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Astoreca A, Vaamonde G, Dalcero A, Marin S, Ramos A. Abiotic factors and their interactions influence on the co-production of aflatoxin B(1) and cyclopiazonic acid by Aspergillus flavus isolated from corn. Food Microbiol 2013; 38:276-83. [PMID: 24290652 DOI: 10.1016/j.fm.2013.07.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/14/2013] [Accepted: 07/29/2013] [Indexed: 11/18/2022]
Abstract
The objectives of this study were i) to determine the effects of the interactions of water activity, temperature and incubation time on the co-production of AFB1 and CPA by isolates of Aspergillus flavus with different profile of mycotoxin production and ii) to identify the aW and temperature limiting conditions for the production of both mycotoxins. Fungi used in this study were selected because they belonged to different chemotypes: chemotype I (AFB1+/CPA+), III (AFB1+/CPA-) and IV (AFB1-/CPA+), respectively. Two culture media were used; Czapek yeast agar (CYA) and corn extract agar (CEM), at different incubated temperatures (10-40 °C) and aW levels (0.80-0.98). AFB1 and CPA production were analyzed after 7, 14, 21 and 28 days of incubation. Significant differences were observed with respect to mycotoxin production depending on the media evaluated. The AFB1 production occurred more favorably on CYA while the highest CPA concentrations were recorded on CEM. Within the range of aW evaluated in this study, 0.83 was the limiting level for both toxins production. The optimum conditions for AFB1 production occurred at 0.96 aW and 30 °C after 21 days of incubation, regardless of the media and isolate. Although different amounts of toxins were produced in each medium, the limiting and optimum conditions for their production were similar in both. No differences in the response of the three isolates to the abiotic factors discussed were observed despite belonging to different chemotypes. The determination of the thresholds of mycotoxins co-production, especially in the case of data obtained with the corn extract medium can be useful to avoid the conditions conducive to co-occurrence of these mycotoxins in corn.
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Affiliation(s)
- Andrea Astoreca
- Laboratorio de Microbiología de Alimentos, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, UBA, Buenos Aires, Argentina.
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53
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Rosada LJ, Sant'anna JR, Franco CCS, Esquissato GNM, Santos PASR, Yajima JPRS, Ferreira FD, Machinski M, Corrêa B, Castro-Prado MAA. Identification of Aspergillus flavus isolates as potential biocontrol agents of aflatoxin contamination in crops. J Food Prot 2013; 76:1051-5. [PMID: 23726204 DOI: 10.4315/0362-028x.jfp-12-436] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Aspergillus flavus, a haploid organism found worldwide in a variety of crops, including maize, cottonseed, almond, pistachio, and peanut, causes substantial and recurrent worldwide economic liabilities. This filamentous fungus produces aflatoxins (AFLs) B1 and B2, which are among the most carcinogenic compounds from nature, acutely hepatotoxic and immunosuppressive. Recent efforts to reduce AFL contamination in crops have focused on the use of nonaflatoxigenic A. flavus strains as biological control agents. Such agents are applied to soil to competitively exclude native AFL strains from crops and thereby reduce AFL contamination. Because the possibility of genetic recombination in A. flavus could influence the stability of biocontrol strains with the production of novel AFL phenotypes, this article assesses the diversity of vegetative compatibility reactions in isolates of A. flavus to identify heterokaryon self-incompatible (HSI) strains among nonaflatoxigenic isolates, which would be used as biological controls of AFL contamination in crops. Nitrate nonutilizing (nit) mutants were recovered from 25 A. flavus isolates, and based on vegetative complementation between nit mutants and on the microscopic examination of the number of hyphal fusions, five nonaflatoxigenic (6, 7, 9 to 11) and two nontoxigenic (8 and 12) isolates of A. flavus were phenotypically characterized as HSI. Because the number of hyphal fusions is reduced in HSI strains, impairing both heterokaryon formation and the genetic exchanges with aflatoxigenic strains, the HSI isolates characterized here, especially isolates 8 and 12, are potential agents for reducing AFL contamination in crops.
