PubMed

    Beale, Samuel I

    2007-04-01

    This review is concerned specifically with the structures and biosynthesis of hemes in E. coli and serovar Typhimurium. However, inasmuch as all tetrapyrroles share a common biosynthetic pathway, much of the material covered here is applicable to tetrapyrrole biosynthesis in other organisms. Conversely, much of the available information about tetrapyrrole biosynthesis has been gained from studies of other organisms, such as plants, algae, cyanobacteria, and anoxygenic phototrophs, which synthesize large quantities of these compounds. This information is applicable to E. coli and serovar Typhimurium. Hemes play important roles as enzyme prosthetic groups in mineral nutrition, redox metabolism, and gas-and redox-modulated signal transduction. The biosynthetic steps from the earliest universal precursor, 5-aminolevulinic acid (ALA), to protoporphyrin IX-based hemes constitute the major, common portion of the pathway, and other steps leading to specific groups of products can be considered branches off the main axis. Porphobilinogen (PBG) synthase (PBGS; also known as ALA dehydratase) catalyzes the asymmetric condensation of two ALA molecules to form PBG, with the release of two molecules of H2O. Protoporphyrinogen IX oxidase (PPX) catalyzes the removal of six electrons from the tetrapyrrole macrocycle to form protoporphyrin IX in the last biosynthetic step that is common to hemes and chlorophylls. Several lines of evidence converge to support a regulatory model in which the cellular level of available or free protoheme controls the rate of heme synthesis at the level of the first step unique to heme synthesis, the formation of GSA by the action of GTR.

  13. Genome-wide transcriptome analysis of cotton (Gossypium hirsutum L.) identifies candidate gene signatures in response to aflatoxin producing fungus Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are toxic metabolites and potent carcinogen produced from asexual fungi Aspergillus flavus and A. parasiticus. Aflatoxins can contaminate cottonseed under conducive preharvest and postharvest conditions. U.S. federal regulations restrict the use of aflatoxin contaminated cottonseed at >20...

  14. Aflatoxin metabolism in humans: detection of metabolites and nucleic acid adducts in urine by affinity chromatography

    SciTech Connect

    Groopman, J.D.; Donahue, P.R.; Zhu, J.Q.; Chen, J.S.; Wogan, G.N.

    1985-10-01

    A high-affinity IgM monoclonal antibody specific for aflatoxins was covalently bound to Sepharose 4B and used as a preparative column to isolate aflatoxin derivatives from the urine of people and experimental animals who had been exposed to the carcinogen environmentally or under laboratory conditions. Aflatoxin levels were quantified by radioimmunoassay and high-performance liquid chromatography after elution from the affinity column. In studies on rats injected with ( UC)aflatoxin B1, the authors identified the major aflatoxin-DNA adduct, 2,3-dihydro-2-(N7-guanyl)-3-hydroxy-aflatoxin B1 (AFB1-N7-Gua), and the oxidative metabolites M1 and P1 as the major aflatoxin species present in the urine. When this methodology was applied to human urine samples obtained from people from the Guangxi Province of China exposed to aflatoxin B1 through dietary contamination, the aflatoxin metabolites detected were also AFB1-N7-Gua and aflatoxins M1 and P1. Therefore, affinity chromatography using a monoclonal antibody represents a useful and rapid technique with which to isolate this carcinogen and its metabolites in biochemical epidemiology and for subsequent quantitative measurements, providing exposure information that can be used for risk assessment.

  15. Aflatoxin regulations and global pistachio trade: insights from social network analysis.

    PubMed

    Bui-Klimke, Travis R; Guclu, Hasan; Kensler, Thomas W; Yuan, Jian-Min; Wu, Felicia

    2014-01-01

    Aflatoxins, carcinogenic toxins produced by Aspergillus fungi, contaminate maize, peanuts, and tree nuts in many regions of the world. Pistachios are the main source of human dietary aflatoxins from tree nuts worldwide. Over 120 countries have regulations for maximum allowable aflatoxin levels in food commodities. We developed social network models to analyze the association between nations' aflatoxin regulations and global trade patterns of pistachios from 1996-2010. The main pistachio producing countries are Iran and the United States (US), which together contribute to nearly 75% of the total global pistachio market. Over this time period, during which many nations developed or changed their aflatoxin regulations in pistachios, global pistachio trade patterns changed; with the US increasingly exporting to countries with stricter aflatoxin standards. The US pistachio crop has had consistently lower levels of aflatoxin than the Iranian crop over this same time period. As similar trading patterns have also been documented in maize, public health may be affected if countries without aflatoxin regulations, or with more relaxed regulations, continually import crops with higher aflatoxin contamination. Unlike the previous studies on maize, this analysis includes a dynamic element, examining how trade patterns change over time with introduction or adjustment of aflatoxin regulations.

  16. Correlation of aflatoxin contamination with zinc content of chicken feed

    SciTech Connect

    Jones, F.T.; Hagler, W.M. Jr.; Hamilton, P.B.

    1984-03-01

    Feed samples from chicken houses in five commercial chicken operations were analyzed for Zn, Mn, Fe, Cu, Cd, and aflatoxin content. Mean aflatoxin content of these samples was 14 ppb (14 ng/g) as opposed to 1.2 ppb in samples taken when the feed was made. Aflatoxin content of the feed samples correlated significantly with Zn content but not with Mn, Fe, or Cu, all of which correlated significantly with Zn. Zn content of unamended feed (<20 ppm (20 ..mu..g/g) is normally supplemented with a mineral premix containing Zn, Mn, Fe, and Cu to meet the nutrient requirements of chickens (40 ppm of Zn). The mean zinc concentration of the feed samples (117 ppm) was about threefold greater than the nutrient requirement and ranged from 58 to 162 ppm in individual samples. These field survey results parallel earlier reports of augmented production of aflatoxin in monocultures of aflatoxigenic fungi in corn and other ingredients supplemented with Zn. These results suggest that stricter control of Zn levels during manufacture could reduce aflatoxing contamination of feed consumed by chickens.

  17. Aflatoxins ingestion and canine mammary tumors: There is an association?

    PubMed

    Frehse, M S; Martins, M I M; Ono, E Y S; Bracarense, A P F R L; Bissoqui, L Y; Teixeira, E M K; Santos, N J R; Freire, R L

    2015-10-01

    The aim of this study was to determine the presence of mycotoxins on dogs feed and to explore the potential association between mycotoxins exposure and the chance of mamary tumors in a case-control study. The study included 256 female dogs from a hospital population, 85 with mammary tumors (case group) and 171 without mammary tumors (control group). An epidemiological questionnaire was applied to both groups, and the data were analyzed by the EpiInfo statistical package. For the study, 168 samples of the feed offered to dogs were analyzed for the presence of aflatoxins, fumonisins and zearalenone by high-performance liquid chromatography. Mycotoxins were found in 79 samples (100%) in the case group and 87/89 (97.8%) in the control group. Mycotoxins were detected in all types of feed, regardless feed quality. Level of aflatoxin B1 (p = 0.0356, OR = 2.74, 95%, CI 1.13 to 6.60), aflatoxin G1 (AFG1) (p = 0.00007, OR = 4.60, 95%, CI = 2.16 to 9.79), and aflatoxin G2 (AFG2) (p = 0.0133, OR = 9.91, 95%, CI 1.21 to 81.15) were statistically higher in case of mammary cancer. In contrast, neutering was a protective factor for mammary cancer (p = 0.0004, OR = 0.32, 95%, CI = 0.17 to 0.60).

  18. Use of Probiotics to Control Aflatoxin Production in Peanut Grains

    PubMed Central

    da Silva, Juliana Fonseca Moreira; Peluzio, Joenes Mucci; Prado, Guilherme; Madeira, Jovita Eugênia Gazzinelli Cruz; Silva, Marize Oliveira; de Morais, Paula Benevides; Rosa, Carlos Augusto; Pimenta, Raphael Sanzio; Nicoli, Jacques Robert

    2015-01-01

    Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20) were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1%) followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.). All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains. PMID:26221629

  19. RNAi control of aflatoxins in peanut plants, a multifactorial system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RNA-interference (RNAi)-mediated control of aflatoxin contamination in peanut plants is a multifactorial and hyper variable system. The use of RNAi biotechnology to silence single genes in plants has inherently high-variability among transgenic events. Also the level of expression of small interfe...

  20. Aflatoxin resistance in maize: what have we learned lately?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination of maize grain is a huge economic and health problem, causing death and increased disease burden in much of the developing world and income loss in the developed world. Despite the gravity of the problem, deployable solutions are still being sought. In the past 15 years, much...

  1. 7 CFR 983.5 - Aflatoxin inspection certificate.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Aflatoxin inspection certificate. 983.5 Section 983.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  2. 7 CFR 983.5 - Aflatoxin inspection certificate.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Aflatoxin inspection certificate. 983.5 Section 983.5 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN...

  3. Use of Probiotics to Control Aflatoxin Production in Peanut Grains.

    PubMed

    da Silva, Juliana Fonseca Moreira; Peluzio, Joenes Mucci; Prado, Guilherme; Madeira, Jovita Eugênia Gazzinelli Cruz; Silva, Marize Oliveira; de Morais, Paula Benevides; Rosa, Carlos Augusto; Pimenta, Raphael Sanzio; Nicoli, Jacques Robert

    2015-01-01

    Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20) were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1%) followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.). All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains.

  4. Molecular markers and strategies to control aflatoxin in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methods of isolation of molecular markers and software developed in ARS for finding the most informative markers will be presented. Also, two different approaches being used at the NPRL to reduce aflatoxin in peanut will be discussed. One is the development of phytoalexin-detoxification enzyme inh...

  5. Single corn kernel aflatoxin B1 extraction and analysis method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are highly carcinogenic compounds produced by the fungus Aspergillus flavus. Aspergillus flavus is a phytopathogenic fungus that commonly infects crops such as cotton, peanuts, and maize. The goal was to design an effective sample preparation method and analysis for the extraction of afla...

  6. Extracts of Agave americana inhibit aflatoxin production in Aspergillus parasiticus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxigenic fungi invade crops prior to harvest as well as during storage and produce harmful, even carcinogenic toxins such as aflatoxins. Since consumers demand safe commodities, and due to enhanced public awareness of the dangers of many synthetic fungicides, the importance of investigating alterna...

  7. Use of isotope-labeled aflatoxins for LC-MS/MS stable isotope dilution analysis of foods.

    PubMed

    Cervino, Christian; Asam, Stefan; Knopp, Dietmar; Rychlik, Michael; Niessner, Reinhard

    2008-03-26

    Aflatoxins are a group of very carcinogenic mycotoxins that can be found on a wide range of food commodities including nuts, cereals, and spices. In this study, the first LC-MS/MS stable isotope dilution assay (SIDA) for the determination of aflatoxins in foods was developed. The development of this method was enabled by easily accessible isotope-labeled (deuterated) aflatoxins B2 and G2, which were synthesized by catalytic deuteration of aflatoxin B1 and G1, purified, and well-characterized by NMR and MS. All four aflatoxins of interest (B1, B2, G1, and G2) were quantified in food samples by using these two labeled internal standards. The response factors (RF) of the linear calibrations were revealed to be matrix independent for labeled aflatoxin B2/aflatoxin B2 and labeled aflatoxin G2/aflatoxin G2. For labeled aflatoxin B 2/aflatoxin B 1 and labeled aflatoxin B2/aflatoxin G1 matrix-matched calibration was performed for the model matrices almonds and wheat flour, showing significant differences of the RFs. Limits of detection (LOD) were determined by applying a statistical approach in the presence of the two model matrices, yielding 0.31 microg/kg (aflatoxin B1), 0.09 microg/kg (aflatoxin B2), 0.38 microg/kg (aflatoxin G1), and 0.32 microg/kg (aflatoxin G2) for almonds (similar LODs were obtained for wheat flour). Recovery rates were between 90 and 105% for all analytes. Coefficients of variation (CV) of 12% (aflatoxin B1), 3.6% (aflatoxin B2), 14% (aflatoxin G1), and 4.8% (aflatoxin G2) were obtained from interassay studies. For further validation, a NIST standard reference food sample was analyzed for aflatoxins B1 and B2. The method was successfully applied to determine trace levels of aflatoxins in diverse food matrices such as peanuts, nuts, grains, and spices. Aflatoxin contents in these samples ranged from about 0.5 to 6 microg/kg.

  8. Analysis of cocoa products for ochratoxin A and aflatoxins.

    PubMed

    Turcotte, Anne-Marie; Scott, Peter M; Tague, Brett

    2013-08-01

    Eighty-five samples of cocoa products sampled in Canada were analysed for ochratoxin A (OTA) and aflatoxins in 2011-2012. Inclusion of the aflatoxins in this survey required additional method development. Chocolate was extracted with methanol-water plus NaCl, while for cocoa two successive extractions with methanol and methanol-water were made. Extracts were cleaned on an AflaOchra immunoaffinity column (IAC). Determination was by reversed phase high performance liquid chromatography (HPLC). Detection of the aflatoxins was with a post-column photochemical reactor and of OTA by fluorescence detection. Mean limits of quantification (LOQ) of chocolate and cocoa powders were 0.16 ng/g (OTA) and 0.07 ng/g (aflatoxin B1), respectively. Survey results showed that the incidences of OTA above the LOQ in natural cocoa were 15/15 (mean 1.17 ng/g), 20/21 for alkalized cocoa (mean 1.06 ng/g), 9/9 for baking chocolate (mean 0.49 ng/g), 20/20 for dark chocolate (mean 0.39 ng/g), 7/10 for milk chocolate (mean 0.19 ng/g), 5/5 for cocoa liquor (mean 0.43 ng/g), and 0/5 for cocoa butter. These results confirm our previous work with OTA. In the same samples, incidences of aflatoxin B1 above the LOQ were 14/15 for natural cocoa (mean 0.86 ng/g), 20/21 for alkalized cocoa (mean 0.37 ng/g), 7/9 for baking chocolate (mean 0.22 ng/g), 16/20 for dark chocolate (mean 0.19 ng/g), 7/10 for milk chocolate (mean 0.09 ng/g), 4/5 for cocoa liquor (mean 0.43 ng/g), and 0/5 for cocoa butter. Both aflatoxins and OTA were confirmed by HPLC-MS/MS when OTA or aflatoxin levels found were above 2 ng/g in cocoa.

  9. Aflatoxin, Aspergillus, Maize, and the Relevance to Alternative Fuels (or Aflatoxin: What is It, Can We Get Rid of It, and Should the Ethanol Industry Care?)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contamination of agricultural commodities by Aspergillus flavus and its subsequent production of aflatoxin is a well known problem. The resulting aflatoxin contamination if undetected results in fatal health issues for both man and animals. To prevent these effects regulatory limits on aflatox...

  10. Chirality and protein biosynthesis.

    PubMed

    Banik, Sindrila Dutta; Nandi, Nilashis

    2013-01-01

    Chirality is present at all levels of structural hierarchy of protein and plays a significant role in protein biosynthesis. The macromolecules involved in protein biosynthesis such as aminoacyl tRNA synthetase and ribosome have chiral subunits. Despite the omnipresence of chirality in the biosynthetic pathway, its origin, role in current pathway, and importance is far from understood. In this review we first present an introduction to biochirality and its relevance to protein biosynthesis. Major propositions about the prebiotic origin of biomolecules are presented with particular reference to proteins and nucleic acids. The problem of the origin of homochirality is unresolved at present. The chiral discrimination by enzymes involved in protein synthesis is essential for keeping the life process going. However, questions remained pertaining to the mechanism of chiral discrimination and concomitant retention of biochirality. We discuss the experimental evidence which shows that it is virtually impossible to incorporate D-amino acids in protein structures in present biosynthetic pathways via any of the two major steps of protein synthesis, namely aminoacylation and peptide bond formation reactions. Molecular level explanations of the stringent chiral specificity in each step are extended based on computational analysis. A detailed account of the current state of understanding of the mechanism of chiral discrimination during aminoacylation in the active site of aminoacyl tRNA synthetase and peptide bond formation in ribosomal peptidyl transferase center is presented. Finally, it is pointed out that the understanding of the mechanism of retention of enantiopurity has implications in developing novel enzyme mimetic systems and biocatalysts and might be useful in chiral drug design.

  11. The Use of Feed Additives to Reduce the Effects of Aflatoxin and Deoxynivalenol on Pig Growth, Organ Health and Immune Status during Chronic Exposure

    PubMed Central

    Weaver, Alexandra C.; See, M. Todd; Hansen, Jeff A.; Kim, Yong B.; De Souza, Anna L. P.; Middleton, Tina F.; Kim, Sung Woo

    2013-01-01

    Three feed additives were tested to improve the growth and health of pigs chronically challenged with aflatoxin (AF) and deoxynivalenol (DON). Gilts (n = 225, 8.8 ± 0.4 kg) were allotted to five treatments: CON (uncontaminated control); MT (contaminated with 150 µg/kg AF and 1100 µg/kg DON); A (MT + a clay additive); B (MT + a clay and dried yeast additive); and C (MT + a clay and yeast culture additive). Average daily gain (ADG) and feed intake (ADFI) were recorded for 42 days, blood collected for immune analysis and tissue samples to measure damage. Feeding mycotoxins tended to decrease ADG and altered the immune system through a tendency to increase monocytes and immunoglobulins. Mycotoxins caused tissue damage in the form of liver bile ductule hyperplasia and karyomegaly. The additives in diets A and B reduced mycotoxin effects on the immune system and the liver and showed some ability to improve growth. The diet C additive played a role in reducing liver damage. Collectively, we conclude that AF and DON can be harmful to the growth and health of pigs consuming mycotoxins chronically. The selected feed additives improved pig health and may play a role in pig growth. PMID:23867763

  12. STBC AF relay for unmanned aircraft system

    NASA Astrophysics Data System (ADS)

    Adachi, Fumiyuki; Miyazaki, Hiroyuki; Endo, Chikara

    2015-01-01

    If a large scale disaster similar to the Great East Japan Earthquake 2011 happens, some areas may be isolated from the communications network. Recently, unmanned aircraft system (UAS) based wireless relay communication has been attracting much attention since it is able to quickly re-establish the connection between isolated areas and the network. However, the channel between ground station (GS) and unmanned aircraft (UA) is unreliable due to UA's swing motion and as consequence, the relay communication quality degrades. In this paper, we introduce space-time block coded (STBC) amplify-and-forward (AF) relay for UAS based wireless relay communication to improve relay communication quality. A group of UAs forms single frequency network (SFN) to perform STBC-AF cooperative relay. In STBC-AF relay, only conjugate operation, block exchange and amplifying are required at UAs. Therefore, STBC-AF relay improves the relay communication quality while alleviating the complexity problem at UAs. It is shown by computer simulation that STBC-AF relay can achieve better throughput performance than conventional AF relay.

  13. Modulation of macrophage activity by aflatoxins B1 and B2 and their metabolites aflatoxins M1 and M2.

    PubMed

    Bianco, G; Russo, R; Marzocco, S; Velotto, S; Autore, G; Severino, L

    2012-05-01

    Aflatoxins are natural contaminants frequently found both in food and feed. Many of them exert immunomodulatory properties in mammals; therefore, the aim of the current study was to investigate immune-effects of AFB1, AFB2, AFM1 and AFM2, alone and differently combined, in J774A.1 murine macrophages. MTT assay showed that AFB1, alone and combined with AFB2, possess antiproliferative activity only at the highest concentration; such effect was not shown by their hydroxylated metabolites, AFM1 and AFM2, respectively. However, the immunotoxic effects of the aflatoxins evaluated in the current study may be due to the inhibition of production of active oxygen metabolites such as NO. Cytofluorimetric assay in macrophages exposed to aflatoxins (10-100 μM) revealed that their cytoxicity is not related to apoptotic pathways. Nevertheless, a significant increase of the S phase cell population accompanied by a decrease in G0/G1 phase cell population was observed after AFB1 treatment. In conclusion, the results of the current study suggest that aflatoxins could compromise the macrophages functions; in particular, co-exposure to AFB1, AFB2, AFM1 and AFM2 may exert interactions which can significantly affect immunoreactivity.

  14. Identification of resistance to aflatoxin accumulation and yield potential in maize hybrids in the Southeast Regional Aflatoxin Trials (SERAT)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins pose a serious health hazard to humans and livestock, requiring significant economic cost in identifying and disposing of contaminated grain. Since 2003, a multi-environmental trial of public breeding maize (Zea mays L.) hybrids across multiple programs in the southeastern United States h...

  15. Behavior of sup 14 C aflatoxin M1 during camembert cheese making

    SciTech Connect

    Fremy, J.M.; Roiland, J.C.; Gaymard, A. )

    1990-05-01

    Camembert cheeses are made from raw milk spiked with aflatoxin M1. Three aflatoxin M1 levels (7.5 micrograms/L, 3 micrograms/L, and 0.3 micrograms/L) are used. In curds 35.6, 47.1, and 57.7% of aflatoxin M1, respectively, are recovered, and in wheys 64.4, 52.9, and 42.3%, respectively, are recovered. During the first 15 days of storage, the aflatoxin M1 content of different cheeses decreases 25, 55, and 75%, respectively. A similar experiment is made with milk contaminated with {sup 14}C labeled aflatoxin M1. The same results are obtained, except for the behavior of aflatoxin M1 in cheese; the same 14C activity is recovered during storage for 30 days.

  16. Fractionation of radioactivity in the milk of goats administered UC-aflatoxin B1

    SciTech Connect

    Goto, T.; Hsieh, D.P.

    1985-05-01

    A detailed fractionation of radioactivity in the milk of goats administered UC-aflatoxin B1 at low doses was performed. The milk collected in the first 24 h following dosing contained radioactivity equivalent to 0.45-1.1% of the dose given. The radioactivity in each sample was partitioned into 4 fractions: ether, protein, dichloromethane, and water-alcohol. Over 80% of the radioactivity was detected in the dichloromethane fraction, of which over 95% was attributable to aflatoxin M1. No aflatoxin B1 or other known aflatoxin metabolites were detected in any fraction. The results indicate that the major metabolite of aflatoxin B1 in goat milk is aflatoxin M1 and that other metabolites, including conjugates, are of minor significance.

  17. Quantitative Determination of Aflatoxin by High Performance Liquid Chromatography in Wheat Silos in Golestan Province, North of Iran

    PubMed Central

    NAMJOO, Mohadeseh; SALAMAT, Faezeh; RAJABLI, Niloofar; HAJIHOSEEINI, Reza; NIKNEJAD, Farhad; KOHSAR, Faramarz; JOSHAGHANI, Hamidreza

    2016-01-01

    Background: Aflatoxins are the most common mycotoxins that contaminate crops. They are produced by fungi such as Aspergillus flavus and Aspergillus parasiticus. Wheat (Tricitumaestivum) is one of the most important staple foods used in Iran, and the environmental conditions in the north of Iran are favorable to fungal growth. This study was designed in order to determine the aflatoxin concentration in wheat samples from silos in Golestan Province north of Iran. Methods: Samples were collected from three silos of Golestan province. First, aflatoxins were isolated using immunoaffinity chromatography. Then the aflatoxin concentrations were determined by High performance liquid chromatography (HPLC) method and fluorescence detector. Results: Ten out of 34 samples (29.4% of samples) were contaminated by aflatoxins.No concentration was found above permitted aflatoxin levels in Iran (15 ng/g). In one sample (2.9%), aflatoxin B1 was seen over the permissible limits in Iran. The highest level found in samples for total aflatoxin, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 were 7.08 ng/g, 6.91 ng/g, 0.29 ng/g, 1.37 ng/g and 0.23 ng/g, respectively. No correlation was found between humidity levels in wheat samples contained aflatoxin and wheat samples without aflatoxin. Conclusion: Despite the total aflatoxins determined in samples were below the permissible limits in Iran, the 29% aflatoxin contamination rate can negatively affect health factors and it should not be neglected. So, it is predictable that if the storage duration of samples increases, the aflatoxin contamination levels will increase. PMID:27516997

  18. Functional Genomic Analysis of Aspergillus flavus Interacting with Resistant and Susceptible Peanut

    PubMed Central

    Wang, Houmiao; Lei, Yong; Yan, Liying; Wan, Liyun; Ren, Xiaoping; Chen, Silong; Dai, Xiaofeng; Guo, Wei; Jiang, Huifang; Liao, Boshou

    2016-01-01

    In the Aspergillus flavus (A. flavus)–peanut pathosystem, development and metabolism of the fungus directly influence aflatoxin contamination. To comprehensively understand the molecular mechanism of A. flavus interaction with peanut, RNA-seq was used for global transcriptome profiling of A. flavus during interaction with resistant and susceptible peanut genotypes. In total, 67.46 Gb of high-quality bases were generated for A. flavus-resistant (af_R) and -susceptible peanut (af_S) at one (T1), three (T2) and seven (T3) days post-inoculation. The uniquely mapped reads to A. flavus reference genome in the libraries of af_R and af_S at T2 and T3 were subjected to further analysis, with more than 72% of all obtained genes expressed in the eight libraries. Comparison of expression levels both af_R vs. af_S and T2 vs. T3 uncovered 1926 differentially expressed genes (DEGs). DEGs associated with mycelial growth, conidial development and aflatoxin biosynthesis were up-regulated in af_S compared with af_R, implying that A. flavus mycelia more easily penetrate and produce much more aflatoxin in susceptible than in resistant peanut. Our results serve as a foundation for understanding the molecular mechanisms of aflatoxin production differences between A. flavus-R and -S peanut, and offer new clues to manage aflatoxin contamination in crops. PMID:26891328

  19. Efficacy of adsorbents (bentonite and diatomaceous earth) and turmeric (Curcuma longa) in alleviating the toxic effects of aflatoxin in chicks.

    PubMed

    Dos Anjos, F R; Ledoux, D R; Rottinghaus, G E; Chimonyo, M

    2015-01-01

    A study was conducted to determine the efficacy of bentonite clay (BC), diatomaceous earth (DE) and turmeric powder (TUM) in alleviating the toxic effects of aflatoxin B1 (AFB1). A total of 250 Ross-308 d-old male broiler chicks were assigned to 10 dietary treatments (5 replicates of 5 chicks) from hatch to d 21. Dietary treatments were: basal diet; basal diet plus AFB1 (2 mg) or BC (0.75%), or DE (0.75%), or TUM (200 mg/kg curcuminoids) and different combinations of AFB1, BC, DE and TUM. Feed intake (FI), body weight gain (BWG) and feed gain (FG) of the birds fed on BC or DE separately were not different from control birds. Birds fed on TUM only had similar FI and FG but lower BWG than control chicks. Aflatoxin B1 reduced FI, BWG and serum concentrations of glucose, albumin, total protein calcium, but increased FG and relative liver and kidney weights. Chicks fed on the combination of AFB1 and BC had similar FI and FG to control chicks. Chicks fed on the combination of DE and AFB1 had lower FI (23.1%) and BWG (28.6%) compared with control chicks. Chicks fed on the combination of TUM and AFB1 also had decreased FI (26.2 %) and BWG (31%) compared with control chicks. Chicks fed on the combination of AFB1, BC and TUM consumed significantly higher amounts of feed compared with chicks fed on only AF, but gained less when compared with control diet chicks. Chicks fed on the combination of AFB1, DE and TUM diet had poorer growth performance than those fed on AFB1 alone. None of the combination diets reduced the severity of liver lesions.

  20. Short communication: investigation of aflatoxin M1 levels in infant follow-on milks and infant formulas sold in the markets of Ankara, Turkey.

    PubMed

    Er, B; Demirhan, B; Yentür, G

    2014-01-01

    Aflatoxins are fungal toxins known to be carcinogenic and are classified as food contaminants. This study was performed to investigate aflatoxin (AF) M1 levels in baby foods sold in Ankara (Turkey) and to evaluate the obtained results according to the Turkish Food Codex (TFC). For this purpose, a total of 84 baby food samples (50 follow-on milks and 34 infant formulas) were obtained from different markets in Ankara and the presence of AFM1 in the samples was analyzed by ELISA. In 32 (38.1%) of 84 infant food samples, the presence of AFM1 was detected in concentrations ranging between 0.0055 and 0.0201 µg/kg. The mean level (± standard error) of AFM1 was found to be 0.0089 ± 0.0006 µg/kg in positive infant follow-on milks. Aflatoxin M1 was detected in only 1 infant formula sample (2.94%) at a concentration of 0.0061 µg/kg. The extrapolated levels of AFB1 contamination in feedstuffs were calculated based on levels of AFM1 in baby food samples. The data estimating AFB1 contamination in dairy cattle feedstuff indicate that contamination may range from 0.3410 to 1.2580 µg/kg, with the mean level (± standard error) being 0.5499 ± 0.0385 µg/kg, which is lower than the level set by the TFC and European Union regulations (5 µg/kg). According to the obtained results, the levels of AFM1 in analyzed samples were within the allowed limit (0.025 µg/kg) set in the TFC. Low levels of AFM1 in infant follow-on milks and infant formula samples obtained during the study do not pose a health risk to infants.