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Affiliation(s)
- L J Rosada
- Departamento de Biotecnologia, Genética e Biologia Celular, Laboratório de Genética de Microrganismos, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, CEP 87020-900, PR, Brasil
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Effect of water activity and temperature on the germination and growth of Aspergillus tamarii isolated from “Maldive fish”. Int J Food Microbiol 2012. [DOI: 10.1016/j.ijfoodmicro.2012.09.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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55
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Olarte RA, Horn BW, Dorner JW, Monacell JT, Singh R, Stone EA, Carbone I. Effect of sexual recombination on population diversity in aflatoxin production by Aspergillus flavus and evidence for cryptic heterokaryosis. Mol Ecol 2011; 21:1453-76. [PMID: 22212063 DOI: 10.1111/j.1365-294x.2011.05398.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aspergillus flavus is the major producer of carcinogenic aflatoxins (AFs) in crops worldwide. Natural populations of A. flavus show tremendous variation in AF production, some of which can be attributed to environmental conditions, differential regulation of the AF biosynthetic pathway and deletions or loss-of-function mutations in the AF gene cluster. Understanding the evolutionary processes that generate genetic diversity in A. flavus may also explain quantitative differences in aflatoxigenicity. Several population studies using multilocus genealogical approaches provide indirect evidence of recombination in the genome and specifically in the AF gene cluster. More recently, A. flavus has been shown to be functionally heterothallic and capable of sexual reproduction in laboratory crosses. In the present study, we characterize the progeny from nine A. flavus crosses using toxin phenotype assays, DNA sequence-based markers and array comparative genome hybridization. We show high AF heritability linked to genetic variation in the AF gene cluster, as well as recombination through the independent assortment of chromosomes and through crossing over within the AF cluster that coincides with inferred recombination blocks and hotspots in natural populations. Moreover, the vertical transmission of cryptic alleles indicates that while an A. flavus deletion strain is predominantly homokaryotic, it may harbour AF cluster genes at a low copy number. Results from experimental matings indicate that sexual recombination is driving genetic and functional hyperdiversity in A. flavus. The results of this study have significant implications for managing AF contamination of crops and for improving biocontrol strategies using nonaflatoxigenic strains of A. flavus.
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Affiliation(s)
- Rodrigo A Olarte
- Department of Plant Pathology, Center for Integrated Fungal Research, North Carolina State University, Raleigh, NC 27695, USA
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56
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King ED, Bobby Bassi AB, Ross DC, Druebbisch B. An industry perspective on the use of "atoxigenic" strains of Aspergillus flavus as biological control agents and the significance of cyclopiazonic acid. TOXIN REV 2011; 30:33-41. [PMID: 22844262 PMCID: PMC3339596 DOI: 10.3109/15569543.2011.588818] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 05/12/2011] [Indexed: 01/13/2023]
Abstract
Several nonaflatoxigenic strains of Aspergillus flavus have been registered in the United States to reduce aflatoxin accumulation in maize and other crops, but there may be unintended negative consequences if these strains produce cyclopiazonic acid (CPA). AF36, a nonaflatoxigenic, CPA-producing strain has been shown to produce CPA in treated maize and peanuts. Alternative strains, including Afla-Guard® brand biocontrol agent and K49, do not produce CPA and can reduce both aflatoxin and CPA in treated crops. Chronic toxicity of CPA has not been studied, and recent animal studies show significant harmful effects from short-term exposure to CPA at low doses. Grower and industry confidence in this approach must be preserved through transparency.
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57
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Lichtenberg J, Pedersen P, Elvig-Joergensen S, Skov L, Olsen C, Glitsoe L. Toxicological studies on a novel phytase expressed from synthetic genes in Aspergillus oryzae. Regul Toxicol Pharmacol 2011; 60:401-10. [DOI: 10.1016/j.yrtph.2011.05.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 05/22/2011] [Accepted: 05/24/2011] [Indexed: 11/27/2022]
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58
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Abbas HK, Weaver MA, Horn BW, Carbone I, Monacell JT, Shier WT. Selection ofAspergillus flavusisolates for biological control of aflatoxins in corn. TOXIN REV 2011. [DOI: 10.3109/15569543.2011.591539] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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59
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Miller CD, Osweiler GD, Richard JL, Meador VP. Morphological and hematological changes in young turkey poults acutely exposed to cyclopiazonic acid. TOXIN REV 2011. [DOI: 10.3109/15569543.2011.590784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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60
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Abbas H, Zablotowicz R, Horn B, Phillips N, Johnson B, Jin X, Abel C. Comparison of major biocontrol strains of non-aflatoxigenicAspergillus flavusfor the reduction of aflatoxins and cyclopiazonic acid in maize. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2011; 28:198-208. [DOI: 10.1080/19440049.2010.544680] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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62
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63
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64
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Ortín I, González JF, de la Cuesta E, Avendaño C. Synthesis of tetramic acids with a benzo[f]indolizine skeleton. Transannular rearrangements in pyrazino[1,2-b]isoquinolin-4-ones. Tetrahedron 2010. [DOI: 10.1016/j.tet.2010.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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65