  1. [Determination of aflatoxin B1, B2, G1, G2 in armeniacae semen amarum by high-performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Zheng, Run-Sheng; Xu, Hui; Wang, Wen-Li; Zhan, Ruo-Ting; Chen, Wei-Wen

    2013-10-01

    A simple, rapid and cost-effective high-performance liquid chromatography-tandem mass spectrometry (LC-MS/ MS) method was established for simultaneous determination of aflatoxins (AFB1, AFB2, AFG1, AFG2) in Armeniacae Semen Amarum and the application was performance in 11 samples collected from different markets, medical stores and hospitals. The sample was extracted with 84% acetonitrile/water and 250 microL extraction was directly injected into a LC-MS/MS system without further purification procedure after being redissolved with methanol. The LC separation was performed on a C18 column with a linear gradient elution program of 4 mmol x L(-1) NH4 Ac-0.1% formic acid solution and menthol as the mobile phase. Selected reaction monitoring (SRM) was used for selective determination of the four aflatoxins on a triple quadruple mass spectrometer, which was operated in positive ionization modes. All the four aflatoxins showed a good linear relationship with r > 0.999 0, the average recoveries were between 87.88% and 102.9% and the matrix effect was ranged from 90.71% to 99.30% in low, intermediate and high levels. Furthermore, the higher recovery was obtained by the method reported in this study, comparing to the cleanup procedure with the Mycosep 226 purification column. Eleven samples collected were detected and the contamination levels of the AFB1 were between 1.590-2.340 microg x kg(-1) and the AF (B1 + B2 + G1 + G2) was ranged from 2.340 to 3.340 microg x kg(-1). In summary, the developed method was suitable to detect and screen AFB1, AFB2, AFG1, AFG2 in Armeniacae Semen Amarum.

  2. Automated Aflatoxin Analysis Using Inline Reusable Immunoaffinity Column Cleanup and LC-Fluorescence Detection.

    PubMed

    Rhemrev, Ria; Pazdanska, Monika; Marley, Elaine; Biselli, Scarlett; Staiger, Simone

    2015-01-01

    A novel reusable immunoaffinity cartridge containing monoclonal antibodies to aflatoxins coupled to a pressure resistant polymer has been developed. The cartridge is used in conjunction with a handling system inline to LC with fluorescence detection to provide fully automated aflatoxin analysis for routine monitoring of a variety of food matrixes. The handling system selects an immunoaffinity cartridge from a tray and automatically applies the sample extract. The cartridge is washed, then aflatoxins B1, B2, G1, and G2 are eluted and transferred inline to the LC system for quantitative analysis using fluorescence detection with postcolumn derivatization using a KOBRA® cell. Each immunoaffinity cartridge can be used up to 15 times without loss in performance, offering increased sample throughput and reduced costs compared to conventional manual sample preparation and cleanup. The system was validated in two independent laboratories using samples of peanuts and maize spiked at 2, 8, and 40 μg/kg total aflatoxins, and paprika, nutmeg, and dried figs spiked at 5, 20, and 100 μg/kg total aflatoxins. Recoveries exceeded 80% for both aflatoxin B1 and total aflatoxins. The between-day repeatability ranged from 2.1 to 9.6% for aflatoxin B1 for the six levels and five matrixes. Satisfactory Z-scores were obtained with this automated system when used for participation in proficiency testing (FAPAS®) for samples of chilli powder and hazelnut paste containing aflatoxins.

  3. Aflatoxin contamination in foods and foodstuffs in Tokyo: 1986-1990.

    PubMed

    Tabata, S; Kamimura, H; Ibe, A; Hashimoto, H; Iida, M; Tamura, Y; Nishima, T

    1993-01-01

    Aflatoxins were determined in 3054 samples of foods or foodstuffs, including cereals, nuts, beans, spices, dairy products, dry fruits, and edible oil. Samples were collected in Tokyo from 1986 to 1990. Aflatoxins were found in rice products, adlay, corn, crude sugar, peanut products, pistachio nuts, brazil nuts, sesame products, butter beans, white pepper, red pepper, paprika, nutmeg, and mixed spices. The highest incidence of aflatoxin contamination was observed in nutmeg (80%), and the highest level of aflatoxin B1 was observed in pistachio nuts (1382 ppb).

  4. Effect of aluminosilicates and bentonite on aflatoxin-induced developmental toxicity in rat.

    PubMed

    Abdel-Wahhab, M A; Nada, S A; Amra, H A

    1999-01-01

    Numerous studies have established that aflatoxin is a potent developmental toxin in animals. Previous research has demonstrated that a phyllosilicate clay, hydrated sodium calcium aluminosilicate (HSCAS or Novasil), tightly binds and immobilizes aflatoxins in the gastrointestinal tract of animals and markedly reduces the bioavailability and toxicity of aflatoxin. Our objective in this study was to utilize the pregnant rat as an in vivo model to compare the potential of HSCAS and bentonite to prevent the developmental toxicity of aflatoxin. Aluminosilicates (HSCAS) and bentonite were added to the diet at a level of 0.5% (w/w) and fed to the pregnant rat throughout pregnancy (i.e. days 0-20). Test animals were fed an aflatoxin-contaminated diet (2.5 mg kg(-1) diet) with or without sorbents during gestation days 6-15. Evaluations of toxicity were performed on day 20. These included maternal (mortality, body weights, feed intake and litter weights), developmental (embryonic resorptions and fetal body weights) and biochemical (ALT, AST and AP) evaluations. Sorbents alone were not toxic and aflatoxin alone resulted in significant maternal and developmental toxicity. Animals treated with phyllosilicate (plus aflatoxin) were comparable to controls following evaluations for resorptions, live fetuses and fetal body weights, as well as biochemical parameters. While bentonite plus aflatoxin resulted in significant reduction in fetal body weight, none of the fetuses from HSCAS or bentonite plus aflatoxin-treated groups had any gross, internal soft tissue or major skeletal malformations.

  5. Dietary Factors and Hepatoma in Rainbow Trout (Salmo gairdneri). I. Aflatoxins in Vegetable Protein Feedstuffs

    USGS Publications Warehouse

    Sinnhuber, R.O.; Wales, J.H.; Ayers, J.L.; Engebrecht, R.H.; Amend, D.F.

    1968-01-01

    Aflatoxins (toxic metabolites of the mold Aspergillus flavus) were present in a commercial trout ration causing hepatoma in rainbow trout. Cottonseed meal and solvent extracts of cottonseed meal and of rations containing cottonseed meal and peanut meal were found by chemical assay and confirmed by duckling assay to contain aflatoxins. Diets containing these materials and a purified test diet to which aflatoxins had been added produced microscopic tumors in 6 months and gross lesions of hepatocarcinoma in 9 months. Similar diets without aflatoxin were negative.

  6. Effects of various acids and salts on growth and aflatoxin production by Aspergillus flavus NRRL 3145.

    PubMed

    Uraih, N; Chipley, J R

    1976-01-01

    The effects of sodium chloride, sodium acetate, benzoic acid, sodium benzoate, malonic acid, and sodium malonate on growth and aflatoxin production by Aspergillus flavus were investigated in synthetic media. Sodium chloride at concentrations equivalent to or greater than 12 g/100 ml inhibited growth and aflatoxin production, while at 8 g or less/100 ml, growth and aflatoxin production were stimulated. At 2 g or less/100 ml, sodium acetate also stimulated growth and aflatoxin production, but reduction occurred with 4 g or more/100 ml. Malonic acid at 10, 20, 40, and 50 mM reduced growth and aflatoxin production (over 50%) while sodium malonate at similar concentrations but different pH values had the opposite effect. Benzoic acid (pH 3.9) and sodium benzoate (pH 5.0) at 0.4 g/100 ml completely inhibited growth and aflatoxin production. Examination of the effect of initial pH indicated that the extent of inhibitory action of malonic acid and sodium acetate was a function of initial pH. The inhibitory action of benzoic acid and sodium benzoate appeared to be a function of undissociated benzoic acid molecules. Aflatoxin reduction was usually accompanied by an unidentified orange pigment, while aflatoxin stimulation was accompanied by unidentified blue and green fluorescent spots but with lower Rf values that aflatoxins B1, G1, B2, and G2 standards.

  7. Correlation between aflatoxin contamination and various USDA grade categories of shelled almonds.

    PubMed

    Whitaker, Thomas B; Slate, Andy; Birmingham, Tim; Adams, Julie; Jacobs, Merle; Gray, Gary

    2010-01-01

    The California almond industry is interested in determining if there is a correlation between aflatoxin contamination and almonds classified into various U.S. Department of Agriculture (USDA) grades. A 12 000 g sample was taken from each of 50 lots of shelled almonds. The almonds in each sample were then partitioned into five USDA grades: high quality (HQ), insect damage (ID), mold damage (MOD), mechanical damage (MED), and other defects (OD). Across all 50 samples, kernels in the HQ grade accounted for 83.7% of the kernel mass and 3.2% of the aflatoxin mass. Conversely, kernels in the remaining four damage grades (ID, MOD, MED, and OD) accounted for 16.3% of the kernel mass and 96.8% of the aflatoxin mass. ID kernels had the highest risk for aflatoxin contamination. Almonds in the ID grade accounted for 76.3% of the total aflatoxin mass and 7.2% of the kernel mass. Regression equations were developed to predict the aflatoxin concentration in each 12 000 g sample by measuring the aflatoxin mass in one or more of the four damage grades. Regression equations demonstrated that aflatoxin mass only in the insect damaged kernels was also an effective way to predict the aflatoxin concentration in each 12 000 g sample.

  8. Sampling hazelnuts for aflatoxin: uncertainty associated with sampling, sample preparation, and analysis.

    PubMed

    Ozay, Guner; Seyhan, Ferda; Yilmaz, Aysun; Whitaker, Thomas B; Slate, Andrew B; Giesbrecht, Francis

    2006-01-01

    The variability associated with the aflatoxin test procedure used to estimate aflatoxin levels in bulk shipments of hazelnuts was investigated. Sixteen 10 kg samples of shelled hazelnuts were taken from each of 20 lots that were suspected of aflatoxin contamination. The total variance associated with testing shelled hazelnuts was estimated and partitioned into sampling, sample preparation, and analytical variance components. Each variance component increased as aflatoxin concentration (either B1 or total) increased. With the use of regression analysis, mathematical expressions were developed to model the relationship between aflatoxin concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific aflatoxin concentration. The sampling, sample preparation, and analytical variances associated with estimating aflatoxin in a hazelnut lot at a total aflatoxin level of 10 ng/g and using a 10 kg sample, a 50 g subsample, dry comminution with a Robot Coupe mill, and a high-performance liquid chromatographic analytical method are 174.40, 0.74, and 0.27, respectively. The sampling, sample preparation, and analytical steps of the aflatoxin test procedure accounted for 99.4, 0.4, and 0.2% of the total variability, respectively.

  9. Presence of aflatoxin M1 in commercial ultra-high-temperature-treated milk.

    PubMed Central

    Blanco, J L; Domínguez, L; Gómez-Lucía, E; Garayzabal, J F; García, J A; Suárez, G

    1988-01-01

    Forty-seven samples of commercial ultra-high-temperature-treated milk from a dairy facility in the northwest part of Spain were analyzed for the presence of aflatoxin M1. A total of 14 samples (29.8%) were positive for aflatoxin M1 (4 in May, 3 in November, 3 in December, 1 in January, 1 in April, 1 in July, and 1 in August), 29 (61.7%) were negative, and 4 (8.5%) were doubtful, i.e., they showed trace quantities of aflatoxin M1. The range of aflatoxin M1 content was 0.02 to 0.1 ng/ml. PMID:3137868

  10. Handling and aflatoxin contamination of white maize in Costa Rica.

    PubMed

    Mora, M; Lacey, J

    1997-01-01

    Projects funded by International Development Research Centre (IDRC) of Canada and the European Commission have enabled the examination of more than 3000 samples of maize collected from all regions of Costa Rica at different stages, from the growing crop through storage to final sale, and at different water contents. Contamination with Aspergillus flavus was frequent and about 80% of samples contained more than 20 ng aflatoxins g(-1) grain. Average contamination with aflatoxins in the Brunca Region was > 274 ng g(-1) while that in other regions was < 70 ng g(-1). Except in Brunca region, where it averaged 376 ng g(-1), contamination of grain from commercial sources was slightly less than of that from farms (< or = 15 ng g(-1)). It appeared that samples kept on the cob after harvest contained almost no aflatoxin while shelled samples were frequently highly contaminated. Experiments were therefore done in Brunca and Huetar Atlantic Regions, utilising 34 experimental maize crops to study in detail the development of A. flavus and aflatoxin from before harvest, through postharvest treatment before drying and through storage for six months. A. flavus was isolated more frequently from maize shelled immediately after harvest than from that kept on the cob until it could be dried, and from more samples from the Brunca Region than from the Huetar Atlantic Region. Samples harvested with > or = 18% water content often contains > 70% of grains infected with A. flavus but sometimes there were few grains infected. As found in the initial survey, more aflatoxin contamination developed in shelled maize than in that handled on the cob during the period from harvesting to drying, especially if the delay was more than 5 days, and more in Brunca than in Huetar. Shelled grain contained 400-800 ng aflatoxin g(-1) in Brunca but < 100 ng g(-1) in Huetar while grain kept on the cob contained < 30 ng g(-1), even with > 18% water content. Incidence of Fusarium spp. exceeded 50% except where A

  11. Estimated exposure to EU regulated mycotoxins and risk characterization of aflatoxin-induced hepatic toxicity through the consumption of the toasted cereal flour called "gofio", a traditional food of the Canary Islands (Spain).

    PubMed

    Luzardo, Octavio P; Bernal-Suárez, María Del Mar; Camacho, María; Henríquez-Hernández, Luis Alberto; Boada, Luis D; Rial-Berriel, Cristian; Almeida-González, Maira; Zumbado, Manuel; Díaz-Díaz, Ricardo

    2016-07-01

    "Gofio" is a type of flour made from toasted grain, which is part of the staple food in the Canary Islands, Spain, in which the occurrence of Aflatoxins B1, B2, G1 and G2 (AFB1, AFB2, AFG1, AFG2), Fumonisins B1 and B2 (FB1 and FB2) Ochratoxin A (OTA), Deoxynivalenol (DNV) and Zearalenone (ZEA) was evaluated. 83% of the samples were contaminated with at least one mycotoxin and 69.2% of the analyzed samples showed co-occurrence of mycotoxins (range 2 to 8). All the concentrations were well below the established limits (maximum values of AFs=0.42 μg/kg; FBs=178.3 μg/kg; OTA=0.3 μg/kg; DON=92.5 μg/kg; and ZEA=9.9 μg/kg). The daily dietary exposure to total AFs was estimated to be 7.1% of the TDI. This value was almost double in children, and considering the upper-bound approach could reach 35% of the TDI. For the rest of mycotoxins, the consumers would be exposed to less than 2% of their TDIs. The risk characterization indicates that there is a potential risk in developing aflatoxin induced liver cancer due to gofio consumption in the subpopulation which is simultaneously exposed to other hepatocarcinogens, such as the hepatitis B virus.

  12. Designer microbes for biosynthesis

    PubMed Central

    Quin, Maureen B.; Schmidt-Dannert, Claudia

    2014-01-01

    Microbes have long been adapted for the biosynthetic production of useful compounds. There is increasing demand for the rapid and cheap microbial production of diverse molecules in an industrial setting. Microbes can now be designed and engineered for a particular biosynthetic purpose, thanks to recent developments in genome sequencing, metabolic engineering, and synthetic biology. Advanced tools exist for the genetic manipulation of microbes to create novel metabolic circuits, making new products accessible. Metabolic processes can be optimized to increase yield and balance pathway flux. Progress is being made towards the design and creation of fully synthetic microbes for biosynthetic purposes. Together, these emerging technologies will facilitate the production of designer microbes for biosynthesis. PMID:24646570

  13. Microbial biosynthesis of alkanes.

    PubMed

    Schirmer, Andreas; Rude, Mathew A; Li, Xuezhi; Popova, Emanuela; del Cardayre, Stephen B

    2010-07-30

    Alkanes, the major constituents of gasoline, diesel, and jet fuel, are naturally produced by diverse species; however, the genetics and biochemistry behind this biology have remained elusive. Here we describe the discovery of an alkane biosynthesis pathway from cyanobacteria. The pathway consists of an acyl-acyl carrier protein reductase and an aldehyde decarbonylase, which together convert intermediates of fatty acid metabolism to alkanes and alkenes. The aldehyde decarbonylase is related to the broadly functional nonheme diiron enzymes. Heterologous expression of the alkane operon in Escherichia coli leads to the production and secretion of C13 to C17 mixtures of alkanes and alkenes. These genes and enzymes can now be leveraged for the simple and direct conversion of renewable raw materials to fungible hydrocarbon fuels.

  14. Terpenoid biosynthesis in prokaryotes.

    PubMed

    Boronat, Albert; Rodríguez-Concepción, Manuel

    2015-01-01

    Prokaryotic organisms (archaea and eubacteria) are found in all habitats where life exists on our planet. This would not be possible without the astounding biochemical plasticity developed by such organisms. Part of the metabolic diversity of prokaryotes was transferred to eukaryotic cells when endosymbiotic prokaryotes became mitochondria and plastids but also in a large number of horizontal gene transfer episodes. A group of metabolites produced by all free-living organisms is terpenoids (also known as isoprenoids). In prokaryotes, terpenoids play an indispensable role in cell-wall and membrane biosynthesis (bactoprenol, hopanoids), electron transport (ubiquinone, menaquinone), or conversion of light into chemical energy (chlorophylls, bacteriochlorophylls, rhodopsins, carotenoids), among other processes. But despite their remarkable structural and functional diversity, they all derive from the same metabolic precursors. Here we describe the metabolic pathways producing these universal terpenoid units and provide a complete picture of the main terpenoid compounds found in prokaryotic organisms.

  15. Biosynthesis of methanopterin

    SciTech Connect

    White, R.H. )

    1990-06-05

    The biosynthetic pathway for the generation of the methylated pterin in methanopterins was determined for the methanogenic bacteria Methanococcus volta and Methanobacterium formicicum. Extracts of M. volta were found to readily cleave L-7,8-dihydroneopterin to 7,8-dihydro-6-(hydroxymethyl)pterin, which was confirmed to be a precursor of the pterin portion of the methanopterin. (methylene{sup 2}H)-6-(hydroxymethyl)pterin was incorporated into methanopterin by growing cells of M. volta to an extent of 30%. Both the C-11 and C-12 methyl groups of methanopterin originate from (methyl-{sup 2}H{sub 3})methionine. Cells grown in the presence of (methylene-{sup 2}H)-6-(hydroxymethyl)pterin, (ethyl-{sup 2}H{sub 4})-6-(1 (RS)-hydroxyethyl)pterin, (methyl-{sup 2}H{sub 3})-6-(hydroxymethyl)-7-methylpterin, (ethyl-{sup 2}H{sub 4}, methyl-{sup 2}H{sub 3})-6-(1 (RS)-hydroxyethyl)-7-methylpterin, and (1-ethyl-{sup 3}H)-6-(1 (RS)-hydroxyethyl)-7-methylpterin showed that only the non-7-methylated pterins were incorporated into methanopterin. Cells extracts of M. formicicum readily condensed synthetic (methylene-{sup 3}H)-7,8-H{sub 2}-6-(hydroxymethyl)pterin-PP with methaniline to generate demethylated methanopterin, which is then methylated to methanopterin by the cell extract in the presence of S-adenosylmethionine. These observations indicate that the pterin portion of methanopterin is biosynthetically derived from 7,8-H{sub 2}-6-(hydroxymethyl)pterin, which is coupled to methaniline by a pathway analogous to the biosynthesis of folic acid. This pathway for the biosynthesis of methanopterin represents the first example of the modification of the specificity of a coenzyme through a methylation reaction.

  16. Methionine Biosynthesis in Lemna

    PubMed Central

    Thompson, Gregory A.; Datko, Anne H.; Mudd, S. Harvey; Giovanelli, John

    1982-01-01

    Regulation of enzymes of methionine biosynthesis was investigated by measuring the specific activities of O-phosphohomoserine-dependent cystathionine γ-synthase, O-phosphohomoserine sulfhydrylase, and O-acetylserine sulfhydrylase in Lemna paucicostata Hegelm. 6746 grown under various conditions. For cystathionine γ-synthase, it was observed that (a) adding external methionine (2 μm) decreased specific activity to 15% of control, (b) blocking methionine synthesis with 0.05 μml-aminoethoxyvinylglycine or with 36 μm lysine plus 4 μm threonine (Datko, Mudd 1981 Plant Physiol 69: 1070-1076) caused a 2- to 3-fold increase in specific activity, and (c) blocking methionine synthesis and adding external methionine led to the decreased specific activity characteristic of methionine addition alone. Activity in extracts from control cultures was unaffected by addition of methionine, lysine, threonine, lysine plus threonine, S-adenosylmethionine, or S-methylmethionine sulfonium to the assay mixture. Parallel studies of O-phosphohomoserine sulfhydrylase and O-acetylserine sulfhydrylase showed that O-phosphohomoserine sulfhydrylase activity responded to growth conditions identically to cystathionine γ-synthase activity, whereas O-acetylserine sulfhydrylase activity remained unaffected. Lemna extracts did not catalyze lanthionine formation from O-acetylserine and cysteine. Estimates of kinetic constants for the three enzyme activities indicate that O-acetylserine sulfhydrylase has much higher activity and affinity for sulfide than O-phosphohomoserine sulfhydrylase. The results suggest that (a) methionine, or one of its products, regulates the amount of active cystathionine γ-synthase in Lemna, (b) O-phosphohomoserine sulfhydrylase and cystathionine γ-synthase are probably activities of one enzyme that has low specificity for its sulfur-containing substrate, and (c) O-acetylserine sulfhydrylase is a separate enzyme. The relatively high activity and affinity for sulfide of

  17. Effects of Bacillus subtilis ANSB060 on growth performance, meat quality and aflatoxin residues in broilers fed moldy peanut meal naturally contaminated with aflatoxins.

    PubMed

    Fan, Yu; Zhao, Lihong; Ma, Qiugang; Li, Xiaoying; Shi, Huiqin; Zhou, Ting; Zhang, Jianyun; Ji, Cheng

    2013-09-01

    This study was conducted to investigate the toxic effects of aflatoxins and the efficacy of Bacillus subtilis ANSB060 for the amelioration of aflatoxicosis in broiler chickens. Six replicates of ten broilers each were assigned to one of seven dietary treatments, which were labeled C0 (basal diet); M0 (basal diet containing moldy peanut meal); C500 and C1000 (C0+500 or 1000 g/t aflatoxin biodegradation preparations, composed mainly of ANSB060); and M500, M1000 and M2000 (M0+500, 1000 or 2000 g/t aflatoxin biodegradation preparations). The concentrations of aflatoxin B₁, B₂, G₁ and G₂ in the moldy diets (M0, M500, M100 and M2000) fluctuated around 70.7±1.3, 11.0±1.5, 6.5±0.8 and 2.0±0.3 μg/kg, respectively. The results showed that the M0 diet caused a significant decrease in average daily weight gain and increased feed requirements, with a gain ratio increasing from d 8 to 42, deterioration in meat quality and aflatoxin residues in broilers' livers as compared with the C0 diet. The addition of ANSB060 to the aflatoxin-contaminated diets offset these negative effects, leading to the conclusion that ANSB060 has a protective effect on growth performance and meat quality while reducing the amount of aflatoxin residues in the livers of broilers fed naturally moldy peanut meal.

  18. Determination of aflatoxin risk components for in-shell Brazil nuts.

    PubMed

    Vargas, E A; dos Santos, E A; Whitaker, T B; Slate, A B

    2011-09-01

    A study was conducted on the risk from aflatoxins associated with the kernels and shells of Brazil nuts. Samples were collected from processing plants in Amazonia, Brazil. A total of 54 test samples (40 kg) were taken from 13 in-shell Brazil nut lots ready for market. Each in-shell sample was shelled and the kernels and shells were sorted in five fractions: good kernels, rotten kernels, good shells with kernel residue, good shells without kernel residue, and rotten shells, and analysed for aflatoxins. The kernel:shell ratio mass (w/w) was 50.2/49.8%. The Brazil nut shell was found to be contaminated with aflatoxin. Rotten nuts were found to be a high-risk fraction for aflatoxin in in-shell Brazil nut lots. Rotten nuts contributed only 4.2% of the sample mass (kg), but contributed 76.6% of the total aflatoxin mass (µg) in the in-shell test sample. The highest correlations were found between the aflatoxin concentration in in-shell Brazil nuts samples and the aflatoxin concentration in all defective fractions (R(2)=0.97). The aflatoxin mass of all defective fractions (R(2)=0.90) as well as that of the rotten nut (R(2)=0.88) were also strongly correlated with the aflatoxin concentration of the in-shell test samples. Process factors of 0.17, 0.16 and 0.24 were respectively calculated to estimate the aflatoxin concentration in the good kernels (edible) and good nuts by measuring the aflatoxin concentration in the in-shell test sample and in all kernels, respectively.

  19. Fungal Biodeterioration, Aflatoxin Contamination, and Nutrient Value of “Suya Spices”

    PubMed Central

    Jonathan, Segun Gbolagade; Adeniyi, Mary Adejoke; Asemoloye, Michael Dare

    2016-01-01

    This work aimed to analyze the nutrient values, examine the biodeteriorating fungi biota, and analyze the mycotoxin contents of “Suya spices.” Fungi with highest percentage occurrence on all the samples are Aspergillus niger, Aspergillus flavus, Aspergillus parasiticus, Aspergillus ochraceus, Fusarium sp., Rhizopus stolonifer, yeast, and Trichoderma koningii. Nutrient composition of the samples is significantly different statistically (P < 0.05) with high protein (9.53% to 13.17%), fiber (9.27 to 13.17%), carbohydrate (46.27% to 50.90%), and ash (8.47% to 9.70%) contents but low moisture (9.03% to 9.47%) and fat (9.77% to 13.53%) contents. Aflatoxin analysis of the samples revealed that they all contain aflatoxin in varying amount but no detectible aflatoxin content in the control. 59.54% of the detected aflatoxin is aflatoxin B1 with highest recorded in Agbowo, Mokola, and Sango samples (i.e., 28.03, 22.44, and 13.8 μg/kg, resp.). 4.78% of the aflatoxin is aflatoxin B2 which is only found in Sango and Mokola samples (3.59 and 2.6 μg/kg, resp.). 32.76% of aflatoxin is aflatoxin G1 with the highest found in Agbowo and Mokola samples (i.e., 18.63 and 10.41 μg/kg, resp.). 2.93% of the aflatoxin is aflatoxin G2 which is only detected in Sango and Agbowo samples (i.e., 1.19 and 2.65 μg/kg, resp.). PMID:27092289

  20. Reduction of Aflatoxins in Apricot Kernels by Electronic and Manual Color Sorting

    PubMed Central

    Zivoli, Rosanna; Gambacorta, Lucia; Piemontese, Luca; Solfrizzo, Michele

    2016-01-01

    The efficacy of color sorting on reducing aflatoxin levels in shelled apricot kernels was assessed. Naturally-contaminated kernels were submitted to an electronic optical sorter or blanched, peeled, and manually sorted to visually identify and sort discolored kernels (dark and spotted) from healthy ones. The samples obtained from the two sorting approaches were ground, homogenized, and analysed by HPLC-FLD for their aflatoxin content. A mass balance approach was used to measure the distribution of aflatoxins in the collected fractions. Aflatoxin B1 and B2 were identified and quantitated in all collected fractions at levels ranging from 1.7 to 22,451.5 µg/kg of AFB1 + AFB2, whereas AFG1 and AFG2 were not detected. Excellent results were obtained by manual sorting of peeled kernels since the removal of discolored kernels (2.6%–19.9% of total peeled kernels) removed 97.3%–99.5% of total aflatoxins. The combination of peeling and visual/manual separation of discolored kernels is a feasible strategy to remove 97%–99% of aflatoxins accumulated in naturally-contaminated samples. Electronic optical sorter gave highly variable results since the amount of AFB1 + AFB2 measured in rejected fractions (15%–18% of total kernels) ranged from 13% to 59% of total aflatoxins. An improved immunoaffinity-based HPLC-FLD method having low limits of detection for the four aflatoxins (0.01–0.05 µg/kg) was developed and used to monitor the occurrence of aflatoxins in 47 commercial products containing apricot kernels and/or almonds commercialized in Italy. Low aflatoxin levels were found in 38% of the tested samples and ranged from 0.06 to 1.50 μg/kg for AFB1 and from 0.06 to 1.79 μg/kg for total aflatoxins. PMID:26797635

  1. Reduction of Aflatoxins in Apricot Kernels by Electronic and Manual Color Sorting.

    PubMed

    Zivoli, Rosanna; Gambacorta, Lucia; Piemontese, Luca; Solfrizzo, Michele

    2016-01-19

    The efficacy of color sorting on reducing aflatoxin levels in shelled apricot kernels was assessed. Naturally-contaminated kernels were submitted to an electronic optical sorter or blanched, peeled, and manually sorted to visually identify and sort discolored kernels (dark and spotted) from healthy ones. The samples obtained from the two sorting approaches were ground, homogenized, and analysed by HPLC-FLD for their aflatoxin content. A mass balance approach was used to measure the distribution of aflatoxins in the collected fractions. Aflatoxin B₁ and B₂ were identified and quantitated in all collected fractions at levels ranging from 1.7 to 22,451.5 µg/kg of AFB₁ + AFB₂, whereas AFG₁ and AFG₂ were not detected. Excellent results were obtained by manual sorting of peeled kernels since the removal of discolored kernels (2.6%-19.9% of total peeled kernels) removed 97.3%-99.5% of total aflatoxins. The combination of peeling and visual/manual separation of discolored kernels is a feasible strategy to remove 97%-99% of aflatoxins accumulated in naturally-contaminated samples. Electronic optical sorter gave highly variable results since the amount of AFB₁ + AFB₂ measured in rejected fractions (15%-18% of total kernels) ranged from 13% to 59% of total aflatoxins. An improved immunoaffinity-based HPLC-FLD method having low limits of detection for the four aflatoxins (0.01-0.05 µg/kg) was developed and used to monitor the occurrence of aflatoxins in 47 commercial products containing apricot kernels and/or almonds commercialized in Italy. Low aflatoxin levels were found in 38% of the tested samples and ranged from 0.06 to 1.50 μg/kg for AFB₁ and from 0.06 to 1.79 μg/kg for total aflatoxins.