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Malekinejad H, Akbari P, Allymehr M, Hobbenaghi R, Rezaie A. Cyclopiazonic acid augments the hepatic and renal oxidative stress in broiler chicks. Hum Exp Toxicol 2010; 30:910-9. [DOI: 10.1177/0960327110384285] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Generation of reactive oxygen species (ROS) leads to serious tissue injuries. The effect of cyclopiazonic acid (CPA) on oxidative stress markers in the liver and kidneys of broiler chicks was studied. Ten-day-old male broiler chicks (Ross 308) were assigned into the control and test groups, which received normal saline and 10, 25, and 50 μg/kg CPA, respectively, for 28 days. Body weight gain, serum level of alkaline phosphatase (ALP), γ-glutamyl transferase (GGT), uric acid, creatinine, and blood urea nitrogen (BUN) were measured after 2 and 4 weeks exposure. Moreover, the total thiol molecules (TTM) and malondialdehyde (MDA) content of the liver and kidneys were assessed. No significant differences (p > 0.05) were found in body weight gain between the control and test groups. Whereas, the hepatic weight increased significantly (p < 0.05) in animals that received 25 and 50 μg/kg CPA. Both ALP and GGT level in serum were elevated in comparison to the control group. CPA also resulted in uric acid, creatinine, and BUN enhancement in broilers. The MDA content of the liver and kidneys showed remarkable increase. By contrast, the TTM levels in the liver and kidneys were significantly (p < 0.05) attenuated. Histopathological findings confirmed the biochemical changes in either organ characterized by inflammatory cells infiltration along with severe congestion and cell swelling, suggesting an inflammatory response. These data suggest that exposure to CPA resulted in hepatic and renal disorders, which were reflected as biochemical markers alteration and pathological injuries in either organ. The biochemical alteration and pathological abnormalities may be attributed to CPA-induced oxidative stress.
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Affiliation(s)
- H. Malekinejad
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran,
| | - P. Akbari
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - M. Allymehr
- Department of Poultry Diseases, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - R. Hobbenaghi
- Department of Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - A. Rezaie
- Department of Pharmacology and Toxicology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
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66
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Martos P, Thompson W, Diaz G. Multiresidue mycotoxin analysis in wheat, barley, oats, rye and maize grain by high-performance liquid chromatography-tandem mass spectrometry. WORLD MYCOTOXIN J 2010. [DOI: 10.3920/wmj2010.1212] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A method has been developed for the simultaneous analysis of 22 mycotoxins in wheat, barley, oats, rye and maize grain. Analysis is carried out with liquid chromatography-electrospray ionisation tandem mass spectrometry. The compounds included in this analysis are aflatoxins, sterigmatocystin, cyclopiazonic acid, tricothecenes, ochratoxin A, fumonisins, zearalonone, and ergot alkaloids. Sample extraction (2 g) with acetonitrile:water (8 ml, 80:20) was carried out for 2 min using a commercial sample preparation apparatus (Stomacher®). The extract was then centrifuged, filtered and analysed. Extraction of fumonisins from maize (2 g) was optimised by first extracting the maize with acetonitrile: water (5 ml, 80:20) followed by the addition of water (3 ml), which permitted extraction of the 22 mycotoxins, including the fumonisins. Chromatography was carried out with a minicolumn (7.5×2.1 mm, 5 µm) (5 µl sample injection) and in 11 min, including column reconditioning. Analysis was carried out with 2 MRM transitions for the precursor ions. All method detection limits were below current maximum Canadian residue limits. Matrix effects for each compound in each of the 5 matrices were estimated and ranged from 70 to 149%, but most were 100±10%. Accuracy, repeatability and ruggedness were established. Proficiency samples from FERA (Food and Environment Research Agency, Sand Hutton, York, UK) were tested and are reported. Finally, 100 field samples of the various grains were tested with this method and are reported with the observation of numerous mycotoxins in all matrices, including ergotamine in winter wheat.
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Affiliation(s)
- P. Martos
- Laboratory Services Division, University of Guelph, 95 Stone Rd. W., Guelph, Ontario N1H 8J7, Canada
| | - W. Thompson
- Laboratory Services Division, University of Guelph, 95 Stone Rd. W., Guelph, Ontario N1H 8J7, Canada
| | - G. Diaz
- Laboratorio de Toxicología, Facultad de Medicina Veterinaria y de Zootecnia, Universidad Nacional de Colombia, Bogotá, D.C., Colombia
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67
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Rohm B, Scherlach K, Möbius N, Partida-Martinez LP, Hertweck C. Toxin production by bacterial endosymbionts of a Rhizopus microsporus strain used for tempe/sufu processing. Int J Food Microbiol 2010; 136:368-71. [PMID: 19942312 DOI: 10.1016/j.ijfoodmicro.2009.10.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 10/01/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
Abstract
Mould fungi are not only well known for food spoilage through toxin formation but also for the production of fermented foods. In Asian countries, the fermentation of soy beans and tofu for tempe and sufu production with various Rhizopus strains is widespread. Here we report the finding of toxinogenic bacteria in a starter culture used for sufu production. By means of metabolic profiling of the fungus under standard conditions for tempe and sufu production, we found that toxins of the rhizoxin complex are produced in critical amounts. Considering that rhizoxins are severe toxins with strong antimitotic activity it is important to notice that our findings uncover a health-threatening symbiosis in food processing. A simple PCR method for detecting toxinogenic endofungal bacteria in starter cultures is proposed.