  2. Sampling almonds for aflatoxin, part I: estimation of uncertainty associated with sampling, sample preparation, and analysis.

    PubMed

    Whitaker, Thomas B; Slate, Andrew B; Jacobs, Merle; Hurley, J Michael; Adams, Julie G; Giesbrecht, Francis G

    2006-01-01

    Domestic and international regulatory limits have been established for aflatoxin in almonds and other tree nuts. It is difficult to obtain an accurate and precise estimate of the true aflatoxin concentration in a bulk lot because of the uncertainty associated with the sampling, sample preparation, and analytical steps of the aflatoxin test procedure. To evaluate the performance of aflatoxin sampling plans, the uncertainty associated with sampling lots of shelled almonds for aflatoxin was investigated. Twenty lots of shelled almonds were sampled for aflatoxin contamination. The total variance associated with measuring B1 and total aflatoxins in bulk almond lots was estimated and partitioned into sampling, sample preparation, and analytical variance components. All variances were found to increase with an increase in aflatoxin concentration (both B1 and total). By using regression analysis, mathematical expressions were developed to predict the relationship between each variance component (total, sampling, sample preparation, and analysis variances) and aflatoxin concentration. Variance estimates were the same for B1 and total aflatoxins. The mathematical relationships can be used to estimate each variance for a given sample size, subsample size, and number of analyses other than that measured in the study. When a lot with total aflatoxins at 15 ng/g was tested by using a 10 kg sample, a vertical cutter mixer type of mill, a 100 g subsample, and high-performance liquid chromatography analysis, the sampling, sample preparation, analytical, and total variances (coefficient of variation, CV) were 394.7 (CV, 132.4%), 14.7 (CV, 25.5%), 0.8 (CV, 6.1%), and 410.2 (CV, 135.0%), respectively. The percentages of the total variance associated with sampling, sample preparation, and analytical steps were 96.2, 3.6, and 0.2, respectively.

  3. Uncommon occurrence ratios of aflatoxin B1, B 2, G 1, and G 2 in maize and groundnuts from Malawi.

    PubMed

    Matumba, Limbikani; Sulyok, Michael; Njoroge, Samuel M C; Njumbe Ediage, Emmanuel; Van Poucke, Christof; De Saeger, Sarah; Krska, Rudolf

    2015-02-01

    We report an unusual aflatoxin profile in maize and groundnuts from Malawi, with aflatoxin G1 found routinely at equal or even higher levels than aflatoxin B1. Aflatoxin B1 (AFB1) ratio in a contaminated sample is generally greater than 50% of total aflatoxin (sum of aflatoxin B1, B2, G1, and G2). In Malawi, the aflatoxin occurrence ratios were determined by examining LC-MS/MS and HPLC fluorescence detection (FLD) data of 156 naturally contaminated raw maize and 80 groundnut samples collected in 2011 and 2012. Results showed that natural aflatoxin occurrence ratio differed. In 47% of the samples, the concentration of AFG1 was higher than that of AFB1. The mean concentration percentages of AFB1/AFB2/AFG1/AFG2 in reference to total aflatoxins were found to be 47:5:43:5%, respectively. The AFG1 and AFB1 50/50 trend was observed in maize and groundnuts and was consistent for samples collected in both years. If the AFB1 measurement was used to check compliance of total aflatoxin regulatory limit set at 10, 20, 100, and 200 μg/kg with an assumption that AFB1≥50% of the total aflatoxin content, 8, 13, 24, and 26% false negative rates would have occurred respectively. It is therefore important for legislation to consider total aflatoxins rather than AFB1 alone.

  4. Fluorescence imaging spectroscopy (FIS) for comparing spectra from corn ears naturally and artificially infected with aflatoxin producing fungus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In an effort to address the aflatoxin problem in grain, the current study assessed the spectral differences of aflatoxin production in kernels from a cornfield inoculated with spores from two different strains of toxigenic Aspergillus flavus. Aflatoxin production in corn from the same field due to n...

  5. Diversity of aflatoxin-producing fungi and their impact on food safety in sub-Saharan Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crops frequently contaminated by aflatoxins are important sources of revenue and daily nourishment in many portions of sub-Saharan Africa. In recent years, reports have associated aflatoxins with diminished human health and export opportunities in many African Nations. Aflatoxins are highly carcinog...

  6. Sampling hazelnuts for aflatoxin: Effects of sample size and accetp/reject limit on reducing risk of misclassifying lots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    About 100 countries have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely among regulating countries, the Codex Committee on Food Additives and Contaminants (CCFAC) began work in 2004 to harmonize aflatoxin limits and sampling plans for aflatoxin in alm...

  7. The regulation of ascorbate biosynthesis.

    PubMed

    Bulley, Sean; Laing, William

    2016-10-01

    We review the regulation of ascorbate (vitamin C) biosynthesis, focusing on the l-galactose pathway. We discuss the regulation of ascorbate biosynthesis at the level of gene transcription (both repression and enhancement) and translation (feedback inhibition of translation by ascorbate concentration) and discuss the eight proteins that have been demonstrated to date to affect ascorbate concentration in plant tissues. GDP-galactose phosphorylase (GGP) and GDP-mannose epimerase are critical steps that regulate ascorbate biosynthesis. These and other biosynthetic genes are controlled at the transcriptional level, while GGP is also controlled at the translational level. Ascorbate feedback on enzyme activity has not been observed unequivocally.

  8. Aflatoxin Regulations in a Network of Global Maize Trade

    PubMed Central

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000–2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B1, B2, G1, and G2) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards. PMID:23049773

  9. Aflatoxin regulations in a network of global maize trade.

    PubMed

    Wu, Felicia; Guclu, Hasan

    2012-01-01

    Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000-2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B(1), B(2), G(1), and G(2)) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

  10. Aflatoxins in Rice Artificially Contaminated with Aflatoxin-producing Aspergillus flavus under Natural Storage in Japan.

    PubMed

    Sugihara, Satoshi; Doi, Hiroyuki; Kato, Masahiko; Mitoh, Yoshihiro; Tsuda, Toshihide; Ikeda, Satoru

    2016-06-01

    Aflatoxin (AFT) contamination is frequent in foods grown in tropical regions, including rice. Although AFTs are generally not found in temperate-region foods, global warming has affected typical temperate-region climates, potentially permitting the contamination of foods with AFT-producing Aspergillus flavus (A. flavus). Here we investigated the AFT production in rice during storage under natural climate conditions in Japan. We examined AFTs in brown rice and rough rice artificially contaminated with A. flavus for 1 year in Japan, and we subjected AFTs in white rice to the same treatment in airtight containers and examined the samples in warm and cold seasons, simulating the storage of white rice in general households. In the brown rice, AFTs increased after 2 months (March) and peaked after 9 months (October). The AFT contamination in the rough rice was minimal. After the polishing and cooking of the brown rice, AFTs were undetectable. In the white rice stored in airtight containers, AFTs increased after 1 month (August) and peaked after 2 months (September). Minimal AFTs were detected in the cold season. Thus, AFT contamination in rice may occur in temperate regions following A. flavus contamination. The storage of rice as rough rice could provide be useful for avoiding AFT contamination.

  11. Metabolism of aflatoxin B-1 in cotton bolls

    SciTech Connect

    Mellon, J.E.; Lee, L.S. )

    1989-04-01

    Aspergillus flavus is a fungus capable of producing the potent carcinogen aflatoxin (AFB-1) when it infects developing cotton seed. Although high levels of toxin can readily be isolated from internal tissues of infected seeds, very low toxin levels are observed in the fiber-linter matrix. In order to test the hypothesis that constituents associated with the lint of the host plant are metabolizing aflatoxin, {sup 14}C-AFB-1 was introduced into cotton bolls (30 days postanthesis). Other sets of bolls received inoculations of toxigenic or nontoxigenic strains of A. flavus plus exogenous {sup 14}C-AFB-1. In addition to the exogenously applied {sup 14}C-AFB-1, at least two new labelled metabolites were recovered from the test bolls. One of these metabolites was very polar and remained on the origin of the thin layer analysis system. Test bolls which received both A. flavus and AFB-1 produced significantly lower levels of this polar metabolite. Results indicated that some constituent(s) associated with cotton fiber may metabolize fungal-produced aflatoxin, rather than inhibit its formation.

  12. Pulmonary interstitial fibrosis with evidence of aflatoxin B1 in lung tissue

    SciTech Connect

    Dvorackova, I.; Pichova, V.

    1986-01-01

    Three cases of pulmonary interstitial fibrosis, two in agricultural workers and one in a textile worker, are reported. In lung samples of all three patients the presence of aflatoxin B1 was demonstrated by radioimmunoassay (RIA). A possible occupational risk of aflatoxin exposure via the respiratory tract is suggested.

  13. Integrated process for ammonia inactivation of aflatoxin-contaminated corn and ethanol fermentation

    SciTech Connect

    Bothast, R.J.; Nofsinger, G.W.; Lagoda, A.A.; Black, L.T.

    1982-04-01

    A process is described for converting aflatoxin-contaminated corn to ethanol via combining ammonia inactivation with the liquefaction step of the ethanol fermentation process. Better ethanol yields were obtained when ammonia was added during liquefaction than when no ammonia was added. Aflatoxin B/sub 1/ levels were reduced 80 to 85% by the process.

  14. Oral administration of piperine for the control of aflatoxin intoxication in rats

    PubMed Central

    Gagini, Thalita B.; Silva, Robson E.; Castro, Isabela S.; Soares, Breno A.; Lima, Marco E.F.; Brito, Marilene F.; Mazur, Carlos; Direito, Glória M.; Danelli, Maria das Graças M.

    2010-01-01

    Aflatoxins are mycotoxins that have important toxic effects on human and animal health, even if consumed at low doses. The oral administration of piperine (1.12 mg/kg) during 23 days in rats seemingly interfered with the toxicity of aflatoxins, decreasing hepatic injuries and the leukocyte depletion in experimentally intoxicated animals. PMID:24031502

  15. Maize Aflatoxin Accumulation Segregates with Early Maturing Selections from an S2 Breeding Cross Population

    PubMed Central

    Henry, W. Brien

    2013-01-01

    Maize breeders continue to seek new sources of aflatoxin resistance, but most lines identified as resistance sources are late maturing. The vast difference in flowering time makes it hard to cross these lines with proprietary commercial lines that mature much earlier and often subjects the reproductive phase of these resistant lines to the hottest and driest portion of the summer, making silking, pollination and grain fill challenging. Two hundred crosses from the GEM Project were screened for aflatoxin accumulation at Mississippi State in 2008, and a subset of these lines were screened again in 2009. The breeding cross UR13085:S99g99u was identified as a potential source of aflatoxin resistance, and maturity-based selections were made from an S2 breeding population from this same germplasm source: UR13085:S99g99u-B-B. The earliest maturing selections performed poorly for aflatoxin accumulation, but later maturing selections were identified with favorable levels of aflatoxin accumulation. These selections, while designated as “late” within this study, matured earlier than most aflatoxin resistant lines presently available to breeders. Two selections from this study, designated S5_L7 and S5_L8, are potential sources of aflatoxin resistance and will be advanced for line development and additional aflatoxin screening over more site years and environments. PMID:23322131

  16. Process Development for Spray Drying a Value-Added Extract from Aflatoxin Contaminated Peanut Meal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut meal, the primary byproduct of commercial oil crushing operations, is an excellent source of protein though aflatoxin contamination often limits applications for this material. Naturally aflatoxin contaminated (59 ppb) peanut meal dispersions were adjusted to pH 2.1 or pH 9.1, with or without...

  17. Incidence and Level of Aflatoxins Contamination in Medicinal Plants in Korea

    PubMed Central

    Lee, Sung Deuk; Yu, In Sil; Jung, Kweon

    2014-01-01

    During 2011~2013, a total of 729 samples for 19 types of medicinal plant were collected from Seoulyekryungsi in Seoul, Korea, and investigated for the presence of aflatoxins. The samples were analyzed using immunoaffinity column cleanup and high-performance liquid chromatography coupled to a fluorescence detector after post-column derivatization. Aflatoxins were found in 124 out of the 729 analyzed samples: 65 containing aflatoxin B1 (AFB1), 24 with aflatoxin B2 (AFB2), 15 with aflatoxin G1 (AFG1), and 20 samples with aflatoxin G2 (AFG2). The ranges for positive samples were 0.1~404.7 µg/kg for AFB1, 0.1~10.0 µg/kg for AFB2, 0.1~635.3 µg/kg for AFG1, 0.1~182.5 µg/kg for AFG2, and 0.1~1,043.9 µg/kg for total aflatoxins. Most of the medicinal plant samples (721, 98.9%) were below legal limits, but 8 samples exceeded the legal limits of 10 and 15 µg/kg established by the Korean standard for AFB1 and total aflatoxins (the sum of AFB1, AFB2, AFG1 and AFG2), respectively. PMID:25606005

  18. Analysis of genetic and aflatoxin diversity among Aspergillus flavus strains isolated from sorghum seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A total of 34 A. flavus isolates were recovered from sorghum seeds sampled across five states in India. Our study included (1) species confirmation through PCR assay, (2) an aflatoxin cluster genotype assay using developed multiplex PCR, (3) quantification of total aflatoxin concentrations by the iC...

  19. Transport via xylem and accumulation of aflatoxin in seeds of groundnut plant.

    PubMed

    Snigdha, M; Hariprasad, P; Venkateswaran, G

    2015-01-01

    Aflatoxin contamination in groundnut seeds in the absence of any aflatoxigenic fungi leads to a hypothesis that aflatoxins are present naturally in soil and is transferred to seeds through uptake by roots. A survey was conducted on the natural occurrence of aflatoxins in agricultural soils, among nine main groundnut-growing regions of Karnataka state, India. All 71 soil samples collected in this survey were contaminated with aflatoxins esp. AFB1. An in vitro xylem sap experiment proved the ability of groundnut plant roots to absorb AFB1, and transport to aerial plant parts via the xylem. Hydroponics experiment also proved the uptake of AFB1 by the roots and their translocation to shoot. Uptake was affected by the initial concentration of toxin and pH of the medium. Among the 14 varieties screened, GPBD4 and MLT.K.107 (III) recorded highest and least AFB1 uptake, respectively. The above results were validated using a greenhouse experiment. Here, the aflatoxin absorbed by root gradually transferred to shoot that was later found in seeds towards the end of experiment. Thus, the groundnut seeds can also get contaminated with aflatoxin by direct uptake of aflatoxin through conducting tissue in addition to fungal infection. The present study revealed the novel mode of aflatoxin contamination in groundnut seeds without fungal infection.

  20. Aflatoxin production by entomopathogenic isolates of Aspergillus parasiticus and Aspergillus flavus.

    PubMed

    Drummond, J; Pinnock, D E

    1990-05-01

    Fourteen isolates of Aspergillus parasiticus and 2 isolates of Aspergillus flavus isolated from the mealybug Saccharicoccus sacchari were analyzed for production of aflatoxins B1, B2, G1, and G2 in liquid culture over a 20-day period. Twelve Aspergillus isolates including 11 A. parasiticus and 1 A. flavus produced aflatoxins which were extracted from both the mycelium and culture filtrate. Aflatoxin production was detected at day 3 and was detected continually for up to day 20. Aflatoxin B1 production was greatest between 7 and 10 days and significantly higher quantities were produced by A. flavus compared to A. parasiticus. Aflatoxin production was not a stable trait in 1 A. parasiticus isolate passaged 50 times on agar. In addition to loss of aflatoxin production, an associated loss in sporulation ability was also observed in this passaged isolate, although it did maintain pathogenicity against S. sacchari. An aflatoxin B1 concentration of 0.16 micrograms/mealybug (14.2 micrograms/g wet wt) was detected within the tissues of infected mealybugs 7 days after inoculation. In conclusion, the ability of Aspergillus isolates to produce aflatoxins was not essential to the entomopathogenic activity of this fungus against its host S. sacchari.

  1. Aflatoxin production and environmental oxidative stress in Aspergillus flavus: Implications forhost resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contamination of maize kernel tissues with aflatoxin is of major concern in global food production, particularly in developing countries. Resistance to aflatoxin is negatively influenced by environmental stress, namely drought stress. Given that reactive oxygen species (ROS) are known to accumul...

  2. NsdC and NsdD affect Aspergillus flavus morphogenesis and aflatoxin production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The transcription factors NsdC and NsdD have been shown to be necessary for sexual development in Aspergillus nidulans. Herein we examine the role of these proteins in development and aflatoxin production of the agriculturally important, aflatoxin-producing fungus, Aspergillus flavus. We found tha...

  3. Combining genomic approaches to understand genetic control of aflatoxin contamination in peanut

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination in peanut is more prevalent under rainfed conditions making produce unfit for human and animal consumption, affecting the international trade adversely. Although the losses in yield and quality due to aflatoxin contamination is higher than realized, there are limited resistan...

  4. Atoxigenic Aspergillus flavus endemic to Italy for biocontrol of aflatoxins in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effective biological control of aflatoxin­producing Aspergillus flavus with atoxigenic members of that species requires suitable A. flavus well adapted to and resident in target agroecosystems. Eighteen atoxigenic isolates of A. flavus endemic in Italy were compared for ability to reduce aflatoxin c...

  5. Introduction to the Toxin Reviews Special Issue "Aspergillus, Aflatoxin, Cyclopiazonic Acid, and Biological Control"

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This special issue of Toxin Reviews, “Aspergillus, Aflatoxin, CPA and Biological Control of Aflatoxin", is different from previous publications because it focuses on solving the problem of mycotoxin contamination through the use of biological control strains of Aspergillus, which is applicable to th...

  6. Non-aflatoxigenic Aspergillus flavus isolates reduce aflatoxins, cyclopiazonic acid and fumonisin in corn (maize)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspergillus flavus strains vary widely in their production of aflatoxins and cyclopiazonic acid (CPA). A total of 500 Aspergillus strains isolated from a variety of sources showed 16.4% were negative for both aflatoxin and CPA, 41.3% were positive for both mycotoxins, 13.0% were positive only fo...

  7. Biological control of aflatoxin is effective and economical in Mississippi field trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin contamination of corn is a major grain quality issue and can be a major economic limiting factor to Mississippi corn farmers. Biological control products based on aflatoxin non-producing strains of Aspergillus flavus are commercially available to prevent the contamination of corn with afl...

  8. Quantitative trait loci (QTL) for reducing Aspergillus flavus infection and aflatoxin accumulation in corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin produced by Aspergillus flavus in corn poses significant health risks for both humans and livestock. Corn growers suffer huge economic losses due to increased aflatoxin accumulation in grain especially under drought and higher temperature stress conditions. Exploitation of host plant resi...

  9. Association between aflatoxin contamination and N2 fixation in peanut under drought conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traits related to nitrogen fixation may be used as indirect selection criteria for aflatoxin resistance in peanut. The aim of this study was to investigate the relationship between N2 fixation traits and aflatoxin contamination in peanut under different drought conditions. Eleven peanut genotypes we...

  10. Association between surrogate traits of drought tolerance and aflatoxin contamination in peanut cultivars under terminal drought

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Terminal drought induces pre-harvest aflatoxin contamination (PAC). Drought resistance traits are promising as indirect selection tools for improving resistance to PAC. The objectives of this study were to determine the effects of terminal drought on Aspergillus invasion and aflatoxin contamination ...

  11. Simple, rapid, and inexpensive cleanup method for quantitation of aflatoxins in important agricultural products by HPLC.

    PubMed

    Sobolev, Victor S

    2007-03-21

    A chemical cleanup procedure for low-level quantitative determination of aflatoxins in major economically important agricultural commodities using HPLC has been developed. Aflatoxins were extracted from a ground sample with MeOH/H2O (80:20, v/v), and after a cleanup step on a minicolumn packed with Florisil, aflatoxins were quantified by HPLC equipped with a C18 column, a photochemical reactor, and a fluorescence detector. Water/MeOH (63:37, v/v) served as the mobile phase. Recoveries of aflatoxins B1, B2, G1, and G2 from peanuts spiked at 5, 1.7, 5, and 1.7 ng/g were 89.5+/-2.2, 94.7+/-2.5, 90.4+/-1.0, and 98.2+/-1.1, respectively (mean+/-SD, %, n=3). Similar recoveries, precision, and accuracy were achieved for corn, brown and white rice, cottonseed, almonds, Brazil nuts, pistachios, walnuts, and hazelnuts. The quantitation limits for aflatoxins in peanuts were 50 pg/g for aflatoxin B1 and 17 pg/g for aflatoxin B2. The minimal cost of the minicolumn allows for substantial savings compared with available commercial aflatoxin cleanup devices.

  12. Assessment of Adoption Gaps in Management of Aflatoxin Contamination of Groundnut ("Arachis Hypogaea" L.)

    ERIC Educational Resources Information Center

    Kumar, G. D. S.; Popat, M. N.

    2010-01-01

    One of the major impediments for diversification of groundnut ("Arachis Hypogaea" L.) as food crop is aflatoxin contamination. The study was conducted with an objective to assess the adoption gaps in aflatoxin management practices of groundnut (AMPG) and the farmer's characteristics influencing these gaps. The study used an expost-facto…

  13. Efficacy of water dispersible formulations of biocontrol strains of Aspergillus flavus for aflatoxin management in corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field experiments were conducted in 2011 and 2012 to evaluate the efficacy of water dispersible granule (WDG) formulations of biocontrol strains of Aspergillus flavus in controlling aflatoxin contamination of corn. In 2011, when aflatoxin was present at very high levels, no WDG treatment provided s...

  14. 75 FR 43045 - Pistachios Grown in California, Arizona, and New Mexico; Modification of the Aflatoxin Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... shipped for domestic human consumption while maintaining sufficient aflatoxin controls. It is expected to... order's rules and regulations for pistachios to be shipped for domestic human consumption, while... pistachios to be sampled and tested for aflatoxin prior to being shipped for domestic human...

  15. Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B₁.

    PubMed

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-11-13

    Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

  16. RNA interference reduces aflatoxin accumulation by Aspergillus flavus in peanut seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxins are among the most powerful carcinogens in nature. They are produced by the fungal pathogen Aspergillus flavus Link and other Aspergillus species. Aflatoxins accumulate in many crops, including rice, wheat, oats, pecans, pistachios, soybean, cassava, almonds, peanuts, beans, corn and cot...

  17. Development of narrow-band fluorescence index for the detection of aflatoxin contaminated corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin is produced by the fungus Aspergillus flavus when the fungus invades developing corn kernels. Because of its potent toxicity, the levels of aflatoxin are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food, and feed intended for...

  18. Using Genome-Wide Associations to Identify Metabolic Pathways Involved in Maize Aflatoxin Accumulation Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin is a potent carcinogen that can contaminate grain infected with the fungus Aspergillus flavus. However, resistance to aflatoxin accumulation in maize is a complex trait with low heritability. Here, two complementary analyses were performed to better understand the mechanisms involved. T...

  19. Genome wide association mapping of Aspergillus flavus and aflatoxin accumulation resistance in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Contamination of maize with aflatoxin, produced by the fungus Aspergillus flavus, has severe health and economic consequences. Efforts to reduce aflatoxin accumulation in maize have focused on identifying and selecting germplasm with natural host resistance factors, and several maize lines with sign...

  20. Degradation of AF1Q by chaperone-mediated autophagy

    SciTech Connect

    Li, Peng; Ji, Min; Lu, Fei; Zhang, Jingru; Li, Huanjie; Cui, Taixing; Li Wang, Xing; Tang, Dongqi; Ji, Chunyan

    2014-09-10

    AF1Q, a mixed lineage leukemia gene fusion partner, is identified as a poor prognostic biomarker for pediatric acute myeloid leukemia (AML), adult AML with normal cytogenetic and adult myelodysplastic syndrome. AF1Q is highly regulated during hematopoietic progenitor differentiation and development but its regulatory mechanism has not been defined clearly. In the present study, we used pharmacological and genetic approaches to influence chaperone-mediated autophagy (CMA) and explored the degradation mechanism of AF1Q. Pharmacological inhibitors of lysosomal degradation, such as chloroquine, increased AF1Q levels, whereas activators of CMA, including 6-aminonicotinamide and nutrient starvation, decreased AF1Q levels. AF1Q interacts with HSPA8 and LAMP-2A, which are core components of the CMA machinery. Knockdown of HSPA8 or LAMP-2A increased AF1Q protein levels, whereas overexpression showed the opposite effect. Using an amino acid deletion AF1Q mutation plasmid, we identified that AF1Q had a KFERQ-like motif which was recognized by HSPA8 for CMA-dependent proteolysis. In conclusion, we demonstrate for the first time that AF1Q can be degraded in lysosomes by CMA. - Highlights: • Chaperone-mediated autophagy (CMA) is involved in the degradation of AF1Q. • Macroautophagy does not contribute to the AF1Q degradation. • AF1Q has a KFERQ-like motif that is recognized by CMA core components.

  1. Evaluating the skill of seasonal weather forecasts in predicting aflatoxin contamination of groundnut in Senegal

    NASA Astrophysics Data System (ADS)

    Brak, B.; Challinor, A.

    2011-12-01

    Aflatoxins, a group of toxic secondary metabolites produced by some strains of a number of species within Aspergillus section Flavi, contaminate a range of crops grown at latitudes between 40N° and 40S° of the equator. Digestion of food products derived from aflatoxin-contaminated crops may result in acute and chronic health problems in human beings. Countries in sub-Saharan Africa in particular have seen large percentages of the human population exposed to aflatoxin. A recent study showed that over 98% of subjects in West Africa tested positive for aflatoxin biomarkers. According to other research, every year 250,000 people die from hepato-cellular carcinoma related causes due to aflatoxin ingestion in parts of West Africa. Strict aflatoxin levels set by importing countries in accordance with the WTO Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) also impair the value of agricultural trade. Over the last thirty years this has led to a reduction of African exports of groundnut by 19% despite the consumption of groundnut derived food products going up by 209%. The occurrence of aflatoxin on crops is strongly influenced by weather. Empirical studies in the US have shown that pre-harvest, aflatoxin contamination of groundnuts is induced by conditions of drought stress in combination with soil temperatures between 25°C and 31°C. Post-harvest, aflatoxin production of stored, Aspergillus-contaminated groundnuts is exacerbated in conditions where relative humidity is above 83%. The GLAM crop model was extended to include a soil temperature subroutine and subroutines containing pre- and post-harvest aflatoxin algorithms. The algorithms used to estimate aflatoxin contamination indices are based on findings from multiple empirical studies and the pre-harvest aflatoxin model has been validated for Australian conditions. Hence, there was sufficient scope to use GLAM with these algorithms to answer the foremost research question: Is the

  2. Effect of dietary acids on the formation of aflatoxin B2a as a means to detoxify aflatoxin B1.

    PubMed

    Rushing, Blake R; Selim, Mustafa I

    2016-09-01

    Aflatoxin B1 (AFB1) is a class 1 carcinogen and a common food contaminant worldwide with widely uncontrolled human exposure. The ability of organic acids to transform AFB1 into a known detoxified form, aflatoxin B2a (AFB2a), was investigated using high performance liquid chromatography-electrospray ionisation-time of flight mass spectrometry (HPLC/ESI/TOF/MS). The identity of the transformation product was confirmed by accurate mass measurement, chromatographic separation from other aflatoxins, H(1)-nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy. Of the weak acids tested, citric acid was found to be the most effective for AFB2a formation. At room temperature, 1 M citric acid was able to convert > 97% of AFB1 to AFB2a over 96 h of treatment. Up to 98% transformation was achieved by boiling AFB1 in the presence of citric acid for 20 min. AFB1 hydration after ingestion was explored by spiking AFB1 into simulated gastric fluid containing citric acid. Under these conditions, > 71% of AFB1 was hydrated to AFB2a and did not show any reversion to the parent compound after being transferred to a neutral solution. These results provide a basis for a practical and effective method for detoxification of AFB1 in contaminated foods.

  3. Present and future directions of translational research on aflatoxin and hepatocellular carcinoma. A review.

    PubMed

    Wogan, Gerald N; Kensler, Thomas W; Groopman, John D

    2012-01-01

    The aflatoxins were discovered in toxic peanut meal causing "turkey X" disease, which killed large numbers of turkey poults, ducklings and chicks in the UK in the early 1960s. Extracts of toxic feed induced the symptoms in experimental animals, and purified metabolites with properties identical to aflatoxins B(1) and G(1) (AFB(1) and AFG(1)) were isolated from Aspergillus flavus cultures. Structure elucidation of aflatoxin B(1) was accomplished and confirmed by total synthesis in 1963. AFB(1) is a potent liver carcinogen in rodents, non-human primates, fish and birds, operating through a genotoxic mechanism involving metabolic activation to an epoxide, formation of DNA adducts and, in humans, modification of the p53 gene. Aflatoxins are unique among environmental carcinogens, in that elucidation of their mechanisms of action combined with molecular epidemiology provides a foundation for quantitative risk assessment; extensive evidence confirms that contamination of the food supply by AFB(1) puts an exposed population at increased risk of developing hepatocellular carcinoma (HCC). Molecular biomarkers to quantify aflatoxin exposure in individuals were essential to link aflatoxin exposure with liver cancer risk. Biomarkers were validated in populations with high HCC incidence in China and The Gambia, West Africa; urinary AFB(1)-N (7)-Guanine excretion was linearly related to aflatoxin intake, and levels of aflatoxin-serum albumin adducts also reflected aflatoxin intake. Two major cohort studies employing aflatoxin biomarkers identified their causative role in HCC etiology. Results of a study in Shanghai men strongly support a causal relationship between HCC risk and the presence of biomarkers for aflatoxin and HBV infection, and also show that the two risk factors act synergistically. Subsequent cohort studies in Taiwan confirm these results. IARC classified aflatoxin as a Group 1 human carcinogen in 1993, based on sufficient evidence in humans and experimental

  4. Aflatoxin-induced biochemical changes in liver of mice and its mitigation by black tea extract.

    PubMed

    Jha, Anamika; Shah, Komal; Verma, Ramtej J

    2012-01-01

    Aflatoxin belongs to the class of naturally occurring mycotoxins, food contaminants having potent carcinogenicity. We have evaluated the ameliorative role of black tea extract on aflatoxin-induced biochemical changes in the liver of albino male mice. Adult male mice were orally administered with 750 and 1500 pg of aflatoxin in 0.2 mL olive oil/kg b.w./day for 30 days. Oral administration of aflatoxin caused, as compared with controls, significant, dose-dependent reduction in DNA, RNA, protein and glycogen contents; however, cholesterol content and phsphorylase activity were significantly increased. Black tea is one of the most potent antioxidants containing numerous bioactive phytonurtients having therapeutic applications. Aflatoxin-induced changes in the liver of mice were significantly ameliorated on co-treatment of black tea extract (2% infusion in water).

  5. AFS Estuaries Section - A Successful Partnership

    EPA Science Inventory

    The Estuaries Section of the American Fisheries Society offers travel awards to students in support of their attendance and presentations at the AFS meeting. Since 2007, the Southern Association of Marine Laboratories has partnered with the Estuaries Section to sponsor two stude...

  6. Topological ferrimagnetic behaviours of coordination polymers containing manganese(II) chains with mixed azide and carboxylate bridges and alternating F/AF/AF'/AF'/AF interactions.

    PubMed

    Wang, Yan-Qin; Liu, Hou-Ting; Qi, Yan; Gao, En-Qing

    2014-08-21

    Two Mn(ii) complexes with azide and a new zwitterionic tetracarboxylate ligand 1,2,4,5-tetrakis(4-carboxylatopyridinium-1-methylene)benzene (L(1)), {[Mn5(L(1))2(N3)8(OH)2]·12H2O}n () and {[Mn5(L(1))2(N3)8(H2O)2](ClO4)2·6H2O}n (), have been synthesized and characterized crystallographically and magnetically. and contain similar alternating chains constructed by azide and carboxylate bridges. The independent sets of bridges alternate in an ABCCB sequence between adjacent Mn(ii) ions: (EO-N3)2 double bridges (EO = end-on) (denoted as A), [(EO-N3)(OCO)2] triple bridges (denoted as B) and [(EO-N3)(OCO)] double bridges (denoted as C). The alternating chains are interlinked into 2D coordination networks by the tetrapyridinium spacers. Magnetic studies demonstrate that the magnetic coupling through the double EO azide bridges is ferromagnetic and that through mixed azide/carboxylate bridges is antiferromagnetic. The unprecedented F/AF/AF'/AF'/AF coupling sequence along the chain dictates an uncompensated ground spin state (S = 5/2 per Mn5 unit) and leads to one-dimensional topological ferrimagnetism, which features a minimum in the χT versus T plot.

  7. Stereoselectivity in Polyphenol Biosynthesis

    NASA Technical Reports Server (NTRS)

    Lewis, Norman G.; Davin, Laurence B.

    1992-01-01

    Stereoselectivity plays an important role in the late stages of phenyl-propanoid metabolism, affording lignins, lignans, and neolignans. Stereoselectivity is manifested during monolignol (glucoside) synthesis, e.g., where the geometry (E or Z) of the pendant double bond affects the specificity of UDPG:coniferyl alcohol glucosyltransferases in different species. Such findings are viewed to have important ramifications in monolignol transport and storage processes, with roles for both E- and Z-monolignols and their glucosides in lignin/lignan biosynthesis being envisaged. Stereoselectivity is also of great importance in enantiose-lective enzymatic processes affording optically active lignans. Thus, cell-free extracts from Forsythia species were demonstrated to synthesize the enantiomerically pure lignans, (-)-secoisolariciresinol, and (-)-pinoresinol, when NAD(P)H, H2O2 and E-coniferyl alcohol were added. Progress toward elucidating the enzymatic steps involved in such highly stereoselective processes is discussed. Also described are preliminary studies aimed at developing methodologies to determine the subcellular location of late-stage phenylpropanoid metabolites (e.g., coniferyl alcohol) and key enzymes thereof, in intact tissue or cells. This knowledge is essential if questions regarding lignin and lignan tissue specificity and regulation of these processes are to be deciphered.

  8. Parallels in lignin biosynthesis

    PubMed Central

    Weng, Jing-Ke; Banks, Jo Ann

    2008-01-01

    A hallmark of vascular plants is the development of a complex water-conducting system, which is physically reinforced by the heterogeneous aromatic polymer lignin. Syringyl lignin, a major building block of lignin, is often thought to be uniquely characteristic of angiosperms; however, it was demonstrated over fifty years ago that that syringyl lignin is found in another group of plants, known as the lycophytes, the ancestors of which diverged from all the other vascular plant lineages 400 million years ago.1 To determine the biochemical basis for this common biosynthetic ability, we isolated and characterized cytochrome P450-dependent monooxygenases (P450s) from the lycophyte Selaginella moellendorffii and compared them to the enzyme that is required for syringyl lignin synthesis in angiosperms. Our results showed that one of these P450s encodes an enzyme that is functionally analogous to but phylogenetically independent from its angiosperm counterpart. Here, we discuss the evolution of lignin biosynthesis in vascular plants and the role of Selaginella moellendorffii in plant comparative biology and genomics. PMID:19704782

  9. Survey of aflatoxin concentrations in wild bird seed purchased in Texas.

    PubMed

    Henke, S E; Gallardo, V C; Martinez, B; Balley, R

    2001-10-01

    The use of backyard feeders to attract avian wildlife is a common practice throughout the United States. However, feeding wildlife may create a problem due to aflatoxin, a harmful fungal metabolite, which can affect wildlife that are fed contaminated grain. Our study was initiated to determine if songbirds were being exposed to aflatoxin-contaminated feed throughout Texas. Bags of wild bird seed (n = 142) were purchased from grain cooperatives, grocery stores, and pet shops located in the panhandle, central, south, east, and west regions of Texas during spring and summer 1999. Aflatoxin concentrations in bird seed ranged from non-detectable to 2,780 micrograms/kg. Overall, 17% of samples had aflatoxin concentrations greater than 100 micrograms/kg, of which 83% contained corn as an ingredient. Retail establishment effects were noted in the southern and western regions of Texas, with average concentrations of aflatoxin greater from bags of bird seed purchased from grain cooperatives, followed by pet shops, then grocery stores. Regional differences in aflatoxin levels were not apparent from bags of seed purchased at pet shops: however, regional differences were noted in aflatoxin levels from seeds obtained at grocery stores and grain cooperatives. Average aflatoxin concentration from seed purchased at grocery stores was greatest in the panhandle region, followed by the remaining regions. Within grain cooperatives, the panhandle, south, and west regions of Texas exhibited higher levels of aflatoxin-contaminated bird seed than cooperatives within the east and central regions of Texas. Granivorous songbirds in Texas are exposed to aflatoxins at backyard feeders, which may be a significant morbidity and mortality factor.

  10. AF fixer: new incremental OPC method for optimizing assist feature

    NASA Astrophysics Data System (ADS)

    Jung, Sung-Gon; Kim, Sang-Wook; Suh, Sung-Soo; Kim, Young-Chang; Lee, Suk-Joo; Choi, Sung-Woon; Han, Woo-Sung; Moon, Joo-Tae; Barnes, Levi D.; Li, Xiaohai; Lugg, Robert M.; Lee, Sooryong; Koo, Kyoil; Do, Munhoe; Amoroso, Frank P.; Painter, Benjamin

    2008-05-01

    Due to shrinking design nodes and to some limitations of scanners, extreme off-axis illumination (OAI) required and its use and implementation of assist features (AF) to solve depth of focus (DOF) problems for isolated features and specific pitch regions is essential. But unfortunately, the strong periodic character of OAI illumination makes AF's print more easily. Present OPC flows generate AFs before OPC, which is also causes some AF printing problems. At present, mask manufacturers must downsize AF's below 30nm to solve this problem. This is challenging and increases mask cost. We report on an AF-fixer tool which is able to check AF printability and correct weak points with minimal cost in terms of DOF after OPC. We have devised an effective algorithm that removes printing AF's. It can not only search for the best non-printing AF condition to meet the DOF spec, but also reports uncorrectable spots, which could be marked as design errors. To limit correction times and to maximize DOF in full-chip correction, a process window (PW) model and incremental OPC method are applied. This AF fixer, which suggests optimum AF in only weak point region, solves AF printing problems economically and accurately.

  11. Integrated optic sensor for measuring aflatoxin-B1 in corn

    NASA Astrophysics Data System (ADS)

    Boiarski, Anthony A.; Busch, James R.; Brody, R. S.; Ridgway, Richard W.; Altman, Wolf P.; Golden, C.

    1996-03-01

    An integrated optic refractometer device was developed to perform a rapid one-step, homogeneous immunoassay. The device measures refractive index changes at the surface of a planar, singlemode, ion-exchange waveguide using difference interferometry. Anti-aflatoxin- B1 antibodies were attached to the waveguide surface to provide a bioselective coating for detecting and quantifying the aflatoxin-B1 antigen level in a sample. The detection limit of this small antigen must be determined using a competitive assay format. To determine feasibility of the competitive assay, we determined the biosensor response to a larger molecular weight competing antigen, namely HRP-labeled aflatoxin-B1. This labeled antigen will compete with unlabeled aflatoxin for binding sites on the sensor surface. Increased sample aflatoxin levels will result in a decreased time-dependent phase change of the helium-neon laser light beam. Phase change data were determined for various concentration levels of HRP-labeled aflatoxin- B1 antigen. The assay measurements were made over a 5-minute time period. Results indicated that a competitive assay is feasible. Future assay efforts should be able to demonstrate measurement of aflatoxin-B levels found in contaminated corn samples.

  12. The case for aflatoxins in the causal chain of gallbladder cancer.

    PubMed

    Foerster, Claudia; Koshiol, Jill; Guerrero, Ariel R; Kogan, Marcelo J; Ferreccio, Catterina

    2016-01-01

    Chronic aflatoxin exposure has long been related to hepatocellular carcinoma (HCC). Recently, its association with gallbladder cancer (GBC) was postulated. Here we present the data supporting this hypothesis in Chile, the country with the highest GBC mortality worldwide with age-standardized mortality rates (ASMR) of 10.3 in women and 5.04 in men. The highest GBC rates occur in Southern Chile (ASMR=18), characterized by: high Amerindian ancestry, associated with high bile acid synthesis and gallstones; high poverty and high cereal agriculture, both associated with aflatoxin exposure. Aflatoxins have been detected in imported and locally grown foods items. We estimated population dietary exposure ranging from 0.25 to 35.0 ng/kg-body weight/day. The only report on human exposure in Chile found significantly more aflatoxin biomarkers in GBC than in controls (Odds Ratio=13.0). The hypothesis of aflatoxin-GBC causal link in the Chilean population is supported by: genetically-determined rapid cholesterol excretion and high gallstones prevalence (49.4%); low prevalence of HCC (ASMR=4.9) and low HBV infection (0.15%) the main co-factor of aflatoxins in HCC risk. If the association between aflatoxins and GBC were confirmed, public health interventions based on food regulation could have a substantial public health impact.

  13. Global risk assessment of aflatoxins in maize and peanuts: are regulatory standards adequately protective?

    PubMed

    Wu, Felicia; Stacy, Shaina L; Kensler, Thomas W

    2013-09-01

    The aflatoxins are a group of fungal metabolites that contaminate a variety of staple crops, including maize and peanuts, and cause an array of acute and chronic human health effects. Aflatoxin B1 in particular is a potent liver carcinogen, and hepatocellular carcinoma (HCC) risk is multiplicatively higher for individuals exposed to both aflatoxin and chronic infection with hepatitis B virus (HBV). In this work, we sought to answer the question: do current aflatoxin regulatory standards around the world adequately protect human health? Depending upon the level of protection desired, the answer to this question varies. Currently, most nations have a maximum tolerable level of total aflatoxins in maize and peanuts ranging from 4 to 20ng/g. If the level of protection desired is that aflatoxin exposures would not increase lifetime HCC risk by more than 1 in 100,000 cases in the population, then most current regulatory standards are not adequately protective even if enforced, especially in low-income countries where large amounts of maize and peanuts are consumed and HBV prevalence is high. At the protection level of 1 in 10,000 lifetime HCC cases in the population, however, almost all aflatoxin regulations worldwide are adequately protective, with the exception of several nations in Africa and Latin America.

  14. Detoxification of Aflatoxin-Contaminated Maize by Neutral Electrolyzed Oxidizing Water.

    PubMed

    Jardon-Xicotencatl, Samantha; Díaz-Torres, Roberto; Marroquín-Cardona, Alicia; Villarreal-Barajas, Tania; Méndez-Albores, Abraham

    2015-10-23

    Aflatoxins, a group of extremely toxic mycotoxins produced by Aspergillus flavus, A. parasiticus and A. nomius, can occur as natural contaminants of certain agricultural commodities, particularly maize. These toxins have been shown to be hepatotoxic, carcinogenic, mutagenic and cause severe human and animal diseases. The effectiveness of neutral electrolyzed oxidizing water (NEW) on aflatoxin detoxification was investigated in HepG2 cells using several validation methodologies such as the 3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide assay, the induction of lipid peroxidation, the oxidative damage by means of glutathione modulation, the Ames test and the alkaline Comet assay. Our results showed that, after the aflatoxin-contaminated maize containing 360 ng/g was soaked in NEW (60 mg/L available chlorine, pH 7.01) during 15 min at room temperature, the aflatoxin content did not decrease as confirmed by the immunoaffinity column and ultra performance liquid chromatography methods. Aflatoxin fluorescence strength of detoxified samples was similar to untreated samples. However, aflatoxin-associated cytotoxicity and OPEN ACCESS Toxins 2015, 7 4295 genotoxicity effects were markedly reduced upon treatment. According to these results, NEW can be effectively used to detoxify aflatoxin-contaminated maize.

  15. Production of Aflatoxin on Wheat and Oats: Measurement with a Recording Densitometer

    PubMed Central

    Stubblefield, R. D.; Shotwell, O. L.; Hesseltine, C. W.; Smith, M. L.; Hall, H. H.

    1967-01-01

    A method has been developed for the production of aflatoxin by growing Aspergillus flavus NRRL 3145 on solid substrate wheat. Optimal yields of 900 μg of aflatoxin G1 and 900 μg of aflatoxin B1 per g of substrate were obtained in 4 to 5 days at 28 C. A study of aflatoxin production on hulls and groats of oats and on whole oats by A. flavus strains NRRL 2999, NRRL 3000, and NRRL 3145 revealed that aflatoxin was produced on all three substrates, although production was very slight on hulls. Strain NRRL 3145 grown on solid substrate groats produced the largest amounts of aflatoxin: 580 μg of B1 and 450 μg of G1 per g of substrate. A densitometric method for reading thin-layer chromatographic plates is described; this is more objective and more accurate than the visual methods previously used for the determination of all four aflatoxins. Images Fig. 1 PMID:6031432

  16. Inhibitory Activities of Alkyl Syringates and Related Compounds on Aflatoxin Production

    PubMed Central

    Furukawa, Tomohiro; Iimura, Kurin; Kimura, Taichi; Yamamoto, Toshiyoshi; Sakuda, Shohei

    2016-01-01

    Inhibitors of aflatoxin production of aflatoxigenic fungi are useful for preventing aflatoxin contamination in crops. As methyl syringate weakly inhibits aflatoxin production, aflatoxin production inhibitory activities of additional alkyl syringates with alkyl chains from ethyl to octyl were examined. Inhibitory activity toward aflatoxin production of Aspergillus flavus became stronger as the length of the alkyl chains on the esters became longer. Pentyl, hexyl, heptyl, and octyl syringates showed strong activity at 0.05 mM. Heptyl and octyl parabens, and octyl gallate also inhibited aflatoxin production as strongly as octyl syringate. Alkyl parabens and alkyl gallates inhibit the complex II activity of the mitochondrial respiration chain; thus, whether alkyl syringates inhibit complex II activity was examined. Inhibitory activities of alkyl syringates toward complex II also became stronger as the length of the alkyl chains increased. The complex II inhibitory activity of octyl syringate was comparable to that of octyl paraben and octyl gallate. These results suggest that alkyl syringates, alkyl parabens, and alkyl gallates, including commonly used food additives, are useful for aflatoxin control. PMID:27338472

  17. Susceptibility of strawberries, blackberries, and cherries to Aspergillus mold growth and aflatoxin production.

    PubMed

    Llewellyn, G C; Eadie, T; Dashek, W V

    1982-05-01

    The susceptibility of blackberries, cherries, and strawberries to Aspergillus growth and aflatoxin production has been examined. Three aflatoxigenic isolates of Aspergillus, A. flavus ATCC 15548 and NRRL 3251 as well as A. parasiticus NRRL 2999, were cultured on homogenates of the fruits for 14 days at 28 +/- 2 degrees C. Percent mycelial growth and spore infestation were determined each day with a calibrated grid. At day 14 each culture was frozen at -5 degrees C until aflatoxins were extracted with methylene chloride and water. Aflatoxins were separated by thin layer chromatography (TLC) with benzene-methanol-acetic acid (90 + 5 + 5). This extraction and solvent system provided satisfactory separations of the aflatoxins and was free of background interference on the TLC plates. Although all fruits served as substrates for both Aspergillus growth and aflatoxin production, cherries appeared to be a more favorable substrate than did blackberries, and the latter was more favorable than strawberries. Whereas A. flavus produced both B1 and G1 on all substrates, it yielded B2 and G2 only on cherries. Although A. parasiticus NRRL 2999 synthesized B1, B2, G1, and G2 on both blackberries and cherries, no aflatoxins were detected on strawberries. In contrast, A. flavus NRRL 3251 failed to produce detectable levels of aflatoxin on any substrate. All substrates supported both mycelial growth and subsequent sporulation with cherries greater than blackberries greater than strawberries.

  18. Assessment of Aflatoxin and Fumonisin Contamination of Maize in Western Kenya.

    PubMed

    Mutiga, S K; Hoffmann, V; Harvey, J W; Milgroom, M G; Nelson, R J

    2015-09-01

    We conducted a survey of aflatoxin and fumonisin in maize in western Kenya. In a regional survey of aflatoxin conducted in 2009 across three agroecological zones within three administrative regions, milled maize samples were collected from 985 patrons of 26 hammer mills. Aflatoxin contamination was detected in 49% of samples and was above the regulatory (10 ppb) in 15% of the samples overall; 65% of samples from a drought-prone area were over the limit. In a detailed survey in Bungoma County, we investigated aflatoxin and fumonisin contamination in four popular maize varieties at harvest and after 2 and 4 months of storage. We collected whole-grain samples from farmers' storage sheds and milled samples from patrons of local mills. Mean aflatoxin contamination was identical for storage sheds and mills at 2.3 ppb. In all, 41% of the samples from mills had detectable aflatoxin, with 4% over the regulatory limit, whereas 87% had detectable fumonisin, with 50% over the regulatory limit (1 ppm). Mean contamination levels did not change during storage. Maize varieties differed in fumonisin contamination, with the most popular varieties vulnerable to both mycotoxins and weevils, which are potential factors in exacerbating mycotoxin contamination. Mycotoxin surveillance is important not just in areas known previously for aflatoxin contamination and acute poisoning but also is needed in all maize-producing regions.

  19. Global Risk Assessment of Aflatoxins in Maize and Peanuts: Are Regulatory Standards Adequately Protective?

    PubMed Central

    Wu, Felicia

    2013-01-01

    The aflatoxins are a group of fungal metabolites that contaminate a variety of staple crops, including maize and peanuts, and cause an array of acute and chronic human health effects. Aflatoxin B1 in particular is a potent liver carcinogen, and hepatocellular carcinoma (HCC) risk is multiplicatively higher for individuals exposed to both aflatoxin and chronic infection with hepatitis B virus (HBV). In this work, we sought to answer the question: do current aflatoxin regulatory standards around the world adequately protect human health? Depending upon the level of protection desired, the answer to this question varies. Currently, most nations have a maximum tolerable level of total aflatoxins in maize and peanuts ranging from 4 to 20ng/g. If the level of protection desired is that aflatoxin exposures would not increase lifetime HCC risk by more than 1 in 100,000 cases in the population, then most current regulatory standards are not adequately protective even if enforced, especially in low-income countries where large amounts of maize and peanuts are consumed and HBV prevalence is high. At the protection level of 1 in 10,000 lifetime HCC cases in the population, however, almost all aflatoxin regulations worldwide are adequately protective, with the exception of several nations in Africa and Latin America. PMID:23761295

  20. Biotechnological advances for combating Aspergillus flavus and aflatoxin contamination in crops.

    PubMed

    Bhatnagar-Mathur, Pooja; Sunkara, Sowmini; Bhatnagar-Panwar, Madhurima; Waliyar, Farid; Sharma, Kiran Kumar

    2015-05-01

    Aflatoxins are toxic, carcinogenic, mutagenic, teratogenic and immunosuppressive byproducts of Aspergillus spp. that contaminate a wide range of crops such as maize, peanut, and cotton. Aflatoxin not only affects crop production but renders the produce unfit for consumption and harmful to human and livestock health, with stringent threshold limits of acceptability. In many crops, breeding for resistance is not a reliable option because of the limited availability of genotypes with durable resistance to Aspergillus. Understanding the fungal/crop/environment interactions involved in aflatoxin contamination is therefore essential in designing measures for its prevention and control. For a sustainable solution to aflatoxin contamination, research must be focused on identifying and improving knowledge of host-plant resistance factors to aflatoxin accumulation. Current advances in genetic transformation, proteomics, RNAi technology, and marker-assisted selection offer great potential in minimizing pre-harvest aflatoxin contamination in cultivated crop species. Moreover, developing effective phenotyping strategies for transgenic as well as precision breeding of resistance genes into commercial varieties is critical. While appropriate storage practices can generally minimize post-harvest aflatoxin contamination in crops, the use of biotechnology to interrupt the probability of pre-harvest infection and contamination has the potential to provide sustainable solution.

  1. Determination of aflatoxins in by-products of industrial processing of cocoa beans.

    PubMed

    Copetti, Marina V; Iamanaka, Beatriz T; Pereira, José Luiz; Lemes, Daniel P; Nakano, Felipe; Taniwaki, Marta H

    2012-01-01

    This study has examined the occurrence of aflatoxins in 168 samples of different fractions obtained during the processing of cocoa in manufacturing plants (shell, nibs, mass, butter, cake and powder) using an optimised methodology for cocoa by-products. The method validation was based on selectivity, linearity, limit of detection and recovery. The method was shown to be adequate for use in quantifying the contamination of cocoa by aflatoxins B(1), B(2), G(1) and G(2). Furthermore, the method was easier to use than other methods available in the literature. For aflatoxin extraction from cocoa samples, a methanol-water solution was used, and then immunoaffinity columns were employed for clean-up before the determination by high-performance liquid chromatography. A survey demonstrated a widespread occurrence of aflatoxins in cocoa by-products, although in general the levels of aflatoxins present in the fractions from industrial processing of cocoa were low. A maximum aflatoxin contamination of 13.3 ng g(-1) was found in a nib sample. The lowest contamination levels were found in cocoa butter. Continued monitoring of aflatoxins in cocoa by-products is nevertheless necessary because these toxins have a high toxicity to humans and cocoa is widely consumed by children through cocoa-containing products, like candies.

  2. Biosorption of B-aflatoxins Using Biomasses Obtained from Formosa Firethorn [Pyracantha koidzumii (Hayata) Rehder].

    PubMed

    Ramales-Valderrama, Rosa Adriana; Vázquez-Durán, Alma; Méndez-Albores, Abraham

    2016-07-13

    Mycotoxin adsorption onto biomaterials is considered as a promising alternative for decontamination without harmful chemicals. In this research, the adsorption of B-aflatoxins (AFB₁ and AFB₂) using Pyracantha koidzumii biomasses (leaves, berries and the mixture of leaves/berries) from aqueous solutions was explored. The biosorbent was used at 0.5% (w/v) in samples spiked with 100 ng/mL of B-aflatoxin standards and incubated at 40 °C for up to 24 h. A standard biosorption methodology was employed and aflatoxins were quantified by an immunoaffinity column and UPLC methodologies. The biosorbent-aflatoxin interaction mechanism was investigated from a combination of zeta potential (ζ), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The highest aflatoxin uptakes were 86% and 82% at 6 h using leaves and the mixture of leaves/berries biomasses, respectively. A moderate biosorption of 46% was attained when using berries biomass. From kinetic studies, the biosorption process is described using the first order adsorption model. Evidence from FTIR spectra suggests the participation of hydroxyl, amine, carboxyl, amide, phosphate and ketone groups in the biosorption and the mechanism was proposed to be dominated by the electrostatic interaction between the negatively charged functional groups and the positively charged aflatoxin molecules. Biosorption by P. koidzumii biomasses has been demonstrated to be an alternative to conventional systems for B-aflatoxins removal.