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Affiliation(s)
- Barbara Rohm
- Leibniz Institute for Natural Product Research and Infection Biology (HKI), Dept. of Biomolecular Chemistry, Beutenbergstr. 11a, 07745 Jena, Germany
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68
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Chang PK, Ehrlich KC, Fujii I. Cyclopiazonic acid biosynthesis of Aspergillus flavus and Aspergillus oryzae. Toxins (Basel) 2009; 1:74-99. [PMID: 22069533 PMCID: PMC3202784 DOI: 10.3390/toxins1020074] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 11/03/2009] [Accepted: 11/04/2009] [Indexed: 12/19/2022] Open
Abstract
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 what is currently known about the toxicity of CPA to animals and humans, both by itself or in combination with other mycotoxins. The review also discusses CPA biosynthesis and the genetic diversity of CPA production in A. flavus/oryzae populations.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA; (K.E.)
| | - Kenneth C. Ehrlich
- Southern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA; (K.E.)
| | - Isao Fujii
- School of Pharmacy, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba, Iwate 028-3694, Japan; (I.F.)
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69
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Moore GG, Singh R, Horn BW, Carbone I. Recombination and lineage-specific gene loss in the aflatoxin gene cluster of Aspergillus flavus. Mol Ecol 2009; 18:4870-87. [PMID: 19895419 DOI: 10.1111/j.1365-294x.2009.04414.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aflatoxins produced by Aspergillus flavus are potent carcinogens that contaminate agricultural crops. Recent efforts to reduce aflatoxin concentrations in crops have focused on biological control using nonaflatoxigenic A. flavus strains AF36 (=NRRL 18543) and NRRL 21882 (the active component of afla-guard. However, the evolutionary potential of these strains to remain nonaflatoxigenic in nature is unknown. To elucidate the underlying population processes that influence aflatoxigenicity, we examined patterns of linkage disequilibrium (LD) spanning 21 regions in the aflatoxin gene cluster of A. flavus. We show that recombination events are unevenly distributed across the cluster in A. flavus. Six distinct LD blocks separate late pathway genes aflE, aflM, aflN, aflG, aflL, aflI and aflO, and there is no discernable evidence of recombination among early pathway genes aflA, aflB, aflC, aflD, aflR and aflS. The discordance in phylogenies inferred for the aflW/aflX intergenic region and two noncluster regions, tryptophan synthase and acetamidase, is indicative of trans-species evolution in the cluster. Additionally, polymorphisms in aflW/aflX divide A. flavus strains into two distinct clades, each harbouring only one of the two approved biocontrol strains. The clade with AF36 includes both aflatoxigenic and nonaflatoxigenic strains, whereas the clade with NRRL 21882 comprises only nonaflatoxigenic strains and includes all strains of A. flavus missing the entire gene cluster or with partial gene clusters. Our detection of LD blocks in partial clusters indicates that recombination may have played an important role in cluster disassembly, and multilocus coalescent analyses of cluster and noncluster regions indicate lineage-specific gene loss in A. flavus. These results have important implications in assessing the stability of biocontrol strains in nature.
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Affiliation(s)
- Geromy G Moore
- Center for Integrated Fungal Research, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
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70
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Abstract
Bone problems are a major threat in meat-type and breeder poultry globally, raising both welfare and economic concerns. Leg weakness is multifactorial in origin and can be influenced by management, genetics, environment, nutrition and mycotoxins. Various mycotoxins, singly and severally, are known to exert an adverse effect on bone metabolism leading to leg weakness. Leg weakness in poultry as caused by mycotoxins and its alleviation is reviewed.
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Affiliation(s)
- G. Devegowda
- Division of Animal Sciences, University of Agricultural Sciences, Hebbal, Bangalore 560024, India
| | - D. Ravikiran
- Department of Poultry Science, Karnataka Veterinary, Animal and Fishery Sciences University, Hebbal, Bangalore 560024, India
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71
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Abstract
Aspergillus flavus is the major producer of carcinogenic aflatoxins in crops worldwide and is also an important opportunistic human pathogen in aspergillosis. The sexual state of this heterothallic fungus is described from crosses between strains of the opposite mating type. Sexual reproduction occurred between sexually compatible strains belonging to different vegetative compatibility groups. Multiple, indehiscent ascocarps containing asci and ascospores formed within the pseudoparenchymatous matrix of stromata, which places the fungus in genus Petromyces. The teleomorph of P. flavus could not be distinguished from that of P. parasiticus (anamorph = A. parasiticus), another aflatoxin-producing species, based on morphology of the sexual structures. The two species can be separated by anamorph morphology, mycotoxin profile and molecular characters.