  3. Detoxification of Aflatoxin-Contaminated Maize by Neutral Electrolyzed Oxidizing Water

    PubMed Central

    Jardon-Xicotencatl, Samantha; Díaz-Torres, Roberto; Marroquín-Cardona, Alicia; Villarreal-Barajas, Tania; Méndez-Albores, Abraham

    2015-01-01

    Aflatoxins, a group of extremely toxic mycotoxins produced by Aspergillus flavus, A. parasiticus and A. nomius, can occur as natural contaminants of certain agricultural commodities, particularly maize. These toxins have been shown to be hepatotoxic, carcinogenic, mutagenic and cause severe human and animal diseases. The effectiveness of neutral electrolyzed oxidizing water (NEW) on aflatoxin detoxification was investigated in HepG2 cells using several validation methodologies such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the induction of lipid peroxidation, the oxidative damage by means of glutathione modulation, the Ames test and the alkaline Comet assay. Our results showed that, after the aflatoxin-contaminated maize containing 360 ng/g was soaked in NEW (60 mg/L available chlorine, pH 7.01) during 15 min at room temperature, the aflatoxin content did not decrease as confirmed by the immunoaffinity column and ultra performance liquid chromatography methods. Aflatoxin fluorescence strength of detoxified samples was similar to untreated samples. However, aflatoxin-associated cytotoxicity and genotoxicity effects were markedly reduced upon treatment. According to these results, NEW can be effectively used to detoxify aflatoxin-contaminated maize. PMID:26512692

  4. Occupational exposure to Aspergillus and aflatoxins among food-grain workers in India

    PubMed Central

    Malik, Abida; Ali, Sana; Shahid, Mohd; Bhargava, Rakesh

    2014-01-01

    Background: Aflatoxins are a metabolite of Aspergillus molds and are widespread in the natural environment. Workers who handle food grains are at increased risk of exposure to aflatoxins and subsequently certain respiratory conditions. In India, more than half of the employed population is engaged in some type of agricultural work, yet little known about the respiratory problems as a result of exposure to aflatoxins among workers who handle food grains in India. Objectives: The aim of this study was to determine the risk of occupational exposure to aflatoxins in food-grain workers compared to workers who are not occupationally exposed to food grains. Methods: Bronchoalveolar lavage (BAL) and serum samples from 46 food-grain workers and 44 non-food-grain workers were analyzed for the presence of aflatoxins. Microscopy and culture of BAL samples were performed to detect Aspergillus species. Results: Aflatoxins were detected in 32.6% of the food-grain workers and 9.1% of non food grain workers (P<0.01). A significant difference was also found in BAL culture for Aspergillus (P<0.01) between the two groups. About 47.8% of the food-grain workers and 11.4% of non-food-grain workers had chronic respiratory symptoms. Conclusion: Occupational exposure to aflatoxins in food-grain workers was found to be associated with the increased presence of respiratory symptoms. PMID:25000106

  5. Biosorption of B-aflatoxins Using Biomasses Obtained from Formosa Firethorn [Pyracantha koidzumii (Hayata) Rehder

    PubMed Central

    Ramales-Valderrama, Rosa Adriana; Vázquez-Durán, Alma; Méndez-Albores, Abraham

    2016-01-01

    Mycotoxin adsorption onto biomaterials is considered as a promising alternative for decontamination without harmful chemicals. In this research, the adsorption of B-aflatoxins (AFB1 and AFB2) using Pyracantha koidzumii biomasses (leaves, berries and the mixture of leaves/berries) from aqueous solutions was explored. The biosorbent was used at 0.5% (w/v) in samples spiked with 100 ng/mL of B-aflatoxin standards and incubated at 40 °C for up to 24 h. A standard biosorption methodology was employed and aflatoxins were quantified by an immunoaffinity column and UPLC methodologies. The biosorbent-aflatoxin interaction mechanism was investigated from a combination of zeta potential (ζ), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The highest aflatoxin uptakes were 86% and 82% at 6 h using leaves and the mixture of leaves/berries biomasses, respectively. A moderate biosorption of 46% was attained when using berries biomass. From kinetic studies, the biosorption process is described using the first order adsorption model. Evidence from FTIR spectra suggests the participation of hydroxyl, amine, carboxyl, amide, phosphate and ketone groups in the biosorption and the mechanism was proposed to be dominated by the electrostatic interaction between the negatively charged functional groups and the positively charged aflatoxin molecules. Biosorption by P. koidzumii biomasses has been demonstrated to be an alternative to conventional systems for B-aflatoxins removal. PMID:27420096

  6. Interventions targeting child undernutrition in developing countries may be undermined by dietary exposure to aflatoxin.

    PubMed

    Watson, Sinead; Gong, Yun Yun; Routledge, Michael

    2017-06-13

    Child undernutrition, a form of malnutrition, is a major public health burden in developing countries. Supplementation interventions targeting the major micronutrient deficiencies have only reduced the burden of child undernutrition to a certain extent, indicating that there are other underlying determinants that need to be addressed. Aflatoxin exposure, which is also highly prevalent in developing countries, may be considered an aggravating factor for child undernutrition. Increasing evidence suggests that aflatoxin exposure can occur in any stage of life, including in utero through a trans-placental pathway and in early childhood (through contaminated weaning food and family food). Early life exposure to aflatoxin is associated with adverse effects on low birth weight, stunting, immune suppression, and the liver function damage. The mechanisms underlying impaired growth and aflatoxin exposure are still unclear but intestinal function damage, reduced immune function, and alteration in the insulin-like growth factor axis caused by the liver damage are the suggested hypotheses. Given the fact that both aflatoxin and child undernutrition are common in sub-Saharan Africa, effective interventions aimed at reducing undernutrition cannot be satisfactorily achieved until the interactive relationship between aflatoxin and child undernutrition is clearly understood, and an aflatoxin mitigation strategy takes effect in those vulnerable mothers and children.

  7. Boric acid: a potential chemoprotective agent against aflatoxin b1 toxicity in human blood

    PubMed Central

    Geyikoglu, Fatime

    2010-01-01

    Aflatoxin B1 is the most potent pulmonary and hepatic carcinogen. Since the eradication of Aflatoxin B1 contamination in agricultural products has been difficult, the use of natural or synthetic free radical scavengers could be a potential chemopreventive strategy. Boric acid is the major component of industry and its antioxidant role has recently been reported. The present study assessed, for the first time, the effectiveness of boric acid following exposure to Aflatoxin B1 on human whole blood cultures. The biochemical characterizations of glutathione and some enzymes have been carried out in erythrocytes. Alterations in malondialdehyde level were determined as an index of oxidative stress. The sister-chromatid exchange and micronucleus tests were performed to assess DNA damages in lymphocytes. Aflatoxin B1 treatment significantly reduced the activities of antioxidants by increasing malondialdehyde level (30.53 and 51.43%) of blood, whereas, the boric acid led to an increased resistance of DNA to oxidative damage induced by Aflatoxin B1 in comparison with control values (P < 0.05). In conclusion, the support of boric acid was especially useful in Aflatoxin-toxicated blood. Thus the risk on tissue targeting of Aflatoxin B1 could be reduced ensuring early recovery from its toxicity. PMID:20431944

  8. Microfluidic Pumps Containing Teflon [Trademark] AF Diaphragms

    NASA Technical Reports Server (NTRS)

    Willis, Peter; White, Victor; Grunthaner, Frank; Ikeda, Mike; Mathies, Richard A.

    2009-01-01

    Microfluidic pumps and valves based on pneumatically actuated diaphragms made of Teflon AF polymers are being developed for incorporation into laboratory-on-a-chip devices that must perform well over temperature ranges wider than those of prior diaphragm-based microfluidic pumps and valves. Other potential applications include implanted biomedical microfluidic devices, wherein the biocompatability of Teflon AF polymers would be highly advantageous. These pumps and valves have been demonstrated to function stably after cycling through temperatures from -125 to 120 C. These pumps and valves are intended to be successors to similar prior pumps and valves containing diaphragms made of polydimethylsiloxane (PDMS) [commonly known as silicone rubber]. The PDMS-containing valves ae designed to function stably only within the temperature range from 5 to 80 C. Undesirably, PDMS membranes are somwehat porous and retain water. PDMS is especially unsuitable for use at temperatures below 0 C because the formation of ice crystals increases porosity and introduces microshear.

  9. Electrochemical immunochip sensor for aflatoxin M1 detection.

    PubMed

    Parker, Charlie O; Lanyon, Yvonne H; Manning, Mary; Arrigan, Damien W M; Tothill, Ibtisam E

    2009-07-01

    An investigation into the fabrication, electrochemical characterization, and development of a microelectrode array (MEA) immunosensor for aflatoxin M(1) is presented in this paper. Gold MEAs (consisting of 35 microsquare electrodes with 20 microm x 20 microm dimensions and edge-to-edge spacing of 200 microm) together with on-chip reference and counter electrodes were fabricated using standard photolithographic methods. The MEAs were then characterized by cyclic voltammetry, and the behavior of the on-chip electrodes were evaluated. The microarray sensors were assessed for their applicability to the development of an immunosensor for the analysis of aflatoxin M(1) directly in milk samples. Following the sensor surface silanization, antibodies were immobilized by cross-linking with 1,4-phenylene diisothiocyanate (PDITC). Surface characterization was conducted by electrochemistry, fluorescence microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). A competitive enzyme linked immunosorbent assay (ELISA) assay format was developed on the microarray electrode surface using the 3,3,5',5'-tetramethylbenzidine dihyrochloride (TMB)/H(2)O(2) electrochemical detection scheme with horseradish peroxidase (HRP) as the enzyme label. The performance of the assay and the microarray sensor were characterized in pure buffer conditions before applying to the milk samples. With the use of this approach, the detection limit for aflatoxin M(1) in milk was estimated to be 8 ng L(-1), with a dynamic detection range of 10-100 ng L(-1), which meets present legislative limits of 50 ng L(-1). The milk interference with the sensor surface was also found to be minimal. These devices show high potential for development of a range of new applications which have previously only been detected using elaborate instrumentation.

  10. [The aflatoxins and liver cancer in Guangxi, China].

    PubMed

    Yu, S Z

    1992-05-01

    The AFB1 intake and the AFM1 excretion of 81 households in 10 villages, Guanxi were investigated using the ELISA method. The results showed that there was positive correlation between PLC mortality and AFB1 intake from corn and peanut oil, but not from rice. The results of stepwise regression showed that main factors were AFB1 intake of males, AFM1 excretion of females and consumption of corn. The results showed that aflatoxins were correlated with mortality rates of liver cancer. Further investigation needs to be carried out in case-control and cohort studies.

  11. Stability of aflatoxin B-1 and ochratoxin A in brewing.

    PubMed

    Chu, F S; Chang, C C; Ashoor, S H; Prentice, N

    1975-03-01

    The stability of aflatoxin B-1 and ochratoxin A in brewing was investigated by adding the purified toxins to the raw materials at 1 and 10 mug/g levels during mashing in a conventional micro-brewing process. The results indicate that both toxins are stable to heat and are insensitive to cooker mash treatment. Both mycotoxins were partially removed in the mashing and brewing processes. About 14 to 18% and 27 to 28% of the added toxins were found in the final beers brewed from starting materials containing 1 and 10 mug, respectively, of either toxin per g. The possible route of transmission of mycotoxins into beer is discussed.

  12. Potential economic losses to the US corn industry from aflatoxin contamination.

    PubMed

    Mitchell, Nicole J; Bowers, Erin; Hurburgh, Charles; Wu, Felicia

    2016-01-01

    Mycotoxins, toxins produced by fungi that colonise food crops, can pose a heavy economic burden to the US corn industry. In terms of economic burden, aflatoxins are the most problematic mycotoxins in US agriculture. Estimates of their market impacts are important in determining the benefits of implementing mitigation strategies within the US corn industry, and the value of strategies to mitigate mycotoxin problems. Additionally, climate change may cause increases in aflatoxin contamination in corn, greatly affecting the economy of the US Midwest and all sectors in the United States and worldwide that rely upon its corn production. We propose two separate models for estimating the potential market loss to the corn industry from aflatoxin contamination, in the case of potential near-future climate scenarios (based on aflatoxin levels in Midwest corn in warm summers in the last decade). One model uses the probability of acceptance based on operating characteristic (OC) curves for aflatoxin sampling and testing, while the other employs partial equilibrium economic analysis, assuming no Type 1 or Type 2 errors, to estimate losses due to proportions of lots above the US Food and Drug Administration (USFDA) aflatoxin action levels. We estimate that aflatoxin contamination could cause losses to the corn industry ranging from US$52.1 million to US$1.68 billion annually in the United States, if climate change causes more regular aflatoxin contamination in the Corn Belt as was experienced in years such as 2012. The wide range represents the natural variability in aflatoxin contamination from year to year in US corn, with higher losses representative of warmer years.

  13. Population structure and aflatoxin production by Aspergillus Sect. Flavi from maize in Nigeria and Ghana.

    PubMed

    Perrone, Giancarlo; Haidukowski, Miriam; Stea, Gaetano; Epifani, Filomena; Bandyopadhyay, Ranajit; Leslie, John F; Logrieco, Antonio

    2014-08-01

    Aflatoxins are highly toxic carcinogens that contaminate crops worldwide. Previous studies conducted in Nigeria and Ghana found high concentrations of aflatoxins in pre- and post-harvest maize. However, little information is available on the population structure of Aspergillus Sect. Flavi in West Africa. We determined the incidence of Aspergillus Sect. Flavi and the level of aflatoxin contamination in 91 maize samples from farms and markets in Nigeria and Ghana. Aspergillus spp. were recovered from 61/91 maize samples and aflatoxins B1 and/or B2 occurred in 36/91 samples. Three samples from the farms also contained aflatoxin G1 and/or G2. Farm samples were more highly contaminated than were samples from the market, in terms of both the percentage of the samples contaminated and the level of mycotoxin contamination. One-hundred-and-thirty-five strains representative of the 1163 strains collected were identified by using a multilocus sequence analysis of portions of the genes encoding calmodulin, β-tubulin and actin, and evaluated for aflatoxin production. Of the 135 strains, there were 110 - Aspergillus flavus, 20 - Aspergillus tamarii, 2 - Aspergillus wentii, 2 - Aspergillus flavofurcatus, and 1 - Aspergillus parvisclerotigenus. Twenty-five of the A. flavus strains and the A. parvisclerotigenus strain were the only strains that produced aflatoxins. The higher contamination of the farm than the market samples suggests that the aflatoxin exposure of rural farmers is even higher than previously estimated based on reported contamination of market samples. The relative infrequency of the A. flavus SBG strains, producing small sclerotia and high levels of both aflatoxins (B and G), suggests that long-term chronic exposure to this mycotoxin are a much higher health risk in West Africa than is the acute toxicity due to very highly contaminated maize in east Africa.

  14. Potential economic losses to the USA corn industry from aflatoxin contamination

    PubMed Central

    Mitchell, N.J.; Bowers, E.; Hurburgh, C.; Wu, F.

    2016-01-01

    Mycotoxins, toxins produced by fungi that colonize food crops, can pose a heavy economic burden to the United States corn industry. In terms of economic burden, aflatoxins are the most problematic mycotoxins in US agriculture. Estimates of their market impacts are important in determining the benefits of implementing mitigation strategies within the US corn industry, and the value of strategies to mitigate mycotoxin problems. Additionally, climate change may cause increases in aflatoxin contamination in corn, greatly affecting the economy of the US Midwest and all sectors in the US and worldwide that rely upon its corn production. We propose two separate models for estimating the potential market loss to the corn industry from aflatoxin contamination, in the case of potential near-future climate scenarios (based on aflatoxin levels in Midwest corn in warm summers in the last decade). One model uses probability of acceptance based on operating characteristic (OC) curves for aflatoxin sampling and testing, while the other employs partial equilibrium economic analysis, assuming no Type 1 or Type 2 errors, to estimate losses due to proportions of lots above the US Food and Drug Administration (FDA) aflatoxin action levels. We estimate that aflatoxin contamination could cause losses to the corn industry ranging from $52.1 million to $1.68 billion annually in the United States, if climate change causes more regular aflatoxin contamination in the Corn Belt as was experienced in years such as 2012. The wide range represents the natural variability in aflatoxin contamination from year to year in US corn, with higher losses representative of warmer years. PMID:26807606

  15. [Adsorption of aflatoxin on montmorillonite modified by low-molecular-weight humic acids].

    PubMed

    Yao, Jia-Jia; Kang, Fu-Xing; Gao, Yan-Zheng

    2012-03-01

    The adsorption of a typical biogenic toxin aflatoxin B1 on montmorillonite modified by low-molecular-weight humic acids (M(r) < 3 500) was investigated. The montmorillonite rapidly adsorbed the aflatoxin B1 until amounting to the maximal capacity, and then the adsorbed aflatoxin B1 slowly released into solution and reached the sorption equilibrium state after 12 h. The sorption isotherm of aflatoxin B1 by montmorillonite could be well described by Langmiur model, while the sorption isotherm by humic acid-modified montmorillonite was well fitted by using the Freundlich model. The modification of the montmorillonite with humic acids obviously enhanced its adsorption capacity for aflatoxin B1, and the amounts of aflatoxin adsorbed by modified montmorillonite were obviously higher than those by montmorillonite. The sorption enhancement by humic acid modification was attributed to (1) the enlarged adsorption sites which owed to the surface collapse of crystal layers induced by organic acids, and (2) the binding of aflatoxin with the humic acid sorbed on mineral surface. In addition, the adsorption amounts of aflatoxin by montmorillonite and modified montmorillonite increased with the increase of pH values in solution, and more significant enhancement was observed for the latter than the former, which attributed to the release of humic acids from the modified montmorillonite with the high pH values in solution. This indicates that increasing the pH values resulted in the enhanced hydrophilic property and the release of the organic acids presented in modified montmorillonite, and more sorption sites were available for aflatoxin on the modified montmorillonite. Results of this work would strengthen our understanding of the behavior and fate of biological contaminants in the environment.

  16. Assessment of hot peppers for aflatoxin and mold proliferation during storage.

    PubMed

    Iqbal, Qumer; Amjad, Muhammad; Asi, Muhammad Rafique; Ariño, Agustin

    2011-05-01

    Aflatoxin contamination and mold proliferation in three hot pepper hybrids (Sky Red, Maha, and Wonder King) were studied during 5 months of storage at three temperatures (20, 25, and 30°C) and under different packaging conditions (low-density polyethylene bags and jute bags). The presence of aflatoxins in hot pepper samples was determined by high-performance liquid chromatography with a UV-Vis detector. Sampling for analysis of aflatoxins, total mold counts, and Aspergillus counts was carried out at 0, 50, 100, and 150 days of storage. Hot peppers packed in jute bags were more susceptible to aflatoxin contamination than those packed in polyethylene bags; aflatoxin concentrations were 75% higher in peppers stored in jute bags. The effect of storage temperature resulted in aflatoxin concentrations that were 61% higher in hot peppers stored at 25 and 30°C than in those stored at 20°C. Of the three pepper hybrids, Wonder King was more susceptible to aflatoxin contamination, with a maximum of 1.50 μg/kg when packed in jute bags and stored at 25°C for 150 days. However, no sample exceeded the maximum permitted level for total aflatoxins in spices established by European Union regulations (10 μg/kg). Total mold counts and Aspergillus counts increased with storage duration, but all counts were significantly lower in peppers stored in polyethylene bags. A gradual increase in temperature during prolonged storage of hot peppers in combination with aeration may be the main reasons for increases in fungal biomass and Aspergillus proliferation with the subsequent aflatoxin production.

  17. Enzyme-linked immunosorbent assay for determination of aflatoxin M1 based on magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Atanasova, M. K.; Ivanova, N. V.; Godjevargova, T. I.

    2017-02-01

    A sensitive enzyme immunoassay with magnetic nanoparticles (Method A) for the quantitative determination of aflatoxin M1 in milk was developed. This immunoassay was based on the immobilization of monoclonal antibody (mAb) on the modified magnetic nanoparticles (MNPs-NH2). It was observed that for each mg of the MNPs, 25 µg of antibody was immobilized. Both aflatoxin M1 in the sample and aflatoxin M1-BSA-peroxidase conjugate competed for the immobilized antibody. The proposed Method A was compared with other method (B). The Method B was based on the immobilization of aflatoxin M1-BSA conjugate on the MNPs-NH2, which competed with the aflatoxin M1 in the sample for binding to the added mAb. The binding of mAb to the aflatoxin M1-BSA-MNPs-NH2 was detected using a target secondary IgG-peroxidase antibody. The analytical characteristics of the two methods were compared. Real milk samples were investigated for present of aflatoxin M1. Two methods were based on the use of MNPs as a solid support for covalently immunoreagents immobilization. A comfortable separation of bound and free fraction of the tracer can be performed only through a simple collection of the MNPs by a permanent magnet. The application of MNPs helps to eliminate non-specific binding and to retain higher activity of bound biomolecules. The development of a MNPs-based ELISA for determination of aflatoxin M1 has a great potential to supersede the traditional ELISA for aflatoxin M1 diagnosis.

  18. Determination of Aflatoxin B1 in Smokeless Tobacco Products by Use of UHPLC-MS/MS.

    PubMed

    Zitomer, Nicholas; Rybak, Michael E; Li, Zhong; Walters, Matthew J; Holman, Matthew R

    2015-10-21

    This work developed a UHPLC-MS/MS method for the detection and quantitation of aflatoxins in smokeless tobacco products, which was then used to determine aflatoxin B1 concentrations in 32 smokeless tobacco products commercially available in the United States. Smokeless tobacco products were dried, milled, and amended with (13)C17-labeled internal standards, extracted in water/methanol solution in the presence of a surfactant, isolated through use of immunoaffinity column chromatography, and reconstituted in mobile phase prior to UHPLC-MS/MS analysis. The method was capable of baseline separation of aflatoxins B1, B2, G1, and G2 in a 2.5 min run by use of a fused core C18 column and a water/methanol gradient. MS/MS transition (m/z) 313.3 → 241.2 was used for aflatoxin B1 quantitation, with 313.3 → 285.1 used for confirmation. The limit of detection (LOD) for aflatoxin B1 was 0.007 parts per billion (ppb). Method imprecision for aflatoxin B1 (expressed as coefficient of variation) ranged from 5.5 to 9.4%. Spike recoveries were 105-111%. Aflatoxin B1 concentrations in the smokeless tobacco products analyzed ranged from Aflatoxin B1 was most frequently detected in dry snuffs and chews, whereas all moist snuff products tested were below LOD. The amounts of aflatoxin B1 detected were low relative to the 20 ppb regulatory limit established by the U.S. Food and Drug Administration for foods and feeds.

  19. Auxin biosynthesis and storage forms.

    PubMed

    Korasick, David A; Enders, Tara A; Strader, Lucia C

    2013-06-01

    The plant hormone auxin drives plant growth and morphogenesis. The levels and distribution of the active auxin indole-3-acetic acid (IAA) are tightly controlled through synthesis, inactivation, and transport. Many auxin precursors and modified auxin forms, used to regulate auxin homeostasis, have been identified; however, very little is known about the integration of multiple auxin biosynthesis and inactivation pathways. This review discusses the many ways auxin levels are regulated through biosynthesis, storage forms, and inactivation, and the potential roles modified auxins play in regulating the bioactive pool of auxin to affect plant growth and development.

  20. Auxin biosynthesis and storage forms

    PubMed Central

    Strader, Lucia C.

    2013-01-01

    The plant hormone auxin drives plant growth and morphogenesis. The levels and distribution of the active auxin indole-3-acetic acid (IAA) are tightly controlled through synthesis, inactivation, and transport. Many auxin precursors and modified auxin forms, used to regulate auxin homeostasis, have been identified; however, very little is known about the integration of multiple auxin biosynthesis and inactivation pathways. This review discusses the many ways auxin levels are regulated through biosynthesis, storage forms, and inactivation, and the potential roles modified auxins play in regulating the bioactive pool of auxin to affect plant growth and development. PMID:23580748

  1. [Applications of molecular biology techniques for the control of aflatoxin contamination].

    PubMed

    Sanchis, V

    1993-02-01

    Aflatoxins are mycotoxins produced by species of Aspergillus flavus group. These toxins have received increased attention from the food industry and the general public because they shown a high toxicity against humans and animal. Different methods are applying to control the aflatoxin contamination. But these conventional methods do not seem to resolve the problem. So, new methods using techniques in biotechnology are now being developed: a) Inhibit the biosynthetic and secretory process responsible for aflatoxin contamination. b) Using biocompetitive agents that replace aflatoxigenic strains with non aflatoxigenic strains in the field. c) Using genetic engineering techniques to incorporate antifungal genes into specific plant species.

  2. Aflatoxin contamination in soybeans: role of proteinase inhibitors, zinc availability, and seed coat integrity.

    PubMed Central

    Stössel, P

    1986-01-01

    Soybean trypsin inhibitors are thought to ward off pathogens. Studies with aflatoxigenic strains of Aspergillus flavus and A. parasiticus, frequent soybean contaminants, revealed that trypsin inhibitors do not affect the growth of these fungi and aflatoxin production. Further, the availability of zinc, an essential mineral for aflatoxin synthesis that was thought to explain increased aflatoxin accumulation in cooked compared with raw soybeans, was shown to decrease upon cooking. Seed coat integrity, ensuring limited access and a low moisture content, is responsible for the slow colonization of the seed by A. flavus. Images PMID:3089160

  3. Use of gamma irradiation to prevent aflatoxin B 1 production in smoked dried fish

    NASA Astrophysics Data System (ADS)

    Ogbadu, G. H.

    Smoked dried fish bought from the Nigerian market was inoculated with spores of barAspergillus flavus (U.I. 81) and irradiated with doses of 0.625, 1.25, 2.50 and 5.00 KGy gamma irradiation. The effect of aflatoxin B 1 production on subsequent incubation for 8 days as stationary cultures was measured. The amount of aflatoxin B 1 produced was found to decrease with increased gamma irradiation dose levels. While the non-irradiated control produced significantly (at 1% level) greater amounts of aflatoxin B 1 as compared to the treated cultures.

  4. Carryover of aflatoxin B/sub 1/ in contaminated substrate corn into Nigerian native beer

    SciTech Connect

    Okoye, Z.S.C.

    1986-10-01

    Aflatoxins, the toxic secondary metabolites of Aspergillus flavus and Asp. parasiticus, constitute a serious food contamination problem in Nigeria and have been detected in the blood of healthy rural blood donors and primary liver cancer patients from the Guinea savannah region where traditionally brewed cereal beer is popular. A recent survey of traditional breweries in the Jos metropolis has shown a high incidence of aflatoxin B/sub 1/ contamination of their products. The purpose of this study was to assess the efficiency of the traditional brewing in destroying aflatoxins in mould-infected substrate grains.

  5. Aflatoxin contamination of red chili pepper from Bolivia and Peru, countries with high gallbladder cancer incidence rates.

    PubMed

    Asai, Takao; Tsuchiya, Yasuo; Okano, Kiyoshi; Piscoya, Alejandro; Nishi, Carlos Yoshito; Ikoma, Toshikazu; Oyama, Tomizo; Ikegami, Kikuo; Yamamoto, Masaharu

    2012-01-01

    Chilean red chili peppers contaminated with aflatoxins were reported in a previous study. If the development of gallbladder cancer (GBC) in Chile is associated with a high level of consumption of aflatoxin-contaminated red chili peppers, such peppers from other countries having a high GBC incidence rate may also be contaminated with aflatoxins. We aimed to determine whether this might be the case for red chili peppers from Bolivia and Peru. A total of 7 samples (3 from Bolivia, 4 from Peru) and 3 controls (2 from China, 1 from Japan) were evaluated. Aflatoxins were extracted with acetonitrile:water (9:1, v/v) and eluted through an immuno-affinity column. The concentrations of aflatoxins B1, B2, G1, and G2 were measured using high-performance liquid chromatography (HPLC), and then the detected aflatoxins were identified using HPLC-mass spectrometry. In some but not all of the samples from Bolivia and Peru, aflatoxin B1 or aflatoxins B1 and B2 were detected. In particular, aflatoxin B1 or total aflatoxin concentrations in a Bolivian samples were above the maximum levels for aflatoxins in spices proposed by the European Commission. Red chili peppers from Bolivia and Peru consumed by populations having high GBC incidence rates would appear to be contaminated with aflatoxins. These data suggest the possibility that a high level of consumption of aflatoxin-contaminated red chili peppers is related to the development of GBC, and the association between the two should be confirmed by a case-control study.

  6. Aflatoxin contamination of pearl millet during field and storage conditions with reference to stage of grain maturation and insect damage.

    PubMed

    Raghavender, C R; Reddy, B N; Shobharani, G

    2007-12-01

    Aflatoxin contamination in five varieties of pearl millet (ICMH-451, ICMP-50I, ICTP-8203, WCC-75 and ICMV-155) was studied from field and storage conditions in three districts of Andhra Pradesh State, India and the inter-relationships between various parameters such as stage of grain maturation in the field and insect pest infestation in storage in relation to aflatoxin production were evaluated. Aflatoxin contamination was more frequent in the seed samples collected from the fields during rainy season than winter season. All major aflatoxins were isolated from one or the other varieties of pearl millet, whereas aflatoxin G2 was not commonly observed in the seed samples collected during winter. Among all the varieties tested, ICMH-451 was vulnerable to aflatoxin contamination whereas ICMV-155 was the least susceptible variety. The higher amount of aflatoxins was observed in the matured seed samples followed by pre-matured and milky stage. Among all the toxins reported in the field, aflatoxin B1 was found in higher concentration (185 (μg/kg) followed by B2 (105 μg/kg). The four major types of aflatoxins with higher levels (35, 40, 140, 190 μg/kg of G1, G2, B2, B1 were reported in the rainy season seed samples after six months of storage, whereas aflatoxin G1 was not observed in any variety of stored seed sample from winter. Statistical analysis revealed that the aflatoxin incidence in relation to different parameters studied was significantly different for each factor. The relationship between aflatoxin contamination and insect damaged-grain clearly indicated that the seed samples with 16-40% of insect damage contained higher amounts of aflatoxins (758 μg/kg).

  7. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins.

    PubMed

    Zhang, Liyuan; Ma, Qiugang; Ma, Shanshan; Zhang, Jianyun; Jia, Ru; Ji, Cheng; Zhao, Lihong

    2016-12-22

    Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize), M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize), M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060). The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB₁ (M0) exhibited a decreasing tendency in average daily gain (ADG) and total superoxide dismutase (T-SOD) activity in serum, and T-SOD and glutathione peroxidase (GSH-Px) activities in the liver significantly decreased along with the appearance of AFB₁ and AFM₁ compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks (p > 0.05), significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive.

  8. Ameliorating Effects of Bacillus subtilis ANSB060 on Growth Performance, Antioxidant Functions, and Aflatoxin Residues in Ducks Fed Diets Contaminated with Aflatoxins

    PubMed Central

    Zhang, Liyuan; Ma, Qiugang; Ma, Shanshan; Zhang, Jianyun; Jia, Ru; Ji, Cheng; Zhao, Lihong

    2016-01-01

    Bacillus subtilis ANSB060 isolated from fish gut is very effective in detoxifying aflatoxins in feed and feed ingredients. The purpose of this research was to investigate the effects of B. subtilis ANSB060 on growth performance, body antioxidant functions, and aflatoxin residues in ducks fed moldy maize naturally contaminated with aflatoxins. A total of 1500 18-d-old male Cherry Valley ducks with similar body weight were randomly assigned to five treatments with six replicates of 50 ducks per repeat. The experiment design consisted of five dietary treatments labeled as C0 (basal diet containing 60% normal maize), M0 (basal diet containing 60% moldy maize contaminated with aflatoxins substituted for normal maize), M500, M1000, and M2000 (M0 +500, 1000 or 2000 g/t aflatoxin biodegradation preparation mainly consisted of B. subtilis ANSB060). The results showed that ducks fed 22.44 ± 2.46 μg/kg of AFB1 (M0) exhibited a decreasing tendency in average daily gain (ADG) and total superoxide dismutase (T-SOD) activity in serum, and T-SOD and glutathione peroxidase (GSH-Px) activities in the liver significantly decreased along with the appearance of AFB1 and AFM1 compared with those in Group C0. The supplementation of B. subtilis ANSB060 into aflatoxin-contaminated diets increased the ADG of ducks (p > 0.05), significantly improved antioxidant enzyme activities, and reduced aflatoxin accumulation in duck liver. In conclusion, Bacillus subtilis ANSB060 in diets showed an ameliorating effect to duck aflatoxicosis and may be a promising feed additive. PMID:28025501

  9. Calcium montmorillonite clay reduces AFB1 and FB1 biomarkers in rats exposed to single and co-exposures of aflatoxin and fumonisin

    PubMed Central

    Mitchell, Nicole J.; Xue, Kathy S.; Lin, Shuhan; Marroquin-Cardona, Alicia; Brown, Kristal A.; Elmore, Sarah E.; Tang, Lili; Romoser, Amelia; Gelderblom, Wentzel C. A.; Wang, Jia-Sheng; Phillips, Timothy D.

    2014-01-01

    Aflatoxins (AFs) and fumonisins (FBs) can co-contaminate foodstuffs and have been associated with hepatocellular and esophageal carcinomas in humans at high risk for exposure. One strategy to reduce exposure (and toxicity) from contaminated foodstuffs is the dietary inclusion of a montmorillonite clay (UPSN) that binds AFs and FBs in the GI tract. In this study, the binding capacity of UPSN was evaluated for AFB1, FB1 and a combination thereof in Fischer-344 rats. Rats were pre-treated with different dietary levels of UPSN (0.25 or 2%) for 1 week. Rats were gavaged with a single dose of either 0.125 mg AFB1 or 25 mg FB1/kg b.w. and a combination thereof in the presence and absence of an aqueous solution of UPSN. The kinetics of mycotoxin excretion were monitored by analyzing serum AFB1-albumin, urinary AF (AFM1), and FB1 biomarkers over a period of 72 hr. UPSN decreased AFM1 excretion by 88-97%, indicating highly effective binding. FB1 excretion was reduced, to a lesser extent, ranging between 45 to 85%. When in combination, both AFB1 and FB1 binding occurred, but capacity was decreased by almost half. In the absence of UPSN, the combined AFB1 and FB1 treatment decreased the urinary biomarkers by 67 and 45% respectively, but increased levels of AFB1-albumin, presumably by modulating its cytochrome metabolism. UPSN significantly reduced bioavailability of both AFB1 and FB1 when in combination; suggesting that it can be utilized to reduce levels below their respective thresholds for affecting adverse biological effects. PMID:24193864

  10. Further evidence supporting the concurrent influence of aflatoxin and manganese

    SciTech Connect

    Katzen, J.S.; Llewellyn, G.C.

    1987-04-01

    Trace elements, including manganese may afford protection from deleterious effects of aflatoxin. Young male Fischer rats received ip injections of aflatoxin B1 (AFB1) in dimethyl sulfoxide (DMSO), 1 mg/kg, 2 mg/kg or 4 mg/kg. Control groups received DMSO ip or no injection. All animals were intubated with 3 microCi of (/sup 54/Mn)-MnCl/sub 2/ 12 hr post-injection. Sacrifice occurred 72 hr after gavage of the radiolabel. All tested levels of AFB1 affected the loss of total body radioactivity. This response was observed within 12 hr when toxin-treated groups excreted almost 4 times more counts than controls. From 12-36 hr following radiolabel administration, AFB1 appeared to enhance excretion; by 72 hr, toxin-treated animals (especially those receiving higher doses) appeared to conserve the metal. Aflatoxicosis manifested itself through reduced body weight gain. The data provide support evidence that Mn and AFB1 biointeract.

  11. Aflatoxin M1 in human breast milk in southeastern Turkey.

    PubMed

    Kılıç Altun, Serap; Gürbüz, Semra; Ayağ, Emin

    2016-12-28

    This study was performed to determine aflatoxin M1 (AFM1) in human breast milk samples collected in Şanlıurfa, located in Southeastern region of Turkey, and to investigate a possible correlation between AFM1 occurrence (frequency and levels) and sampling seasons. Human breast milk samples collected in December 2014 and in June 2015 from a total of 74 nursing women, both outpatient and inpatient volunteers in hospitals located in Şanlıurfa, Turkey, were analyzed using competitive enzyme-linked immunosorbent assay (ELISA) for the presence of AFM1. AFM1 was detected in 66 (89.2%) out of 74 samples at an average concentration of 19.0 ± 13.0 ng/l (min.-max., 9.6-80 ng/l). There was a statistically significant difference between December and June concerning AFM1 levels (p < 0.05). Further detailed studies will be needed to determine the main sources of aflatoxins in food, to establish protection strategies against maternal and infant exposure to these mycotoxins.

  12. Cost-effectiveness of lowering the aflatoxin tolerance level.

    PubMed

    Dichter, C R; Weinstein, M C

    1984-06-01

    The cost-effectiveness of adopting aflatoxin tolerance levels of 15, 10 and 5 ppb for peanuts and peanut products was assessed. Estimates of the annual cost to manufacturers of monitoring and controlling peanut aflatoxin levels at the current 20-ppb action level, and estimates of the projected increase in costs of establishing lower tolerances were elicited from producers by questionnaire. Exposures to peanut products were derived from the HANES I survey and from peanut production statistics. The risk of liver cancer at each tolerance level was estimated using both epidemiological and extrapolated experimental data assuming that exposure would be reduced in direct proportion to the decrease in the tolerance. It was found that the 15-ppb tolerance would cost $60,000 per cancer death averted (range $20,000-$1,700,000) and is therefore relatively cost-effective. The marginal costs per life saved for both the 10-ppb and 5-ppb levels were found to be $1.7 million (range $0.6 million-$11.4 million) and $1.6 million (range +0.6 million-$31.1 million), respectively. Conclusions on the optimal regulatory approach should be guided by comparisons of these figures with corresponding cost-effectiveness ratios for alternative regulatory uses of national resources in the interests of public health.

  13. Aflatoxin B1 binding to sorbents in bovine ruminal fluid.

    PubMed

    Spotti, M; Fracchiolla, M L; Arioli, F; Caloni, F; Pompa, G

    2005-08-01

    A recent approach to the problem of contamination of agricultural products by aflatoxin B(1) (AFB(1)) is to add non-nutritional adsorbents to animal diets in order to sequester ingested aflatoxins. We conducted in vitro experiments to develop a rapid and cheap model using ruminal fluid to assess the ability of sorbent materials to bind AFB(1). Seven sorbents (hydrated sodium calcium aluminosilicate; clinoptilolite; zeolite; two types of bentonite; sepiolite; and PHIL 75), commonly added to bovine diets were incubated in water and ruminal fluid in the presence of AFB(1). Hydrated sodium calcium aluminosilicate, sepiolite and one of the bentonites bound 100% of the AFB(1) in the presence of both ruminal fluid and water; clinoptilolite bound about 80% of AFB(1) in both liquids; whereas the affinities for the mycotoxin of zeolite (50%) and the other sample of bentonite (60%) in water seem to be increased by about 40% in ruminal fluid incubations. PHIL 75 had the poorest binding ability: about 30% in water and 45% in ruminal fluid. In view of the differences in toxin binding in water and ruminal fluid, it is preferable to use the ruminal fluid model for the in vitro pre-screening of sorbent materials potentially useful as adjuvants to ruminant feeds.

  14. Transcription factors in alkaloid biosynthesis.

    PubMed

    Yamada, Yasuyuki; Sato, Fumihiko

    2013-01-01

    Higher plants produce a large variety of low-molecular weight secondary compounds. Among them, nitrogen-containing alkaloids are the most biologically active and are often used pharmaceutically. Whereas alkaloid chemistry has been intensively investigated, alkaloid biosynthesis, including the relevant biosynthetic enzymes, genes and their regulation, and especially transcription factors, is largely unknown, as only a limited number of plant species produce certain types of alkaloids and they are difficult to study. Recently, however, several groups have succeeded in isolating the transcription factors that are involved in the biosynthesis of several types of alkaloids, including bHLH, ERF, and WRKY. Most of them show Jasmonate (JA) responsiveness, which suggests that the JA signaling cascade plays an important role in alkaloid biosynthesis. Here, we summarize the types and functions of transcription factors that have been isolated in alkaloid biosynthesis, and characterize their similarities and differences compared to those in other secondary metabolite pathways, such as phenylpropanoid and terpenoid biosyntheses. The evolution of this biosynthetic pathway and regulatory network, as well as the application of these transcription factors to metabolic engineering, is discussed.

  15. Genome-wide transcriptome analysis reveals that a pleiotropic antibiotic regulator, AfsS, modulates nutritional stress response in Streptomyces coelicolor A3(2)

    PubMed Central

    Lian, Wei; Jayapal, Karthik P; Charaniya, Salim; Mehra, Sarika; Glod, Frank; Kyung, Yun-Seung; Sherman, David H; Hu, Wei-Shou

    2008-01-01

    Background A small "sigma-like" protein, AfsS, pleiotropically regulates antibiotic biosynthesis in Streptomyces coelicolor. Overexpression of afsS in S. coelicolor and certain related species causes antibiotic stimulatory effects in the host organism. Although recent studies have uncovered some of the upstream events activating this gene, the mechanisms through which this signal is relayed downstream leading to the eventual induction of antibiotic pathways remain unclear. Results In this study, we employed whole-genome DNA microarrays and quantitative PCRs to examine the transcriptome of an afsS disruption mutant that is completely deficient in the production of actinorhodin, a major S. coelicolor antibiotic. The production of undecylprodigiosin, another prominent antibiotic, was, however, perturbed only marginally in the mutant. Principal component analysis of temporal gene expression profiles identified two major gene classes each exhibiting a distinct coordinate differential expression pattern. Surprisingly, nearly 70% of the >117 differentially expressed genes were conspicuously associated with nutrient starvation response, particularly those of phosphate, nitrogen and sulfate. Furthermore, expression profiles of some transcriptional regulators including at least two sigma factors were perturbed in the mutant. In almost every case, the effect of afsS disruption was not observed until the onset of stationary phase. Conclusion Our data suggests a comprehensive role for S. coelicolor AfsS as a master regulator of both antibiotic synthesis and nutritional stress response, reminiscent of alternative sigma factors found in several bacteria. PMID:18230178

  16. A fully automated method for simultaneous determination of aflatoxins and ochratoxin A in dried fruits by pressurized liquid extraction and online solid-phase extraction cleanup coupled to ultra-high-pressure liquid chromatography-tandem mass spectrometry.

    PubMed

    Campone, Luca; Piccinelli, Anna Lisa; Celano, Rita; Russo, Mariateresa; Valdés, Alberto; Ibáñez, Clara; Rastrelli, Luca

    2015-04-01

    According to current demands and future perspectives in food safety, this study reports a fast and fully automated analytical method for the simultaneous analysis of the mycotoxins with high toxicity and wide spread, aflatoxins (AFs) and ochratoxin A (OTA) in dried fruits, a high-risk foodstuff. The method is based on pressurized liquid extraction (PLE), with aqueous methanol (30%) at 110 °C, of the slurried dried fruit and online solid-phase extraction (online SPE) cleanup of the PLE extracts with a C18 cartridge. The purified sample was directly analysed by ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for sensitive and selective determination of AFs and OTA. The proposed analytical procedure was validated for different dried fruits (vine fruit, fig and apricot), providing method detection and quantification limits much lower than the AFs and OTA maximum levels imposed by EU regulation in dried fruit for direct human consumption. Also, recoveries (83-103%) and repeatability (RSD < 8, n = 3) meet the performance criteria required by EU regulation for the determination of the levels of mycotoxins in foodstuffs. The main advantage of the proposed method is full automation of the whole analytical procedure that reduces the time and cost of the analysis, sample manipulation and solvent consumption, enabling high-throughput analysis and highly accurate and precise results.

  17. (-)-Menthol biosynthesis and molecular genetics

    NASA Astrophysics Data System (ADS)

    Croteau, Rodney B.; Davis, Edward M.; Ringer, Kerry L.; Wildung, Mark R.

    2005-12-01

    (-)-Menthol is the most familiar of the monoterpenes as both a pure natural product and as the principal and characteristic constituent of the essential oil of peppermint ( Mentha x piperita). In this paper, we review the biosynthesis and molecular genetics of (-)-menthol production in peppermint. In Mentha species, essential oil biosynthesis and storage is restricted to the peltate glandular trichomes (oil glands) on the aerial surfaces of the plant. A mechanical method for the isolation of metabolically functional oil glands, has provided a system for precursor feeding studies to elucidate pathway steps, as well as a highly enriched source of the relevant biosynthetic enzymes and of their corresponding transcripts with which cDNA libraries have been constructed to permit cloning and characterization of key structural genes. The biosynthesis of (-)-menthol from primary metabolism requires eight enzymatic steps, and involves the formation and subsequent cyclization of the universal monoterpene precursor geranyl diphosphate to the parent olefin (-)-(4 S)-limonene as the first committed reaction of the sequence. Following hydroxylation at C3, a series of four redox transformations and an isomerization occur in a general “allylic oxidation-conjugate reduction” scheme that installs three chiral centers on the substituted cyclohexanoid ring to yield (-)-(1 R, 3 R, 4 S)-menthol. The properties of each enzyme and gene of menthol biosynthesis are described, as are their probable evolutionary origins in primary metabolism. The organization of menthol biosynthesis is complex in involving four subcellular compartments, and regulation of the pathway appears to reside largely at the level of gene expression. Genetic engineering to up-regulate a flux-limiting step and down-regulate a side route reaction has led to improvement in the composition and yield of peppermint oil.

  18. Detection of aflatoxin-contaminated grain by three granivorous bird species.

    PubMed

    Perez, M; Henke, S E; Fedynich, A M

    2001-04-01

    Supplemental feeding of game species and the use of backyard feeders to attract avian wildlife are common practices throughout the United States. However, these activities may expose wildlife to aflatoxins. We tested the hypothesis that wild birds would avoid consuming aflatoxin-contaminated feed. Individual northern bobwhites (Colinus virginianus), white-winged doves (Zenaida asiatica), and green jays (Cyanocorax yncas) were presented with feeders that had four compartments, which contained milo that was contaminated with aflatoxin levels of 0, 100, 500, and 1,000 microg/kg, respectively. Feed remaining was weighed at 6, 12, 18, 24, 36, 48, 60, and 72 hr after the initiation of the trial. White-winged doves and northern bobwhites did not avoid contaminated feed. However, green jays selected against aflatoxin-tainted grain. Because white-winged doves and northern bobwhites did not avoid contaminated feed, the risk of exposure to this potentially hazardous toxin exists for these species.

  19. Evaluation of ELISA screening test for detecting aflatoxin in biogenic dust samples

    SciTech Connect

    Durant, J.T.

    1996-05-01

    Aflatoxin is a carcinogenic chemical that is sometimes produced when agricultural commodities are infested by the fungi Aspergillus flavus and A. Parasiticus. Aflatoxin has been found to be present in air samples taken around persons handling materials likely to be contaminated. The purpose of this investigation was to demonstrate the feasibility of using an Enzyme Linked Immunosorbent Assay (ELISA) test kit that was developed to screen for aflatoxin in bulk agricultural commodities, to an air sample. Samples were taken from two environments likely to be contaminated with aflatoxin, a dairy farm feed mixing operation and a peanut bagging operation. The dust collected from these environments was considered to be biogenic, in that it originated primarily from biological materials.

  20. Blocking aflatoxins in corn by using non-toxigenic strains of Aspergillus flavus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are over 500 previously reported mycotoxins. However, only a few have been identified as important for food safety, including aflatoxins, fumonisins, cyclopiazonic acid (CPA), trichothecenes, zearalenone, ochratoxins, and patulin. Mycotoxins contaminate plant materials, causing acute and ch...

  1. Aflatoxins in Food Products in Iran: a Review of the Literature

    PubMed Central

    Hedayati, Mohammad Taghi; Mahdavi Omran, Saeid; Soleymani, Abbas; Taghizadeh Armaki, Mojtaba

    2016-01-01

    Context Mycotoxins are secondary metabolites produced by certain toxigenic fungi and the most of them are aflatoxins, fumonisins, trichothecenes, ochratoxin A, patulin, and zearalenone. Evidence Acquisition In consideration of the consumption of certain farm products for animal feed and the prevalence of toxigenic fungi and mycotoxins in food, the present study was performed to evaluate this situation in Iran with a review of the literature using search engines. All published articles were selected using Iran Medex, Magiran, PubMed NCBI, and Google Scholar. Results Aflatoxins have been found in many food products in Iran. Conclusions It is necessary to detect aflatoxins in foods and food products as early as possible, before they enter human or animal bodies. There is a high consumption of milk and dairy products in Iran, and the proper management of animal foods can help to decrease the aflatoxins in milk. PMID:27679702

  2. A rapid, sensitive and economic method for the detection, quantification and confirmation of aflatoxins.

    PubMed

    Majerus, P; Zakaria, Z

    1992-10-01

    A rapid, sensitive and economic method for the detection, quantification and confirmation of aflatoxins is described. Aflatoxins B1, B2, G1, and G2, are extracted by methanol/water (85 + 15) and partitioned into methylene dichloride. The methylene dichloride solution is cleaned up on a polypropylene column, filled with 0.5 g silica gel 60. The aflatoxins are eluted with chloroform-acetone (90:10) and are detected using bidirectional thin-layer chromatography (TLC) with aluminium silica gel foil. The mean recovery of aflatoxins B1, B2, G1, and G2 in corn samples was 73, 78, 80, and 64%, respectively; the limit of detection was 0.5 micrograms/kg. The results can also be confirmed by derivative formation using trifluoroacetic acid on the TLC plate. The method has been applied to a wide range of foods with good results.

  3. [Aflatoxins in food: tests of decontamination of peanut cakes by ionizing treatment].

    PubMed

    Diop, Y M; Ndiaye, B; Diouf, A; Fall, M; Thiam, A; Ciss, M; Hasselmann, C; Ba, D

    1999-01-01

    The efficacy of ionising treatment for decontaminating peanut cakes was tested. The influence of cakes water content and the effect of ionisation dose rate were studied. The results obtained after a reverse phase liquid chromatographic determination of B1, B2, G1 and G2 aflatoxins have revealed an important contamination of the peanut cakes (up to 1000 ppb of total aflatoxin's contents). After ionising treatment at 25 kGy, the aflatoxins degradation in peanut cake's was less important in dried samples (about 5-10% at 0.55 water activity: aw) than in the humid ones (40-60% degradation at 0.95 water activity). At this dose, any indicative difference of the degradation rate of aflatoxins, with regard to the ionising process was observed. The efficacy of ionising treatment for decontaminating peanut cakes could probably be improved, however the economic interest of such process as alternative of the treatment with ammonia is questionable.

  4. Effects of Trace Metals on the Production of Aflatoxins by Aspergillus parasiticus

    PubMed Central

    Marsh, Paul B.; Simpson, Marion E.; Trucksess, Mary W.

    1975-01-01

    Certain metals added as salts to a defined basal culture medium influenced the level of aflatoxin production by Aspergillus parasiticus in the low microgramsper-milliliter range of the added metal. In many cases no change or a relatively small change in mat weight and final pH of the medium accompanied this effect. With zinc at added levels of 0 to 10 μg/ml in the medium, aflatoxin increased 30-to 1,000-fold with increasing of zinc, whereas mat weight increased less than threefold. At 25 μg of added zinc per ml, aflatoxin decreased, but mat weight did not. At an added level of 25 μg or less of the metal per ml, salts of iron, manganese, copper, cadmium, trivalent chromium, silver, and mercury partly or completely inhibited aflatoxin production, without influencing mat weight. PMID:238471

  5. Aflatoxin Production of Species and Strains of the Aspergillus flavus Group Isolated from Field Crops

    PubMed Central

    Schroeder, H. W.; Boller, R. A.

    1973-01-01

    Peanuts, cottonseed, rice, and sorghum from Texas were sampled over a 3-year period. To insure adequate isolation of alfatoxin-producing species of fungi, low-quality lots were sampled at a rate greater than their respective proportional representation. Aflatoxins were found each year in peanut and cottonseed and were found in 2 of 3 years in rice and sorghum. Aflatoxins were detected in all four crops. The Aspergillus flavus group was much more prevalent in peanut and rice than in cottonseed and sorghum. Of the isolates of the A. flavus group, 96% from peanuts, 79% from cottonseed, 49% from sorghum, and 35% from rice produced aflatoxins. The average toxin production of isolates from rice was much less than that from peanuts, cottonseed, or sorghum. More than 90% of all isolates of the A. flavus group were identified as the species A. flavus. A. parasiticus was isolated from all four crops. Only A. parasiticus produced aflatoxin G. PMID:4197766

  6. Coaxially electrospun PVDF-Teflon AF and Teflon AF-PVDF core-sheath nanofiber mats with superhydrophobic properties.

    PubMed

    Muthiah, Palanikkumaran; Hsu, Shu-Hau; Sigmund, Wolfgang

    2010-08-03

    This work reports the coaxial electrospinning of poly(vinylidene fluoride) (PVDF)-Teflon amorphous fluoropolymer (AF) and Teflon AF-PVDF core-sheath nanofiber mats yielding superhydrophobic properties. The coaxial electrospinning configuration allows for the electrospinning of Teflon AF, a nonelectrospinnable polymer, with the help of an electrospinnable PVDF polymer. PVDF-Teflon AF and Teflon AF-PVDF core-sheath fibers have been found to a have mean fiber diameter ranging from 400 nm to less than 100 nm. TEM micrographs exhibit a typical core-sheath fiber structure for these fibers, where the sheath fiber coats the core fiber almost thoroughly. Water contact angle measurements by sessile drop method on these core-sheath nanofiber mats exhibited superhydrophobic characteristics with contact angles close to or higher than 150 degrees. Surprisingly, PVDF-Teflon AF and Teflon AF-PVDF nanofiber mat surface properties were dominated by the fiber dimensions and less influenced by the type of sheath polymer. This suggests that highly fluorinated polymer Teflon AF does not advance the hydrophobicity beyond what surface physics and slightly fluorinated polymer PVDF can achieve. It is concluded that PVDF-Teflon AF and Teflon AF-PVDF core-sheath electrospun nanofiber mats may be used in lithium (Li)-air batteries.

  7. Natural occurrence of aflatoxins in peanuts and peanut butter from Bulawayo, Zimbabwe.

    PubMed

    Mupunga, I; Lebelo, S L; Mngqawa, P; Rheeder, J P; Katerere, D R

    2014-10-01

    Mycotoxins are toxic secondary metabolites produced by filamentous fungi that may contaminate food and pose a health risk, especially in developing countries, where there is a lack of food security and quality is subsumed by food insufficiency. Aflatoxins are the most toxic known mycotoxins and are a significant risk factor for liver and kidney cancer, teratogenicity, undernutrition, and micronutrient malabsorption in both humans and animals. The main aim of the study was to determine the extent of fungal and aflatoxin contamination in peanuts and peanut butter being sold in both the formal and informal markets in Bulawayo, Zimbabwe. Eighteen peanut samples and 11 peanut butter samples were purchased from retail shops and the informal market. Fungal contamination was determined using standard mycology culture methods, while aflatoxin contamination was determined using high-performance liquid chromatography-fluorescence detection. Four of the six peanut samples tested for fungal contamination were infected with Aspergillus flavus/parasiticus, ranging from 3 to 20% of the kernels examined, while 27% (3 of 11) of the peanut butter samples were infected with A. flavus/parasiticus. Ninety-one percent (10 of 11) of the peanut butter samples were contaminated with aflatoxins (mean, 75.66 ng/g, and range, 6.1 to 247 ng/g), and aflatoxin B1 was the most prevalent (mean, 51.0 ng/g, and range, 3.7 to 191 ng/g). Three of the 18 peanut samples were contaminated with aflatoxins (range, 6.6 to 622 ng/g). The commercial peanut butter samples had very high aflatoxin levels, and manufacturers should be sensitized to the detrimental effects of aflatoxins and measures to reduce contamination.