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Affiliation(s)
- Bruce W Horn
- National Peanut Research Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Dawson, Georgia 39842, USA.
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72
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Abstract
Cyclopiazonic acid (CPA) is a mycotoxin produced by some of the same species of fungi that produce the more widely known aflatoxins. As a consequence it has been found previously that CPA and the aflatoxins may co-occur in commodities under certain conditions. CPA, which is a substituted indole, has a chromophore with absorptions in the ultraviolet (UV) region (223 nm, 278 nm). Quantification of CPA is commonly accomplished by liquid chromatographic separation followed by detection of one of the UV absorbances. CPA has not previously been described as fluorescent, and it likely is not. However, herein we report that, following exposure to high intensity UV light in a photochemical reactor, fluorescent products of CPA are produced. In methanol or aqueous acetonitrile these products have an excitation maximum of 372 nm and an emission maximum of 462 nm. Upon exposure to UV light for extended periods a decrease in the absorbance of CPA at 223 nm and 278 nm and a concomitant increase in fluorescence was observed. CPA and aflatoxin B1 were separated by reverse-phase liquid chromatography and the eluant was subjected to post-column photolysis, which allowed the fluorescence detection of both toxins. The ability to photolyse CPA and detect this toxin by fluorescence may open up new avenues for determination of this mycotoxin alone or together with the aflatoxins.
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Affiliation(s)
- C. Maragos
- Mycotoxin Research Unit, National Center for Agricultural Utilization Research, ARS, USDA, 1815 N. University Street, Peoria, IL 61604, USA
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73
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Chang PK, Horn BW, Dorner JW. Clustered genes involved in cyclopiazonic acid production are next to the aflatoxin biosynthesis gene cluster in Aspergillus flavus. Fungal Genet Biol 2009; 46:176-82. [DOI: 10.1016/j.fgb.2008.11.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 11/07/2008] [Accepted: 11/07/2008] [Indexed: 11/26/2022]
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74
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Dorner JW. Management and prevention of mycotoxins in peanuts. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2008; 25:203-8. [PMID: 18286410 DOI: 10.1080/02652030701658357] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Contamination of peanuts with mycotoxins, particularly aflatoxins, is a worldwide problem that affects both food safety and agricultural economies. Most countries have adopted regulations that limit the quantity of aflatoxins in food and feed to 20 microg kg(-1) or less; however, environmental conditions in most of the world where peanuts are produced and stored often make it difficult or impossible to attain such low concentrations. In addition to aflatoxins, peanuts are often contaminated with cyclopiazonic acid (CPA). Both mycotoxins are produced by Aspergillus flavus, a ubiquitous fungus that can infect and grow in peanuts under both pre- and post-harvest conditions. Management of mycotoxin contamination in peanuts generally involves removal of high-risk components from shelled lots or the removal of individual, highly contaminated nuts. This is accomplished by various processes such as screening, kernel sizing, electronic colour sorting, hand sorting, and blanching followed by electronic colour sorting. Recently, biological control technology has been developed that prevents much of the contamination that might otherwise occur. Biocontrol is based on competitive exclusion whereby a dominant population of a non-toxigenic strain of A. flavus is established in the soil before peanuts are subjected to conditions favouring contamination. The applied strain competes with toxigenic strains for infection sites, resulting in significantly reduced concentrations of aflatoxins in peanuts. Monitoring of the first commercial use of the technology showed that aflatoxins were reduced by an average of 85% in farmers' stock peanuts and by as much as 98% in shelled, edible grade peanuts.
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Affiliation(s)
- J W Dorner
- USDA, ARS, National Peanut Research Laboratory, Dawson, GA, USA.
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75
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Abbas H, Zablotowicz R, Bruns H. Modelling the colonisation of maize by toxigenic and non-toxigenic Aspergillus flavus strains: implications for biological control. WORLD MYCOTOXIN J 2008. [DOI: 10.3920/wmj2008.x036] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To successfully exploit biological control it is desirable to understand how the introduced agent colonises the host and interferes with establishment of the pest. This study assessed field colonisation of maize by Aspergillus flavus strains as biological control agents to reduce aflatoxin contamination. Maize (corn, Zea mays L.) ears were inoculated with A. flavus using a pin-bar technique in 2004 and 2005. Non-aflatoxigenic strains K49 (NRRL 30797) & CT3 (NRRL 30798) and toxigenic F3W4 (NRRL 30798) were compared against a carrier control (0.2% aqueous Tween 20). Ten ears were sampled over 12 to 20 days, visually assessed, and curves fit to a three compartment Gompertz equation or other best appropriate regressions. Aflatoxin was determined by HPLC and cyclopiazonic acid (CPA) by LC/MS. The Gompertz model describes growth parameters, e.g. growth constant, lag phase and maximum colonisation characterised patterns of maize colonisation for most inoculated treatments. Aflatoxin accumulation in maize inoculated with F3W4 was about 35,000 ng/g in 2004 and 2005, with kinetics of aflatoxin accumulation in 2005 well described by the Gompertz equation. Less than 200 ng/g was observed in maize inoculated with strains CT3 & K49 and accumulation was described by a linear or logistic model. Maize inoculated with strains CT3 and F3W4 accumulated a maximum of 220 and 169 µg/kg CPA, respectively, compared to 22 and 0.2 µg/kg in the control and K49 inoculated, respectively. This technique can be used to elucidate colonisation potential of non-toxigenic A. flavus in maize in relation to biological control of aflatoxin. The greatest reduction of aflatoxin and CPA in maize inoculated with strain K49 and Gompertz parameters on colonisation indicates its superiority to CT3 as a biological control agent. The dynamics of maize colonisation by A. flavus strains and subsequent mycotoxin accumulation generated by using the pin-bar technique has implications for characterising the competence of biocontrol strains for reducing aflatoxin contamination.
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Affiliation(s)
- H. Abbas
- USDA-Agricultural Research Service, Crop Genetics & Production Research Unit, Post Office Box 345, Stoneville, MS 38776, USA
| | - R. Zablotowicz
- USDA-Agricultural Research Service, Southern Weed Science Research Unit, Post Office Box 350, Stoneville, MS 38776, USA
| | - H. Bruns
- USDA-Agricultural Research Service, Crop Genetics & Production Research Unit, Post Office Box 345, Stoneville, MS 38776, USA
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76
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Lin ZJ, Lu ZY, Zhu TJ, Fang YC, Gu QQ, Zhu WM. Penicillenols from Penicillium sp. GQ-7, an Endophytic Fungus Associated with Aegiceras corniculatum. Chem Pharm Bull (Tokyo) 2008; 56:217-21. [DOI: 10.1248/cpb.56.217] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Zhen-Jian Lin
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
| | - Zhen-Yu Lu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
| | - Tian-Jiao Zhu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
| | - Yu-Chun Fang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
| | - Qian-Qun Gu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
| | - Wei-Ming Zhu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China
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77
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R. Katritzky A, S. Vincek A, J. Steel P. Triphenylphosphoranylidene Substituted Heterocycles as Versatile Intermediates. HETEROCYCLES 2008. [DOI: 10.3987/com-08-s(f)12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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78
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Monaci L, Vatinno R, De Benedetto GE. Fast detection of cyclopiazonic acid in cheese using Fourier transform mid-infrared ATR spectroscopy. Eur Food Res Technol 2007. [DOI: 10.1007/s00217-006-0428-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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79
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Olempska-Beer ZS, Merker RI, Ditto MD, DiNovi MJ. Food-processing enzymes from recombinant microorganisms--a review. Regul Toxicol Pharmacol 2006; 45:144-158. [PMID: 16769167 DOI: 10.1016/j.yrtph.2006.05.001] [Citation(s) in RCA: 152] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Indexed: 11/17/2022]
Abstract
Enzymes are commonly used in food processing and in the production of food ingredients. Enzymes traditionally isolated from culturable microorganisms, plants, and mammalian tissues are often not well-adapted to the conditions used in modern food production methods. The use of recombinant DNA technology has made it possible to manufacture novel enzymes suitable for specific food-processing conditions. Such enzymes may be discovered by screening microorganisms sampled from diverse environments or developed by modification of known enzymes using modern methods of protein engineering or molecular evolution. As a result, several important food-processing enzymes such as amylases and lipases with properties tailored to particular food applications have become available. Another important achievement is improvement of microbial production strains. For example, several microbial strains recently developed for enzyme production have been engineered to increase enzyme yield by deleting native genes encoding extracellular proteases. Moreover, certain fungal production strains have been modified to reduce or eliminate their potential for production of toxic secondary metabolites. In this article, we discuss the safety of microorganisms used as hosts for enzyme-encoding genes, the construction of recombinant production strains, and methods of improving enzyme properties. We also briefly describe the manufacture and safety assessment of enzyme preparations and summarize options for submitting information on enzyme preparations to the US Food and Drug Administration.
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Affiliation(s)
- Zofia S Olempska-Beer
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Food Additive Safety, HFS-255, 5100 Paint Branch Parkway, College Park, MD 20740, USA.