  8. Reduction of aflatoxin production by Aspergillus flavus and Aspergillus parasiticus in interaction with Streptomyces.

    PubMed

    Verheecke, C; Liboz, T; Anson, P; Diaz, R; Mathieu, F

    2015-05-01

    The aim of this study is to investigate aflatoxin gene expression during Streptomyces-Aspergillus interaction. Aflatoxins are carcinogenic compounds produced mainly by Aspergillus flavus and Aspergillus parasiticus. A previous study has shown that Streptomyces-A. flavus interaction can reduce aflatoxin content in vitro. Here, we first validated this same effect in the interaction with A. parasiticus. Moreover, we showed that growth reduction and aflatoxin content were correlated in A. parasiticus but not in A. flavus. Secondly, we investigated the mechanisms of action by reverse-transcriptase quantitative PCR. As microbial interaction can lead to variations in expression of household genes, the most stable [act1, βtub (and cox5 for A. parasiticus)] were chosen using geNorm software. To shed light on the mechanisms involved, we studied during the interaction the expression of five genes (aflD, aflM, aflP, aflR and aflS). Overall, the results of aflatoxin gene expression showed that Streptomyces repressed gene expression to a greater level in A. parasiticus than in A. flavus. Expression of aflR and aflS was generally repressed in both Aspergillus species. Expression of aflM was repressed and was correlated with aflatoxin B1 content. The results suggest that aflM expression could be a potential aflatoxin indicator in Streptomyces species interactions. Therefore, we demonstrate that Streptomyces can reduce aflatoxin production by both Aspergillus species and that this effect can be correlated with the repression of aflM expression.

  9. Household dietary exposure to aflatoxins from maize and maize products in Kenya.

    PubMed

    Kilonzo, Robert M; Imungi, Jasper K; Muiru, William M; Lamuka, Peter O; Njage, Patrick M Kamau

    2014-01-01

    Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analysed for aflatoxin contamination. The samples were quantitatively analysed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modelled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18 and 480 μg kg⁻¹, 20% of muthokoi at between 12 and 123 μg kg⁻¹, and 35% of maize meal at between 6 and 30 μg kg⁻¹. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg⁻¹ body weight day⁻¹, while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 and 27 ± 154 ng kg⁻¹ body weight day⁻¹ respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.

  10. Chlorophyllin intervention reduces aflatoxin-DNA adducts in individuals at high risk for liver cancer.

    PubMed

    Egner, P A; Wang, J B; Zhu, Y R; Zhang, B C; Wu, Y; Zhang, Q N; Qian, G S; Kuang, S Y; Gange, S J; Jacobson, L P; Helzlsouer, K J; Bailey, G S; Groopman, J D; Kensler, T W

    2001-12-04

    Residents of Qidong, People's Republic of China, are at high risk for development of hepatocellular carcinoma, in part from consumption of foods contaminated with aflatoxins. Chlorophyllin, a mixture of semisynthetic, water-soluble derivatives of chlorophyll that is used as a food colorant and over-the-counter medicine, has been shown to be an effective inhibitor of aflatoxin hepatocarcinogenesis in animal models by blocking carcinogen bioavailability. In a randomized, double-blind, placebo-controlled chemoprevention trial, we tested whether chlorophyllin could alter the disposition of aflatoxin. One hundred and eighty healthy adults from Qidong were randomly assigned to ingest 100 mg of chlorophyllin or a placebo three times a day for 4 months. The primary endpoint was modulation of levels of aflatoxin-N(7)-guanine adducts in urine samples collected 3 months into the intervention measured by using sequential immunoaffinity chromatography and liquid chromatography-electrospray mass spectrometry. This aflatoxin-DNA adduct excretion product serves as a biomarker of the biologically effective dose of aflatoxin, and elevated levels are associated with increased risk of liver cancer. Adherence to the study protocol was outstanding, and no adverse events were reported. Aflatoxin-N(7)-guanine could be detected in 105 of 169 available samples. Chlorophyllin consumption at each meal led to an overall 55% reduction (P = 0.036) in median urinary levels of this aflatoxin biomarker compared with those taking placebo. Thus, prophylactic interventions with chlorophyllin or supplementation of diets with foods rich in chlorophylls may represent practical means to prevent the development of hepatocellular carcinoma or other environmentally induced cancers.

  11. Sampling hazelnuts for aflatoxin: effect of sample size and accept/reject limit on reducing the risk of misclassifying lots.

    PubMed

    Ozay, Guner; Seyhan, Ferda; Yilmaz, Aysun; Whitaker, Thomas B; Slate, Andrew B; Giesbrecht, Francis G

    2007-01-01

    About 100 countries have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely among regulating countries, the Codex Committee on Food Additives and Contaminants began work in 2004 to harmonize aflatoxin limits and sampling plans for aflatoxin in almonds, pistachios, hazelnuts, and Brazil nuts. Studies were developed to measure the uncertainty and distribution among replicated sample aflatoxin test results taken from aflatoxin-contaminated treenut lots. The uncertainty and distribution information is used to develop a model that can evaluate the performance (risk of misclassifying lots) of aflatoxin sampling plan designs for treenuts. Once the performance of aflatoxin sampling plans can be predicted, they can be designed to reduce the risks of misclassifying lots traded in either the domestic or export markets. A method was developed to evaluate the performance of sampling plans designed to detect aflatoxin in hazelnuts lots. Twenty hazelnut lots with varying levels of contamination were sampled according to an experimental protocol where 16 test samples were taken from each lot. The observed aflatoxin distribution among the 16 aflatoxin sample test results was compared to lognormal, compound gamma, and negative binomial distributions. The negative binomial distribution was selected to model aflatoxin distribution among sample test results because it gave acceptable fits to observed distributions among sample test results taken from a wide range of lot concentrations. Using the negative binomial distribution, computer models were developed to calculate operating characteristic curves for specific aflatoxin sampling plan designs. The effect of sample size and accept/reject limits on the chances of rejecting good lots (sellers' risk) and accepting bad lots (buyers' risk) was demonstrated for various sampling plan designs.

  12. Effect of dietary resveratrol in ameliorating aflatoxin B1-induced changes in broiler birds.

    PubMed

    Sridhar, M; Suganthi, R U; Thammiaha, V

    2015-12-01

    Consumption of aflatoxin B1 (AFB1) contaminated feed by poultry affects the health of broiler birds causing severe economic losses. The use of phytochemicals is a safe, effective, alternative and practical approach to combat the toxic effect of AF in broilers. Resveratrol, a polyphenol derived from red grapes, berries and peanuts, exerts anti-inflammatory, antioxidant and immunomodulatory effects. Our study was aimed at evaluating the possible protective effects of resveratrol against the adverse effects of AFB1 in broiler birds. A feeding trial of 42 days of duration was undertaken in a completely randomized design with five dietary treatments: G1-AFB1(1.0 ppm); G2-CTR (basal diet alone); G3-AFB1(1.0 ppm)+Resv 0.5%; G4-AFB1(1.0 ppm)+Resv 1%; and G5-Resv 1%. Gain in body weight (BWG) and feed intake (FI) was observed to be highest (p < 0.05) in the AFB1 birds followed by the control group. Feed conversion ratio was lowest in G2-CTR birds and failed to record any significant variation (p > 0.05) between groups as well as within groups. Birds fed resveratrol at both 0.5% and 1.0% levels in combination with AFB1 as well as alone along with basal diet had lower BWG and FI between the fourth and fifth week and also at the fifth week (p < 0.05). No variation (p > 0.05) was obtained in the FCR of AFB1 and resveratrol group of broiler birds. AFB1 feeding significantly increased the activities of aspartate-(AST) and alanine-(ALT) amino transferase, superoxide dismutase (SOD) and catalase (CAT) activities (p < 0.05) but lowered glucose, cholesterol and triglyceride levels in serum. Supplementation of resveratrol helped in increasing the activities of the oxidative enzymes and in improving the plasma total antioxidant capacity (TAOC) and total protein (TP) significantly (p < 0.05) and protein values. The livers of AFB1 group showed degeneration of hepatocytes, bile duct hyperplasia and microgranuloma formation. In resveratrol supplemented birds, the severity and degree of the

  13. Identification of Aspergillus species in Central Europe able to produce G-type aflatoxins.

    PubMed

    Baranyi, Nikolett; Despot, Daniela Jakšić; Palágyi, Andrea; Kiss, Noémi; Kocsubé, Sándor; Szekeres, András; Kecskeméti, Anita; Bencsik, Ottó; Vágvölgyi, Csaba; Klarić, Maja Šegvić; Varga, János

    2015-09-01

    The occurrence of potential aflatoxin producing fungi was examined in various agricultural products and indoor air in Central European countries including Hungary, Serbia and Croatia. For species identification, both morphological and sequence based methods were applied. Aspergillus flavus was detected in several samples including maize, cheese, nuts, spices and indoor air, and several isolates were able to produce aflatoxins. Besides, three other species of Aspergillus section Flavi, A. nomius, A. pseudonomius and A. parasiticus were also isolated from cheese, maize and indoor air, respectively. This is the first report on the occurrence of A. nomius and A. pseudonomius in Central Europe. All A. nomius, A. pseudonomius and A. parasiticus isolates were able to produce aflatoxins B1, B2, G1 and G2. The A. nomius isolate came from cheese produced very high amounts of aflatoxins (above 1 mg ml⁻¹). All A. nomius, A. pseudonomius and A. parasiticus isolates produced much higher amounts of aflatoxin G1 then aflatoxin B1. Further studies are in progress to examine the occurrence of producers of these highly carcinogenic mycotoxins in agricultural products and indoor air in Central Europe.

  14. Natural co-occurrence of ochratoxin A, ochratoxin B and aflatoxins in Sicilian red wines.

    PubMed

    Di Stefano, Vita; Avellone, Giuseppe; Pitonzo, Rosa; Capocchiano, Valentina Giusi; Mazza, Alessia; Cicero, Nicola; Dugo, Giacomo

    2015-01-01

    The natural occurrence of ochratoxin A, ochratoxin B, aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 (OTA, OTB, AFB1, AFB2, AFG1, AFG2) in red wines was investigated by HPLC/FLD after immunoaffinity column clean-up in 57 market samples produced in Sicily (Italy). The results showed a very low incidence of these mycotoxins in analysed samples, confirming the high degree of quality and safety of Sicilian red wines. The results indicated 71.9% and 64.9% positive samples for OTA and OTB respectively, with an average level of 0.13 μg l(-1), well below the European maximum permitted levels (MLs). The aflatoxin most frequently detected in the samples was AFG1, present in 57.9% of samples, while the other aflatoxins were rarely present. Recovery experiments were carried out on eight mycotoxin-free red wines spiked with OTA, OTB, AFB1, AFB2, AFG1 and AFG2 at two different levels. The limits of detection (LODs) in wines were 0.02 µg l(-1) for OTA, 0.04 µg l(-1) for OTB, 0.03 µg l(-1) for AFG1, AFG2 and AFB2, and 0.05 µg l(-1) for AFB1. A good correlation was found, with good performances in term of precision for the method.

  15. Effect of sodium bentonite on the performance and blood variables of broiler chickens intoxicated with aflatoxins.

    PubMed

    Santurio, J M; Mallmann, C A; Rosa, A P; Appel, G; Heer, A; Dageförde, S; Böttcher, M

    1999-03-01

    1. This study was conducted to evaluate the protective effect of natural sodium bentonite (NaB) in the prevention of toxic effects of aflatoxins. Five hundred and twenty-eight 1-d-old Ross male broiler chickens were housed in pens (22 chickens per pen) for 42 d. There were 3 inclusion rates of NaB (0, 2.5, and 5 g/kg) and 2 of aflatoxins (0 and 3 mg/kg food). Each treatment had 4 replicates of 22 chickens. 2. All chickens treated with aflatoxin and without bentonite were adversely affected. NaB treatment at 5.0 g/kg improved body weights at 42 d of age by 31.3%, increased food intake by 23.8% and improved productive efficiency by 40.1%. Weights of liver, heart, pancreas and crop and biochemical variables were not affected by dietary NaB. However, serum phosphorous concentration was reduced by 30% compared with chickens that received aflatoxin. 3. NaB caused no adverse effects on chickens that did not receive aflatoxin. 4. It is concluded that NaB at pH 7.9 partially neutralises the effects of aflatoxins on broiler chickens when included at 5.0 g/kg in the diet.

  16. Toxicity of aflatoxin B1 towards the vitamin D receptor (VDR).

    PubMed

    Costanzo, Paola; Santini, Antonello; Fattore, Luigi; Novellino, Ettore; Ritieni, Alberto

    2015-02-01

    This research describes an unexpected toxicity of the aflatoxin B1 towards the vitamin D receptors. Rickets is a childhood disease, and calcium deficiency is the aetiological cause in Africa, being primarily associated with nutritional problems; in this research the contribution of aflatoxin B1 exposure during the early months of life is an interesting factor to deepen in order to prevent liver damages or the development of rickets. The results show that the expression of vitamin D receptor in osteosarcoma cell line SAOS-2 is significantly down-modulated by exposure to aflatoxin B1. This seems to suggest that Aflatoxin B1, toxic towards the vitamin D receptor, interferes with the actions of the vitamin D on calcium binding gene expression in the kidney and intestine. Experimental data indicate a 58% and 86% decrease if the cells are exposed to 5 ng/mL and 50 ng/mL of aflatoxin B1, respectively. These results seem to indicate that natural occurrence of the aflatoxin B1 and allelic variant of vitamin D receptor on (F allele) increase the risk of developing rickets of African children.

  17. Key roles of vitamins A, C, and E in aflatoxin B1-induced oxidative stress.

    PubMed

    Alpsoy, Lokman; Yalvac, Mehmet Emir

    2011-01-01

    Aflatoxins (Aspergillus flavus toxins) are one of the natural toxic molecules which are produced by a group of fungi called Aspergillus. Foods and drinks contaminated with aflatoxins cause global health and environmental problems. Today in many developing countries, these toxins are leading cause of some liver cancers and serious gastrointestinal problems. Aflatoxins, which are well known to be mutagenic, carcinogenic, hepatotoxic, and immunosuppressive, exert inhibitory effects on biological processes including DNA synthesis, DNA-dependent RNA synthesis, DNA repair, and protein synthesis. Aflatoxins B(1) (AFB(1)) is the most widespread oxidative agent of the aflatoxins. Numerous diverse compounds and extracts have been reported to reduce the aflatoxins induced oxidative stress in the body. Most of these inhibitors including phenylpropanoids, terpenoids, alkaloids, and vitamins are originally derived from plants. Among these, being essential biomolecules, vitamins are used as coenzymes in very significant biological reactions. They also function as nonenzymatic antioxidative agents protecting the cells from oxidative stress-induced toxicity and transformation. This chapter reviews the mechanism of AFB(1)-induced oxidative stress and focuses on the protective effects of vitamins A, C, and E on reducing this stress.

  18. Aflatoxins in Turkish dried figs intended for export to the European Union.

    PubMed

    Senyuva, H Z; Gilbert, J; Ulken, U

    2007-04-01

    Dried figs for export from Turkey from crop years 2003 through 2006 were tested for aflatoxin B1 and total aflatoxins. For export to the European Union, consignments of 0.5 to 10 tonnes of dried figs were sampled according to European Commission regulations, and high-pressure liquid chromatography (HPLC) was used to determine concentrations of aflatoxins Bl, B2, G1, and G2. For each consignment of dried figs, a 30-kg sample (comprising 100 subsamples) was divided into three 10-kg subsamples, which were separately blended and analyzed with HPLC. This monitoring effort was conducted for figs from 2003, 2004, 2005, and up to June 2006, for a total of 10,396 30-kg samples (28,489 analyses). The incidence of contamination with aflatoxin B1 at higher than 2 ng/g was on average 0.6, 2.0, 4.0, and 2.4% for 2003, 2004, 2005, and up to June 2006, respectively, whereas contamination with total aflatoxins at higher than 4 ng/g was 2.6, 3.0, 5.1, and 2.7%. There was significant variability in contamination between replicate 1-kg samples, indicating small numbers of individual contaminated figs were probably responsible. There were also substantial differences in the relative proportions of aflatoxins B1, B2, G1, and G2 among samples, suggesting different contributing fungal sources.

  19. Static Hot Air and Infrared Rays Roasting are Efficient Methods for Aflatoxin Decontamination on Hazelnuts

    PubMed Central

    Siciliano, Ilenia; Dal Bello, Barbara; Zeppa, Giuseppe; Spadaro, Davide; Gullino, Maria Lodovica

    2017-01-01

    Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods—traditional static hot air roasting and infra-red rays roasting—were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts. PMID:28230792

  20. Application of superabsorbent polymers (SAP) as desiccants to dry maize and reduce aflatoxin contamination.

    PubMed

    Mbuge, Duncan O; Negrini, Renata; Nyakundi, Livine O; Kuate, Serge P; Bandyopadhyay, Ranajit; Muiru, William M; Torto, Baldwyn; Mezzenga, Raffaele

    2016-08-01

    The ability of superabsorbent polymers (SAP) in drying maize and controlling aflatoxin contamination was studied under different temperatures, drying times and SAP-to-maize ratios. Temperature and drying time showed significant influence on the aflatoxin formation. SAP-to-maize ratios between 1:1 and 1:5 showed little or no aflatoxin contamination after drying to the optimal moisture content (MC) of 13 %, while for ratios 1:10 and 1:20, aflatoxin contamination was not well controlled due to the overall higher MC and drying time, which made these ratios unsuitable for the drying process. Results clearly show that temperature, frequency of SAP change, drying time and SAP-to-maize ratio influenced the drying rate and aflatoxin contamination. Furthermore, it was shown that SAP had good potential for grain drying and can be used iteratively, which can make this system an optimal solution to reduce aflatoxin contamination in maize, particular for developing countries and resource-lacking areas.

  1. Antifungal Activity and Aflatoxin Degradation of Bifidobacterium Bifidum and Lactobacillus Fermentum Against Toxigenic Aspergillus Parasiticus

    PubMed Central

    Ghazvini, Roshanak Daie; Kouhsari, Ebrahim; Zibafar, Ensieh; Hashemi, Seyed Jamal; Amini, Abolfazl; Niknejad, Farhad

    2016-01-01

    Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B1, B2, G1 and G2 fractions by more than 99%. Moreover, LAB metabolites reduced the level of standard AFB1, B2, G1 and G2 from 88.8% to 99.8% (p≤0.05). Based on these findings, B. bifidum and L. fermentum are recommended as suitable biocontrol agents against the growth and aflatoxin production by aflatoxigenic Aspergillus species. PMID:28077976

  2. Automatic detection of aflatoxin contaminated corn kernels using dual-band imagery

    NASA Astrophysics Data System (ADS)

    Ononye, Ambrose E.; Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Brown, Robert L.; Cleveland, Thomas E.

    2009-05-01

    Aflatoxin is a mycotoxin predominantly produced by Aspergillus flavus and Aspergillus parasitiucus fungi that grow naturally in corn, peanuts and in a wide variety of other grain products. Corn, like other grains is used as food for human and feed for animal consumption. It is known that aflatoxin is carcinogenic; therefore, ingestion of corn infected with the toxin can lead to very serious health problems such as liver damage if the level of the contamination is high. The US Food and Drug Administration (FDA) has strict guidelines for permissible levels in the grain products for both humans and animals. The conventional approach used to determine these contamination levels is one of the destructive and invasive methods that require corn kernels to be ground and then chemically analyzed. Unfortunately, each of the analytical methods can take several hours depending on the quantity, to yield a result. The development of high spectral and spatial resolution imaging sensors has created an opportunity for hyperspectral image analysis to be employed for aflatoxin detection. However, this brings about a high dimensionality problem as a setback. In this paper, we propose a technique that automatically detects aflatoxin contaminated corn kernels by using dual-band imagery. The method exploits the fluorescence emission spectra from corn kernels captured under 365 nm ultra-violet light excitation. Our approach could lead to a non-destructive and non-invasive way of quantifying the levels of aflatoxin contamination. The preliminary results shown here, demonstrate the potential of our technique for aflatoxin detection.

  3. Impact of aflatoxin B1 on the pharmacokinetic disposition of enrofloxacin in broiler chickens.

    PubMed

    Kalpana, Starling; Srinivasa Rao, G; Malik, Jitendra K

    2015-09-01

    The potential impact of subchronic exposure of aflatoxin B1 was investigated on the pharmacokinetic disposition of enrofloxacin in broiler chickens. Broiler chickens given either normal or aflatoxin B1 (750μg/kg diet) supplemented diet for 6 weeks received a single oral dose of enrofloxacin (10mg/kg body wt). Blood samples were drawn from the brachial vein at predetermined time intervals after drug administration. Enrofloxacin plasma concentrations analyzed by RP-HPLC were significantly lower in aflatoxin B1-exposed broiler chickens at 0.167, 0.5 and 1.0h after drug administration. In aflatoxin B1-exposed broiler chickens, the absorption rate constant (ka) of enrofloxacin (0.20±0.05h(-1)) was significantly decreased as compared to the unexposed birds (0.98±0.31h(-1)). The values of [Formula: see text] , tmax and AUC0-∞ of enrofloxacin were nonsignificantly increased by 17%, 26% and 17% in aflatoxin-exposed broiler chickens, respectively. Subchronic aflatoxin B1 exposure markedly decreased the initial absorption of enrofloxacin without significantly influencing other pharmacokinetic parameters in broiler chickens.

  4. Static Hot Air and Infrared Rays Roasting are Efficient Methods for Aflatoxin Decontamination on Hazelnuts.

    PubMed

    Siciliano, Ilenia; Dal Bello, Barbara; Zeppa, Giuseppe; Spadaro, Davide; Gullino, Maria Lodovica

    2017-02-21

    Aflatoxins are a group of secondary metabolites produced by members of Aspergillus Section Flavi that are dangerous to humans and animals. Nuts can be potentially contaminated with aflatoxins, often over the legal threshold. Food processes, including roasting, may have different effects on mycotoxins, and high temperatures have proven to be very effective in the reduction of mycotoxins. In this work, two different roasting methods-traditional static hot air roasting and infra-red rays roasting-were applied and compared for the detoxification of hazelnuts from Italy and Turkey. At the temperature of 140 °C for 40 min of exposure, detoxification was effective for both roasting techniques. Residual aflatoxins after infra-red rays treatments were lower compared to static hot air roasting. On Italian hazelnuts, residual aflatoxins were lower than 5%, while for Turkish hazelnuts they were lower than 15% after 40 min of exposure to an infra-red rays roaster. After roasting, the perisperm was detached from the nuts and analyzed for aflatoxin contents. Residual aflatoxins in the perisperm ranged from 80% up to 100%. After roasting, the lipid profile and the nutritional quality of hazelnuts were not affected. Fatty acid methyl esters analyses showed a similar composition for Italian and Turkish hazelnuts.

  5. The metabolism of aflatoxin B1 by hepatocytes isolated from rats following the in vivo administration of some xenobiotics

    SciTech Connect

    Metcalfe, S.A.; Neal, G.E.

    1983-01-01

    Isolated rat hepatocytes, an intact cellular system capable of performing phase I and phase II metabolism, have been used to investigate metabolism of aflatoxin B1. These cells were found to metabolise (/sup 14/C)aflatoxin B1 to aflatoxins M1 and Q1, and to radiolabelled polar material, presumably conjugates, as analysed by h.p.l.c., t.l.c. and radioactive determination. In vivo administration of the mixed function oxidase inducers, phenobarbitone and 3-methylcholanthrene, resulted in enhanced hepatocyte phase I (microsomal) metabolism of aflatoxin B1. In contrast to metabolism of AFB1 by in vitro subcellular systems increased production of polar material (conjugated metabolites) derived from (/sup 14/C)aflatoxin B1 was also detected in hepatocytes isolated from these pretreated animals. Formation of aflatoxin Q1 by isolated hepatocytes appeared to be mediated by cytochrome P450-linked enzymes whereas cytochrome P448-linked enzymes were apparently involved in aflatoxin M1 production. Chronic feeding of aflatoxin B1 to rats enhanced hepatocyte production of conjugated material only and did not elevate cellular cytochrome P450 levels, thus suggesting that aflatoxin B1 is not an inducer of its own primary metabolism.

  6. Ameliorative effects of black tea extract on aflatoxin-induced lipid peroxidation in the liver of mice.

    PubMed

    Choudhary, Anamika; Verma, R J

    2005-01-01

    We have evaluated the ameliorative effect of black tea extract on aflatoxin-induced lipid peroxidation in the liver of mice. Adult male albino mice were orally administered with 25 and 50 microg of aflatoxin in 0.2 ml olive oil/animal/day for 30 days. Results revealed dose-dependent and significantly (p<0.05) higher lipid peroxidation in the liver of aflatoxin-treated mice than that of vehicle control. As compared with vehicle control, the levels of non-enzymatic antioxidants such as glutathione and ascorbic acid, as well as the enzymatic antioxidants such as superoxide dismutase, glutathione peroxidase and catalase were significantly (p<0.05) lowered in the liver of aflatoxin-treated mice. Oral administration of two percent aqueous black tea extract along with aflatoxin for 30 days (groups 6 and 7) caused significant (p<0.05) amelioration in aflatoxin-induced lipid peroxidation by increasing significantly (p<0.05) the activities of enzymatic (superoxide dismutase, glutathione peroxidase, catalase) and contents of non-enzymatic (glutathione and ascorbic acid) antioxidants in the liver of mice as compared with those given aflatoxin alone (groups 4 and 5). Thus, oral administration of black tea along with aflatoxin significantly (p<0.05) ameliorates aflatoxin-induced lipid peroxidation in the liver of mice.

  7. A comparative study of the effect of aflatoxin B1 and actinomycin D on HeLa cells

    PubMed Central

    Harley, E. H.; Rees, K. R.; Cohen, A.

    1969-01-01

    1. The cytotoxic effects of aflatoxin B1 on HeLa cells were examined and effects of short exposures of the cells to the toxin were found to be reversible. 2. Aflatoxin B1 inhibited the synthesis of both ribosomal and heterodisperse RNA. It is proposed that the toxin's mechanism of action on ribosomal RNA synthesis is related to its inhibitory effect on the maturation of the 45s-ribosomal-RNA precursor. 3. Protein synthesis is inhibited to a greater extent by aflatoxin B1 than by actinomycin D. In contrast with actinomycin D, aflatoxin B1 was shown to disaggregate polyribosomes directly. ImagesPLATE 1PLATE 2 PMID:4897460

  8. Gibberellin biosynthesis in Gibberlla fujikuroi

    SciTech Connect

    Johnson, S.W.; Coolbaugh, R.C. )

    1989-04-01

    Gibberellins (GAs) are a group of plant growth hormones which were first isolated from the fungus Gibberella fujikuori. We have examined the biosynthesis of GAs in this fungus in liquid cultures using HPLC followed by GC-MS. Furthermore we have used cell-free enzyme extracts with {sup 14}C-labeled intermediates to examine the regulation of specific parts of the biosynthetic pathway. GA{sub 3} is the predominant GA in well aerated cultures. GA{sub 4} and GA{sub 7}, intermediates in GA{sub 3} biosynthesis, accumulate in cultures with low levels of dissolved oxygen, but are not detectable in more aerated cultures. Light stimulates GA production in G. fujikuroi cultures grown from young stock. Cell-free enzyme studies indicate that light has no effect on incorporation of mevalonic acid into kaurene, but does significantly stimulate the oxidation of kaurenoic acid.

  9. Biosynthesis of Bacterial Cell Walls.

    DTIC Science & Technology

    amino acid accumulation level in Lactobacillus plantarum and Streptococcus faecalis despite a normal initial transport rate. In the course of these...biosynthesis of a dipeptide, D-alanylcysteine; A demonstration that a pantothenic acid deficiency renders L. plantarum unusually sensitive to lysozyme digestion...A quantitative description of the lipid constituents of S. faecalis and L. plantarum ; An investigation of the biochemical basis of a marked lytic

  10. Stability of Aflatoxin B1 and Ochratoxin A in Brewing

    PubMed Central

    Chu, F. S.; Chang, C. C.; Ashoor, Samy H.; Prentice, N.

    1975-01-01

    The stability of aflatoxin B1 and ochratoxin A in brewing was investigated by adding the purified toxins to the raw materials at 1 and 10 μg/g levels during mashing in a conventional micro-brewing process. The results indicate that both toxins are stable to heat and are insensitive to cooker mash treatment. Both mycotoxins were partially removed in the mashing and brewing processes. About 14 to 18% and 27 to 28% of the added toxins were found in the final beers brewed from starting materials containing 1 and 10 μg, respectively, of either toxin per g. The possible route of transmission of mycotoxins into beer is discussed. PMID:1115503

  11. Aflatoxin M₁ in breast milk of nursing Sudanese mothers.

    PubMed

    Elzupir, Amin O; Abas, Abdel Rouf A; Fadul, M Hemmat; Modwi, Abueliz K; Ali, Nima M I; Jadian, Afaf F F; Ahmed, Nuha Abd A; Adam, Smah Y A; Ahmed, Nousiba A M; Khairy, Arwa A A; Khalil, Eltahir A G

    2012-05-01

    The presence of aflatoxin M1 (AFM1) in the breast milk of nursing Sudanese mothers was investigated using AOAC official method 980.21 as the extraction method and HPLC with fluorescence detector for separation and detection. Following informed consent, 94 breast milk samples of mothers were collected, and 51 samples were found to be positive for AFM1, with an average concentration of 0.401 ± 0.525 ng g(-1) and a maximum level of 2.561 ng g(-1). The volunteers completed a questionnaire concerning their dietary preferences. The data collected suggest that peanut butter, vegetable oils and rice are the main sources responsible for the AFM1 burden in breast milk. The toxin levels are alarmingly high, and indicate that Sudanese infants are exposed to high levels of AFM1. A wide range of harmful effects, and consequently health problems, can be expected due AFM1 toxicity.