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80
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Abstract
This article reviews the curious history of kojic acid, discovered as a fungal natural product in 1907. It was one of the first secondary metabolites to have its biosynthetic pathway studied by the isotope tracer technique, and, more recently, has been of interest as a skin lightening agent. There are 112 references.
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Affiliation(s)
- Ronald Bentley
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA
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81
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Bamba R, Sumbali G. Co-occurrence of aflatoxin B1 and cyclopiazonic acid in sour lime (Citrus aurantifolia Swingle) during post-harvest pathogenesis by Aspergillus flavus. Mycopathologia 2005; 159:407-11. [PMID: 15883727 DOI: 10.1007/s11046-004-8401-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2003] [Accepted: 01/25/2004] [Indexed: 10/25/2022]
Abstract
During hot and humid seasons, extensive rot of sour lime was observed to be caused by Aspergillus flavus. In view of this, investigations were undertaken to obtain data on the production of various toxins by A. flavus during post harvest pathogenesis of sour lime. Sixty percent of the pathogenic A. flavus isolates were detected to be aflatoxin B(1) producers in sour lime tissue. It was also noted that thirty three percent of aflatoxigenic A. flavus isolates had the potential to coproduce cyclopiazonic acid (CPA). Such aflatoxigenic isolates produced quantitatively more CPA (ranging from 250.0 to 2501.3 microg/kg) than aflatoxin B(1) (ranging from 141.3 to 811.7 microg/kg) in the affected sour lime. This study demonstrates for the first time that sour lime are a favourable substrate for aflatoxin B(1) and cyclopiazonic acid production by A. flavus isolates. This is of great concern to the health of consumers.
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Affiliation(s)
- Rozy Bamba
- Department of Botany, University of Jammu, Baba Saheb Ambedkar Road, Jammu 180006, India
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82
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Keblys M, Bernhoft A, Höfer CC, Morrison E, Larsen HJS, Flåøyen A. The effects of the Penicillium mycotoxins citrinin, cyclopiazonic acid, ochratoxin A, patulin, penicillic acid, and roquefortine C on in vitro proliferation of porcine lymphocytes. Mycopathologia 2004; 158:317-24. [PMID: 15702270 DOI: 10.1007/s11046-005-5523-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2003] [Accepted: 12/04/2003] [Indexed: 10/25/2022]
Abstract
The in vitro effect of each of the Penicillium mycotoxins citrinin (CIT), cyclopiazonic acid (CPA), ochratoxin A (OTA), patulin (PAT), penicillic acid (PIA) and roquefortine C (RQC) on mitogen induced lymphocyte proliferation was determined using purified lymphocytes from 6 piglets. Dose response curves for each mycotoxin were generated and the concentrations producing 50% inhibition of cell proliferation (IC(50)) were estimated. OTA and PAT were the most potent toxins with IC(50) of 1.3 and 1.2 micromol/l, respectively (0.52 and 0.18 mg/l, respectively). Based on molar concentrations, OTA was 15, 30, 40, and 65 times more potent as an inhibitor than PIA, CIT, CPA and RQC, respectively.
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Affiliation(s)
- Modestas Keblys
- National Veterinary Institute, P.O. Box 8156 Dep., N-0033, Oslo, Norway
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83
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Blumenthal CZ. Production of toxic metabolites in Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei: justification of mycotoxin testing in food grade enzyme preparations derived from the three fungi. Regul Toxicol Pharmacol 2004; 39:214-28. [PMID: 15041150 DOI: 10.1016/j.yrtph.2003.09.002] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2003] [Indexed: 11/23/2022]
Abstract
Aspergillus niger, Aspergillus oryzae, and Trichoderma reesei are three important production organisms used in industrial fermentations. Several of the fungal secondary metabolites produced by selected strains of these three fungi are capable of eliciting toxicity in animals. Among those toxic substances are the well-known mycotoxins 3-nitropropionic acid and ochratoxin A. However, many others, such as kojic acid, may not be true mycotoxins. The production, extraction, chemical structure, and the toxicity (expressed as LD(50)) of these substances are reviewed. Production of toxic secondary metabolites in A. niger, A. oryzae, and T. reesei is strain-specific and environment-dependent. Considering all of the safety measures taken in the industrial production process, these three fungal species are safe to use. The recently revised JECFA specification for mycotoxins in food enzyme preparations is also discussed. The extent of mycotoxin tests in food enzyme preparations should be judged on a case-by-case basis, through a careful evaluation based on knowledge of taxonomy, biochemistry, and genetics. In many cases, the testing scope at the level of genus should be sufficient. In other cases, the scope can even be further narrowed based on scientific knowledge and assessment.
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84
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Zeng QY, Wang XR, Blomquist G. Development of mitochondrial SSU rDNA-based oligonucleotide probes for specific detection of common airborne fungi. Mol Cell Probes 2003; 17:281-8. [PMID: 14602478 DOI: 10.1016/s0890-8508(03)00067-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this study we sequenced partial mitochondrial small subunit rDNA from 32 fungal strains representing 31 species from 16 genera. Most of these species are common airborne fungi and pathogens that may cause various public health concerns. Sequence alignment showed several conserved and highly variable regions. The variable regions were deployed to design oligonucleotide probes for each fungal species. The specificity of the designed probes was first examined through homology search against GenBank database then further verified through hybridization experiments to 38 fungal strains. A total of 23 probes were verified as specific to 15 fungal species commonly detected in living and working environments. These new probes will have potential applications in clinical diagnosis and public health-related environmental monitoring.
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Affiliation(s)
- Qing-Yin Zeng
- National Institute for Working Life, SE-90713 Umeå, Sweden
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85
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Dorner JW. Recent advances in analytical methodology for cyclopiazonic acid. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 504:107-16. [PMID: 11922080 DOI: 10.1007/978-1-4615-0629-4_11] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Cyclopiazonic acid (CPA) is a toxic indole tetramic acid that has been isolated from numerous species of Aspergillus and Penicillium. It has been found as a natural contaminant of cheese, corn, peanuts and various feedstuffs. Historically, thin-layer chromatography has been the most widely used method for quantitative determination of CPA in fungal cultures and agricultural commodities. Several liquid chromatographic (LC) and spectrophotometric methods have also been used, but these require extensive, time-consuming cleanup procedures to achieve accurate quantitation. More recently, enzyme-linked immunosorbent assays (ELISA) have been developed for quantification of CPA, and an immunoaffinity column (IAC) has been developed for cleanup of sample extracts prior to quantification by ELISA or LC. In applying the IAC to the cleanup of peanut extracts, recovery of CPA from spiked samples ranged from 83.7% to 90.8%, and the method was successfully applied to the analysis of peanuts that were naturally contaminated with CPA.
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Affiliation(s)
- Joe W Dorner
- USDA, ARS, National Peanut Research Laboratory, Dawson, GA 31742, USA
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86
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Affiliation(s)
- E J De Waal
- RIKILT-Wageningen University and Research Centre, Wageningen, The Netherlands
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87
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Brinch DS, Pedersen PB. Toxicological studies on Laccase from Myceliophthora thermophila expressed in Aspergillus oryzae. Regul Toxicol Pharmacol 2002; 35:296-307. [PMID: 12202045 DOI: 10.1006/rtph.2002.1538] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The bioindustrially produced enzyme laccase can be used in different technical and food applications to facilitate processes. It can be added to different oral care products such as mouthwash, toothpaste, mints, and gums to prevent halitosis. Laccase, produced by submerged fermentation of Aspergillus oryzae, containing a gene originating from Myceliophthora thermophila, was subject to a series of toxicological tests to document its safety in use. It was not found to be mutagenic in the Salmonella typhimurium reverse mutation assay, nor did it cause chromosomal aberrations in cultured human lymphocytes. No evidence of inhalation toxicity or skin and eye irritation was found. There was no evidence of possible skin sensitization in a human skin sensitization test when Laccase was tested at 10% (w/v): thus Laccase would appear to have a low skin sensitization potential. Oral administration to rats of up to 10.0 mL/kg body wt/day (equivalent to a total organic solids dosage of 1.72 g/kg body wt/day) for 13 weeks did not cause any adverse effect.
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Affiliation(s)
- D S Brinch
- Novozymes A/S, Krogshoejvej 36, DK-2880 Bagsvaerd, Denmark.
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88
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Brinch DS, Pedersen PB. Toxicological studies on Polyporus pinsitus laccase expressed by Aspergillus oryzae intended for use in food. FOOD ADDITIVES AND CONTAMINANTS 2002; 19:323-34. [PMID: 11962689 DOI: 10.1080/02652030110087456] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The laccase used in the study was produced by submerged fermentation of Aspergillus oryzae, containing a gene originating from Polyporus pinsitus. Laccase is to be employed as a processing aid in the juice industry to make a clear and stable juice. The enzyme was subject to a series of toxicological tests to document its safety in use. It was not mutagenic in the Salmonella typhimurium reverse mutation assay, and it did not cause chromosomal aberrations in cultured human lymphocytes. No evidence of inhalation toxicity or skin and eye irritation was found. Oral administration to rat of up to 10 ml kg(-1) b.w. day(-1) (equivalent to a total organic solids dosage of 676 mg kg(-1) b.w. day(-1) or a laccase dosage of 2601 LACU kg(-1) b.w. day(-1)) for 13 weeks did not cause any adverse effect. The maximum recommended dosage of laccase used for juice applications is 50 LACU l(-1) juice.
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