  12. Survey of fungal counts and natural occurrence of aflatoxins in Malaysian starch-based foods.

    PubMed

    Abdullah, N; Nawawi, A; Othman, I

    1998-01-01

    In a survey of starch-based foods sampled from retail outlets in Malaysia, fungal colonies were mostly detected in wheat flour (100%), followed by rice flour (74%), glutinous rice grains (72%), ordinary rice grains (60%), glutinous rice flour (48%) and corn flour (26%). All positive samples of ordinary rice and glutinous rice grains had total fungal counts below 10(3) cfu/g sample, while among the positive rice flour, glutinous rice flour and corn flour samples, the highest total fungal count was more than 10(3) but less than 10(4) cfu/g sample respectively. However, in wheat flour samples total fungal count ranged from 10(2) cfu/g sample to slightly more than 10(4) cfu/g sample. Aflatoxigenic colonies were mostly detected in wheat flour (20%), followed by ordinary rice grains (4%), glutinous rice grains (4%) and glutinous rice flour (2%). No aflatoxigenic colonies were isolated from rice flour and corn flour samples. Screening of aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2 using reversed-phase HPLC were carried out on 84 samples of ordinary rice grains and 83 samples of wheat flour. Two point four percent (2.4%) of ordinary rice grains were positive for aflatoxin G1 and 3.6% were positive for aflatoxin G2. All the positive samples were collected from private homes at concentrations ranging from 3.69-77.50 micrograms/kg. One point two percent (1.2%) of wheat flour samples were positive for aflatoxin B1 at a concentration of 25.62 micrograms/kg, 4.8% were positive for aflatoxin B2 at concentrations ranging from 11.25-252.50 micrograms/kg, 3.6% were positive for aflatoxin G1 at concentrations ranging from 25.00-289.38 micrograms/kg and 13.25% were positive for aflatoxin G2 at concentrations ranging from 16.25-436.25 micrograms/kg. Similarly, positive wheat flour samples were mostly collected from private homes.

  13. Thyroid hormone biosynthesis and release.

    PubMed

    Carvalho, Denise P; Dupuy, Corinne

    2017-01-31

    Thyroid hormones (TH) 3,5,3',5'- tetraiodothyronine or thyroxine (T4) and 3,5,3'- triiodothyronine (T3) contain iodine atoms as part of their structure, and their synthesis occur in the unique structures called thyroid follicles. Iodide reaches thyroid cells through the bloodstream that supplies the basolateral plasma membrane of thyrocytes, where it is avidly taken up through the sodium/iodide symporter (NIS). Thyrocytes are also specialized in the secretion of the high molecular weight protein thyroglobulin (TG) in the follicular lumen. The iodination of the tyrosyl residues of TG preceeds TH biosynthesis, which depends on the interaction of iodide, TG, hydrogen peroxide (H2O2) and thyroid peroxidase (TPO) at the apical plasma membrane of thyrocytes. Thyroid hormone biosynthesis is under the tonic control of thyrotropin (TSH), while the iodide recycling ability is very important for normal thyroid function. We discuss herein the biochemical aspects of TH biosynthesis and release, highlighting the novel molecules involved in the process.

  14. Aflatoxin B1 Degradation by a Pseudomonas Strain

    PubMed Central

    Sangare, Lancine; Zhao, Yueju; Folly, Yawa Minnie Elodie; Chang, Jinghua; Li, Jinhan; Selvaraj, Jonathan Nimal; Xing, Fuguo; Zhou, Lu; Wang, Yan; Liu, Yang

    2014-01-01

    Aflatoxin B1 (AFB1), one of the most potent naturally occurring mutagens and carcinogens, causes significant threats to the food industry and animal production. In this study, 25 bacteria isolates were collected from grain kernels and soils displaying AFB1 reduction activity. Based on its degradation effectiveness, isolate N17-1 was selected for further characterization and identified as Pseudomonas aeruginosa. P. aeruginosa N17-1 could degrade AFB1, AFB2 and AFM1 by 82.8%, 46.8% and 31.9% after incubation in Nutrient Broth (NB) medium at 37 °C for 72 h, respectively. The culture supernatant of isolate N17-1 degraded AFB1 effectively, whereas the viable cells and intra cell extracts were far less effective. Factors influencing AFB1 degradation by the culture supernatant were investigated. Maximum degradation was observed at 55 °C. Ions Mn2+ and Cu2+ were activators for AFB1 degradation, however, ions Mg2+, Li+, Zn2+, Se2+, Fe3+ were strong inhibitors. Treatments with proteinase K and proteinase K plus SDS significantly reduced the degradation activity of the culture supernatant. No degradation products were observed based on preliminary LC-QTOF/MS analysis, indicating AFB1 was metabolized to degradation products with chemical properties different from that of AFB1. The results indicated that the degradation of AFB1 by P. aeruginosa N17-1 was enzymatic and could have a great potential in industrial applications. This is the first report indicating that the isolate of P. aeruginosa possesses the ability to degrade aflatoxin. PMID:25341538

  15. FSH stimulates lipid biosynthesis in chicken adipose tissue by upregulating the expression of its receptor FSHR.

    PubMed

    Cui, Huanxian; Zhao, Guiping; Liu, Ranran; Zheng, Maiqing; Chen, Jilan; Wen, Jie

    2012-05-01

    Transcripts and protein for follicle-stimulating hormone receptor (FSHR) were demonstrated in abdominal adipose tissue of female chickens. There was no expression of the Fsh gene, but FSH and FSHR colocalized, suggesting that FSH was receptor bound. Partial correlations indicted that changes in abdominal fat (AF) content were most directly correlated with Fshr mRNA expression, and the latter was directly correlated with tissue FSH content. These relationships were consistent with FSH inducing Fshr mRNA expression and with the finding that FSH influenced the accumulation of AF in chickens, a novel role for the hormone. Chicken preadipocytes responded linearly to doubling concentrations of FSH in Fshr mRNA expression and quantities of FSHR and lipid, without discernable effect on proliferation. Cells exposed to FSH more rapidly acquired adipocyte morphology. Treatment of young chickens with chicken FSH (4 mIU/day, subcutaneous, days 7-13) did not significantly decrease live weight but increased AF weight by 54.61%, AF as a percentage of live weight by 55.45%, and FSHR transcripts in AF by 222.15% (2 h after injection). In cells stimulated by FSH, genes related to lipid metabolism, including Rdh10, Dci, RarB, Lpl, Acsl3, and Dgat2, were expressed differentially, compared with no FSH. Several pathways of retinal and fatty acid metabolism, and peroxisome proliferator-activated receptor (PPAR) signaling changed. In conclusion, FSH stimulates lipid biosynthesis by upregulating Fshr mRNA expression in abdominal adipose tissue of chickens. Several genes involved in fatty acid and retinal metabolism and the PPAR signaling pathway mediate this novel function of FSH.

  16. The transfer of aflatoxin M1 in milk of ewes fed diet naturally contaminated by aflatoxins and effect of inclusion of dried yeast culture in the diet.

    PubMed

    Battacone, G; Nudda, A; Palomba, M; Mazzette, A; Pulina, G

    2009-10-01

    An experiment was carried out to investigate 1) the transfer of aflatoxin M1 (AFM1) into the milk of dairy ewes fed diets naturally contaminated with aflatoxin B1 (AFB1); 2) the effect of the addition of dried yeast culture in the diet on this transfer; and 3) the alteration of enzymatic activities in the liver of ewes fed diets contaminated with AFB1. Twenty-four Sarda dairy ewes were divided in 4 groups and fed a concentrate mix containing 4 amounts of wheat meal naturally contaminated with aflatoxins. The diet of the control group had no wheat meal, whereas that of treated groups had low, medium, or high amounts of contaminated wheat, which corresponded to 1.13, 2.30, and 5.03 microg of AFB1/kg of feed, respectively. The experiment lasted 14 d. On d 8 to 14 from the beginning of the trial, 12 g/d of a commercial dried yeast product (DYP) of Kluyveromyces lactis was added to the diet of each ewe. The AFM1 concentration in individual milk samples and the blood serum metabolites were measured periodically. The presence of AFM1 was first detected in milk on d 1 of administration, and then its concentration increased and approached a steady-state condition on d 3 simultaneously in all treated groups. The AFM1 in milk at the steady-state condition, which was linearly related to the AFB1 intake, was 39.72, 50.38, and 79.29 ng/L in the low-aflatoxin, medium-aflatoxin, and high-aflatoxin groups, respectively. The AFM1 concentration in milk of the high-aflatoxin group was approximately 1.5-fold greater than the European Commission maximum tolerance level (50 ng/kg). The addition of DYP to the diet did not affect the AFM1 concentration in milk. After the withdrawal of the contaminated concentrate mix, the AFM1 mean concentrations decreased quickly and were no longer detected after 3 d in all treated groups. Daily milk yield and composition did not differ because of aflatoxin treatment. Blood serum parameters (creatinine, glutamic oxalacetic transaminase, glutamic pyruvic

  17. Development of an Enzyme-Linked Immunosorbent Assay Method Specific for the Detection of G-Group Aflatoxins.

    PubMed

    Li, Peiwu; Zhou, Qian; Wang, Ting; Zhou, Haiyan; Zhang, Wen; Ding, Xiaoxia; Zhang, Zhaowei; Chang, Perng-Kuang; Zhang, Qi

    2015-12-28

    To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G₁ and G₂. Of the final three positive and stable hybridomas obtained, clone 2G6 produced a monoclonal antibody that had equal sensitivity to aflatoxins G₁ and G₂, and did not cross-react with aflatoxins B₁, B₂, or M₁. Its IC50 values for aflatoxins G₁ and G₂ were 17.18 ng·mL(-1) and 19.75 ng·mL(-1), respectively. Using this new monoclonal antibody, we developed a competitive indirect enzyme-linked immunosorbent assay (CI-ELISA); the method had a limit of detection of 0.06 ng·mL(-1). To validate this CI-ELISA, we spiked uncontaminated peanut samples with various amounts of aflatoxins G₁ and G₂ and compared recovery rates with those determined by a standard HPLC method. The recovery rates of the CI-ELISA ranging from 94% to 103% were comparable to those of the HPLC (92% to 102%). We also used both methods to determine the amounts of G-group aflatoxins in five peanut samples contaminated by aflatoxin B₁-positive, and their relative standard deviations ranged from 8.4% to 17.7% (under 20%), which demonstrates a good correlation between the two methods. We further used this CI-ELISA to assess the ability of 126 fungal strains isolated from peanuts or field soils to produce G-group aflatoxins. Among these, seven stains producing different amounts of G-group aflatoxins were identified. Our results showed that the monoclonal antibody 2 G6-based CI-ELISA was suitable for the detection of G-group aflatoxins present in peanuts and also those produced by fungi.

  18. Determination of the aflatoxin M1 (AFM1) from milk by direct analysis in real time - mass spectrometry (DART-MS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain fungi that grow on crops can produce aflatoxins, which are highly carcinogenic. One of these, aflatoxin B1 can be metabolized by mammals to aflatoxin M1, a form that retains potent carcinogenicity and which can be excreted into milk. Direct analysis in real time (DART) ionization coupled to ...

  19. Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus

    PubMed Central

    Esper, Renata H.; Gonçalez, Edlayne; Marques, Marcia O. M.; Felicio, Roberto C.; Felicio, Joana D.

    2014-01-01

    Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10 μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3 × 105 spores/mL in 60 g of grains (corn and soybeans) after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans. PMID:24926289

  20. Potential of essential oils for protection of grains contaminated by aflatoxin produced by Aspergillus flavus.

    PubMed

    Esper, Renata H; Gonçalez, Edlayne; Marques, Marcia O M; Felicio, Roberto C; Felicio, Joana D

    2014-01-01

    Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oils of Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) on the mycelial growth and aflatoxin B1 production by Aspergillus flavus have been studied previously in culture medium. The aim of this study was to evaluate aflatoxin B1 production by Aspergillus flavus in real food systems (corn and soybean) treated with Ageratum conyzoides (mentrasto) and Origanum vulgare (oregano) essential oils. Samples with 60 g of the grains were treated with different volumes of essential oils, 200, 100, 50, and 10 μL for oregano and 50, 30, 15, and 10 μL for mentrasto. Fungal growth was evaluated by disk diffusion method. Aflatoxin B1 production was evaluated inoculating suspensions of A. flavus containing 1.3 × 10(5) spores/mL in 60 g of grains (corn and soybeans) after adjusting the water activity at 0.94. Aflatoxin was quantified by photodensitometry. Fungal growth and aflatoxin production were inhibited by essential oils, but the mentrasto oil was more effective in soybeans than that of oregano. On the other hand, in corn samples, the oregano essential oil was more effective than that of mentrasto. Chemical compositions of the essential oils were also investigated. The GC/MS oils analysis showed that the main component of mentrasto essential oil is precocene I and of the main component of oregano essential oil is 4-terpineol. The results indicate that both essential oils can become an alternative for the control of aflatoxins in corn and soybeans.

  1. Does aflatoxin exposure in the United Kingdom constitute a cancer risk?

    PubMed Central

    Harrison, J C; Carvajal, M; Garner, R C

    1993-01-01

    Although the aflatoxins were discovered more than 30 years ago, there is still considerable controversy surrounding their human health effects. Most countries have introduced legislation to control the level of aflatoxins in food, but it is not known if these permitted levels still pose a significant cancer risk. Furthermore, it is unlikely that all the sources of human aflatoxin exposure have been discovered, nor if the liver is the only, or indeed, major target organ for aflatoxin-induced cancer in man. In our laboratory we have used both immunological and HPLC methods to examine human DNA from a variety of tissues and organs to identify and quantify aflatoxin DNA-adducts. We have already detected aflatoxin B1 (AFB1)-DNA adducts in formalin-fixed tissue from an acute poisoning incident in Southeast Asia. Here we have examined human colon and rectum DNA from normal and tumorous tissue obtained from cancer patients and colon, liver, pancreas, breast, and cervix DNA from autopsy specimens. AFB1-DNA adducts were detected in all tissue types examined and ranged from 0-60 adducts/10(6) nucleotides. Where sample size allowed, the adduct levels were confirmed by HPLC analysis. Tumor tissues tended to have higher adduct levels than normal tissue from the same individual, and levels generally increased with patient age. In samples analyzed by HPLC, the adducts present had the chromatographic properties of [8,9-dihydro-8-(N5-formyl)-2',5',6'-triamino-4'-oxo-(N5-pyramidyl) -9- hydroxy-aflatoxin B1, the ring-opened form of the AFB1-guanine adduct.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8319666

  2. Non-aflatoxigenic Aspergillus flavus to prevent aflatoxin contamination in crops: advantages and limitations

    PubMed Central

    Ehrlich, Kenneth C.

    2014-01-01

    Aspergillus flavus is a diverse assemblage of strains that include aflatoxin-producing and non-toxigenic strains with cosmopolitan distribution. The most promising strategy currently being used to reduce preharvest contamination of crops with aflatoxin is to introduce non-aflatoxin (biocontrol) A. flavus into the crop environment. Whether or not introduction of biocontrol strains into agricultural fields is enough to reduce aflatoxin contamination to levels required for acceptance of the contaminated food as fit for consumption is still unknown. There is no question that biocontrol strains are able to reduce the size of the populations of aflatoxin-producing strains but the available data suggests that at most only a four- to five-fold reduction in aflatoxin contamination is achieved. There are many challenges facing this strategy that are both short term and long term. First, the population biology of A. flavus is not well understood due in part to A. flavus’s diversity, its ability to form heterokaryotic reproductive forms, and its unknown ability to survive for prolonged periods after application. Second, biocontrol strains must be selected that are suitable for the environment, the type of crop, and the soil into which they will be introduced. Third, there is a need to guard against inadvertent introduction of A. flavus strains that could impose an additional burden on food safety and food quality, and fourth, with global warming and resultant changes in the soil nutrients and concomitant microbiome populations, the biocontrol strategy must be sufficiently flexible to adapt to such changes. Understanding genetic variation within strains of A. flavus is important for developing a robust biocontrol strategy and it is unlikely that a “one size fits all” strategy will work for preharvest aflatoxin reduction. PMID:24575088

  3. Common African cooking processes do not affect the aflatoxin binding efficacy of refined calcium montmorillonite clay

    PubMed Central

    Elmore, Sarah E.; Mitchell, Nicole; Mays, Travis; Brown, Kristal; Marroquin-Cardona, Alicia; Romoser, Amelia; Phillips, Timothy D.

    2013-01-01

    Aflatoxins are common contaminants of staple crops, such as corn and groundnuts, and a significant cause of concern for food safety and public health in developing countries. Aflatoxin B1 (AFB1) has been implicated in the etiology of acute and chronic disease in humans and animals, including growth stunting, liver cancer and death. Cost effective and culturally acceptable intervention strategies for the reduction of dietary AFB1 exposure are of critical need in populations at high risk for aflatoxicosis. Fermented gruels consisting of cornmeal are a common source for such exposure and are consumed by both children and adults in many countries with a history of frequent, high-level aflatoxin exposure. One proposed method to reduce aflatoxins in the diet is to include a selective enterosorbent, Uniform Particle Size NovaSil (UPSN), as a food additive in contaminated foods. For UPSN to be effective in this capacity, it must be stable in complex, acidic mixtures that are often exposed to heat during the process of fermented gruel preparation. Therefore, the objective of the present study was to test the ability of UPSN to sorb aflatoxin while common cooking conditions were applied. The influence of fermentation, heat treatment, acidity, and processing time were investigated with and without UPSN. Analyses were performed using the field-practical Vicam assay with HPLC verification of trends. Our findings demonstrated that UPSN significantly reduced aflatoxin levels (47-100%) in cornmeal, regardless of processing conditions. Upon comparison of each element tested, time appeared to be the primary factor influencing UPSN efficacy. The greatest decreases in AFB1 were reported in samples allowed to incubate (with or without fermentation) for 72 hrs. This data suggests that addition of UPSN to staple corn ingredients likely to contain aflatoxins would be a sustainable approach to reduce exposure. PMID:24311894

  4. Hepatocellular carcinoma p53 G > T transversions at codon 249: the fingerprint of aflatoxin exposure?

    PubMed

    Lasky, T; Magder, L

    1997-04-01

    The molecular epidemiology of p53 mutations allows the possibility of correlating particular mutations with specific environmental carcinogens and establishing one step in the causal pathway between exposure to carcinogens and the development of cancer. A striking example is the G > T transversion at the third base pair of codon 249 observed in liver cancer patients possibly exposed to high levels of aflatoxins in their agricultural products. In this paper, we describe a systematic review of the literature and access the quality of the available data. We found methodologic limitations in the studies. In particular, the key independent variable, aflatoxin exposure, was not assessed in these studies, with the exception of one study that measured a marker of exposure. Instead, nationality, geographic residence, or geographic site of hospital were used as surrogate markers for exposure. Patients from areas with high aflatoxin levels were more likely to have p53 mutations than were patients from areas with low aflatoxin levels. In the group with p53 mutations, patients from areas with high aflatoxin levels had higher proportions of mutations with codon 249 G > T transversions. The differences in proportions with p53 mutations were significant, as were the differences in proportions of codon 249 G > T transversions among patients with p53 mutations. Aflatoxin may increase the proportion of p53 mutations by causing a single mutation, the codon 249 G > T transversion, thus explaining some of the excess liver cancer associated with aflatoxin exposure. However, it is premature to conclude that p53 mutations are established markers for environmental carcinogens.

  5. Surveillance of Aflatoxin and Microbiota Related to Brewer's Grain Destined for Swine Feed in Argentina

    PubMed Central

    Gerbaldo, Gisela A.; Pereyra, Carina M.; Cavaglieri, Lilia R.; Ruiz, Francisco; Pascual, Liliana; Dalcero, Ana M.; Barberis, Isabel L.

    2011-01-01

    Córdoba province in the center of Argentina is an important area of swine production. The use of industry by-product (brewer's grain) as feedstuff for swine is a regular practice and increases animal performance on these animals production. The occurrence of aflatoxin contamination is global, causing severe problems especially in developing countries. No reports on aflatoxin B1 production, micoflora, and potential aflatoxin B1 producing microorganism from brewer's grain are available. The aims of this study were (1) to isolate the microbiota species from brewer's grain, (2) to determine aflatoxin B1 natural contamination levels, and (3) to determine the ability of Aspergillus section Flavi isolates to produce aflatoxins in vitro. Physical properties, total fungal counts, lactic acid bacteria, and fungal genera distribution were determined on this substrate. In 65% of the samples, fungal counts were higher than recommended by GMP, and lactic bacterium counts ranged from 1.9 × 105 to 4.4 × 109 CFU g−1. Aspergillus spp. prevailed over other fungal genera. Aspergillus flavus was the prevalent species followed by A. fumigatus. Aflatoxin B1 levels in the samples were higher than the recommended limits (20 ng g−1) for complementary feedstuffs. Several Aspergillus section Flavi strains were able to produce aflatoxin B1  in vitro. Inadequate storage conditions promote the proliferation of mycotoxin-producing fungal species. Regular monitoring of feeds is required in order to prevent chronic and acute toxic syndromes related to this kind of contamination. PMID:21547231

  6. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  7. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  8. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  9. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  10. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  11. Part III: AFS - A Secure Distributed File System

    SciTech Connect

    Wachsmann, A.; /SLAC

    2005-06-29

    AFS is a secure distributed global file system providing location independence, scalability and transparent migration capabilities for data. AFS works across a multitude of Unix and non-Unix operating systems and is used at many large sites in production for many years. AFS still provides unique features that are not available with other distributed file systems even though AFS is almost 20 years old. This age might make it less appealing to some but with IBM making AFS available as open-source in 2000, new interest in use and development was sparked. When talking about AFS, people often mention other file systems as potential alternatives. Coda (http://www.coda.cs.cmu.edu/) with its disconnected mode will always be a research project and never have production quality. Intermezzo (http://www.inter-mezzo.org/) is now in the Linux kernel but not available for any other operating systems. NFSv4 (http://www.nfsv4.org/) which picked up many ideas from AFS and Coda is not mature enough yet to be used in serious production mode. This article presents the rich features of AFS and invites readers to play with it.

  12. DDX6 transfers P-TEFb kinase to the AF4/AF4N (AFF1) super elongation complex

    PubMed Central

    Mück, Fabian; Bracharz, Silvia; Marschalek, Rolf

    2016-01-01

    AF4/AFF1 and AF5/AFF4 are both backbones for the assembly of “super elongation complexes” (SECs) that exert 2 distinct functions after the recruitment of P-TEFb from the 7SK snRNP: (1) initiation and elongation of RNA polymerase II gene transcription, and (2) modification of transcribed gene regions by distinct histone methylation patterns. In this study we aimed to investigate one of the initial steps, namely how P-TEFb is transferred from 7SK snRNPs to the SECs. In particular, we were interested in the role of DDX6 that we have recently identified as part of the AF4 complex. DDX6 is an evolutionarily conserved member of the DEAD-box RNA helicase family that is known to control miRNA and mRNA biology (translation, storage and degradation). Overexpressed DDX6 is associated with different cancer types and with c-Myc protein overexpression. We could demonstrate that DDX6 binds to 7SK snRNA and causes the release and transfer of P-TEFb to the AF4/AF4N SEC. DDX6 also binds stably to AF4 and AF4N as demonstrated by GST pull-down and co-immunoprecipitation experiments. As a consequence, overexpression of either AF4/AF4N or DDX6 resulted in a strong increase of mRNA production (5-6 fold), while their simultaneous expression increased the cellular mRNA production by 11-fold. Conversely, the corresponding knockdown of DDX6 decreased mRNA production by 70%. In conclusion, AF4/AF4N and DDX6 represent key molecules for the elongation process of gene transcription and a model will be proposed for the hand-over process of P-TEFb to SECs. PMID:27679741

  13. Compliance Testing of the Clear AFS Power Plant, Coal-Fired Boiler 1 Clear AFS, Alaska

    DTIC Science & Technology

    1989-10-01

    Background On 3 February 1987 Clear AFS requested a permit modification to allow limited burning of waste oil for their power plant shown in Figure 1...The Alaska DEC rescindel Permit to Operate No. 8331-AA003 and issued Permit No. 8731-AA004 (Appendix B) allowing the burning of waste oil. As a...below. 1. Visible Emissions (18 AAC 50.050(a)) Visible emissions, excluding condensed water vapor from an industrial process or fuel burning

  14. Occurrence of aflatoxins M(1) and M(2) in milk commercialized in Ribeirão Preto-SP, Brazil.

    PubMed

    Garrido, N S; Iha, M H; Santos Ortolani, M R; Duarte Fávaro, R M

    2003-01-01

    Aflatoxins are toxic metabolites found in foods and feeds. When ruminants eat foodstuffs containing aflatoxins B(1) and B(2), these toxins are metabolized and excreted as aflatoxin M(1) and M(2) in milk. The aim was to determine the incidence of these aflatoxins in commercial milk collected from supermarkets in Ribeirão Preto-SP, Brazil, and consisting of 60 ultrahigh temperature (UHT) milk samples and 79 pasteurized milk samples. The milk samples were analysed according to method 986.16 of AOAC International. None of the milk samples analysed were contaminated with aflatoxin M(2), and aflatoxin M(1) was detected in 29 (20.9%) of samples in the range 50-240 ng l(-1). The results show that despite a high occurrence of aflatoxin M(1) in commercial pasteurized and UHT milk sold in Ribeirão Preto in 1999 and 2000, the contamination level of these toxins could not be considered a serious public health problem according to MERCOSUR Technical Regulations. However, levels in 20.9% of the milk samples exceeded the concentration of 50 ng l(-1) permitted by the European Union. Although it is not necessary to continue monitoring the incidence and levels of aflatoxins M(1) and M(2) in milk samples, surveillance could be appropriate.

  15. Development of an enzyme-linked immunosorbent assay method specific for the detection of G-group aflatoxins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To detect and monitor G-group aflatoxins in agricultural products, we generated class-specific monoclonal antibodies that specifically recognized aflatoxins G1 and G2. Of the final three positive and stable hybridomas obtained, hybridoma 2G6 produced a monoclonal antibody that did not cross-react wi...

  16. Comparison of the side-needle and knife techniques for inducing Aspergillus flavus infection and aflatoxin accumulation in corn hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aflatoxin in corn grain is a problem in many areas of the world. Any combination of environmentally stressful or agronomically unfavorable conditions can increase the likelihood of Aspergillus flavus infection and production of aflatoxin in the corn grain. In the absence of a consistent natural A....

  17. Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1 †

    PubMed Central

    Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

    2014-01-01

    Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B1 after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B1 degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B1 was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B1 degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B1 degradation by the supernatant were examined. Results indicated that aflatoxin B1 degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment. PMID:25401962

  18. Degradation kinetics of aflatoxin B1 and B2 in filter paper and rough rice by using pulsed light irradiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rough rice is susceptible to contamination by aflatoxins, which are highly toxic, mutagenic and carcinogenic compounds. To develop aflatoxin degradation technology for rice with the use of pulsed light (PL) treatment, the objective of this study was to investigate the degradation characters of aflat...

  19. Evaluation of intraspecific competition (Aspergillus flavus Link) and aflatoxin formation in suspended disc culture and preharvest maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The abilities of non-aflatoxin producing strains of Aspergillus flavus NRRL 32354; 18543; 21882; 21368 as well as domesticated koji strains Aspergillus oryzae (syn. A. flavus var. oryzae) NRRL 451; 1911; 5592; 6271; 30038 to interfere with aflatoxin formation by A. flavus NRRL 3357; 32355 were exami...

  20. Evaluation of maize inbred lines for resistance to pre-harvest aflatoxin and fumonisin contamination in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two important mycotoxins, aflatoxin and fumonisin, are among the most potent naturally occurring carcinogens, contaminating maize (Zea mays L.) and affecting the crop yield and quality. Resistance of maize to pre-harvest mycotoxin contamination, specifically aflatoxin produced by Aspergillus flavus ...