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Ashraf W, Rehman A, Rabbani M, Shaukat W, Wang JS. Aflatoxins posing threat to food safety and security in Pakistan: Call for a one health approach. Food Chem Toxicol 2023; 180:114006. [PMID: 37652127 DOI: 10.1016/j.fct.2023.114006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/26/2023] [Accepted: 08/26/2023] [Indexed: 09/02/2023]
Abstract
Aflatoxins are among the most important mycotoxins due to their widespread occurrence and adverse impacts on humans and animals. These toxins and/or their metabolites cannot be destroyed with cooking or boiling methods. Therefore, consumption of aflatoxin-contaminated food may lead to impaired growth, compromised immunity, stomach and liver cancer, and acute toxicity. These adverse effects along with food wastage might have detrimental consequences on a country's economy. Several studies from Pakistan reported a high prevalence of aflatoxins in food and feed commodities (Range; milk = 0.6-99.4%, cereals, and grains = 0.38-41%, animal feed = 31-100%). Notably, Pakistan reported very high figures of impaired child growth-stunted 40.2%, wasted 17.7% and underweight 28.9%-that could be associated with the higher aflatoxin prevalence in food items. Importantly, high aflatoxins prevalence, i.e. 100%, 69% and 60.5%, in children has been reported in Pakistan. Food and feed are more prone to aflatoxin contamination due to Pakistan's hot and humid climate; however, limited awareness, inadequate policy framework, and weak implementation mechanisms are the major obstacles to effective control. This review will discuss aflatoxins prevalence, associated risk factors, adverse health effects, required regulatory regime, and effective control strategies adopting the One Health approach to ensure food safety and security.
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Affiliation(s)
- Waseela Ashraf
- Department of Epidemiology and Public Health, University of Veterinary and Animal Sciences Lahore, 54000, Pakistan; Department of Environmental Health Science, The University of Georgia, Athens, GA, USA; Health Services Academy, Islamabad, 44000, Pakistan
| | - Abdul Rehman
- Department of Epidemiology and Public Health, University of Veterinary and Animal Sciences Lahore, 54000, Pakistan.
| | - Masood Rabbani
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Waseem Shaukat
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, Calgary, T2N4N1, Alberta, Canada
| | - Jia-Sheng Wang
- Department of Environmental Health Science, The University of Georgia, Athens, GA, USA
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Ortega-Beltran A, Bandyopadhyay R. Aflatoxin biocontrol in practice requires a multidisciplinary, long-term approach. FRONTIERS IN SUSTAINABLE FOOD SYSTEMS 2023. [DOI: 10.3389/fsufs.2023.1110964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
One of the most elusive food safety problems is the contamination of staple crops with the highly carcinogenic aflatoxins produced by Aspergillus section Flavi fungi. Governments, farmers, institutions, consumers, and companies demand aflatoxin solutions. Many aflatoxin management technologies exist, but their real-life use and effectiveness is determined by diverse factors. Biocontrol products based on atoxigenic isolates of A. flavus can effectively reduce aflatoxins from field to fork. However, development, testing, and registration of this technology is a laborious process. Further, several barriers prevent the sustainable use of biocontrol products. There are challenges to have the products accepted, to make them available at scale and develop mechanisms for farmers to buy them, to have the products correctly used, to demonstrate their value, and to link farmers to buyers of aflatoxin-safe crops. Developing an effective aflatoxin management technology is the first, major step. The second one, perhaps more complicated and unfortunately seldomly discussed, is to develop mechanisms to have it used at scale, sustainably, and converged with other complementary technologies. Here, challenges and actions to scale the aflatoxin biocontrol technology in several countries in sub-Saharan Africa are described with a view to facilitating aflatoxin management efforts in Africa and beyond.
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Pre-harvest strategy for reducing aflatoxin accumulation during storage of maize in Argentina. Int J Food Microbiol 2022; 380:109887. [DOI: 10.1016/j.ijfoodmicro.2022.109887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 08/03/2022] [Accepted: 08/22/2022] [Indexed: 11/21/2022]
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Application of Non-Aflatoxigenic Aspergillus flavus for the Biological Control of Aflatoxin Contamination in China. Toxins (Basel) 2022; 14:toxins14100681. [PMID: 36287950 PMCID: PMC9611986 DOI: 10.3390/toxins14100681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/18/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Biological control through the application of competitive non-aflatoxigenic Aspergillus flavus (A. flavus) to the soil during peanut growth is a practical method for controlling aflatoxin contamination. However, appropriate materials need to be found to reduce the cost of biocontrol products. In this study, a two-year experiment was conducted under field conditions in China, using a native non-aflatoxigenic strain to explore its effect. After three months of storage under high humidity, aflatoxin levels remained low in peanuts from fields treated with the biocontrol agent. Three types of substrates were tested with the biocontrol agent: rice grains, peanut meal (peanut meal fertilizer) and peanut coating. Compared to untreated fields, these formulations resulted in reductions of 78.23%, 67.54% and 38.48%, respectively. Furthermore, the ratios of non-aflatoxigenic A. flavus recovered in the soils at harvest in the treated fields were between 41.11% and 96.67% higher than that in untreated fields (25.00%), indicating that the rice inoculum was the most effective, followed by the peanut meal fertilizer and peanut coating. In 2019, the mean aflatoxin content of freshly harvested peanuts in untreated fields was 19.35 µg/kg higher than that in the fields treated with 7.5 kg/ha rice inoculum, which was 1.37 µg/kg. Moreover, no aflatoxin was detected in the two other plots treated with 10 and 15 kg/ha rice inoculum. This study showed that the native Chinese non-aflatoxigenic strain of A. flavus (18PAsp-zy1) had the potential to reduce aflatoxin contamination in peanuts. In addition, peanut meal can be used as an alternative substrate to replace traditional grains, reducing the cost of biocontrol products.
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Ability of Two Strains of Lactic Acid Bacteria To Inhibit Listeria monocytogenes by Spot Inoculation and in an Environmental Microbiome Context. Microbiol Spectr 2022; 10:e0101822. [PMID: 35852346 PMCID: PMC9431016 DOI: 10.1128/spectrum.01018-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We evaluated the ability of two strains of lactic acid bacteria (LAB) to inhibit L. monocytogenes using spot inoculation and environmental microbiome attached-biomass assays. LAB strains (PS01155 and PS01156) were tested for antilisterial activity toward 22 phylogenetically distinct L. monocytogenes strains isolated from three fruit packing environments (F1, F2, and F3). LAB strains were tested by spot inoculation onto L. monocytogenes lawns (108 and 107 CFU/mL) and incubated at 15, 20, 25, or 30°C for 3 days. The same LAB strains were also cocultured at 15°C for 3, 5, and 15 days in polypropylene conical tubes with L. monocytogenes and environmental microbiome suspensions collected from F1, F2, and F3. In the spot inoculation assay, PS01156 was significantly more inhibitory toward less concentrated L. monocytogenes lawns than more concentrated lawns at all the tested temperatures, while PS01155 was significantly more inhibitory toward less concentrated lawns only at 15 and 25°C. Furthermore, inhibition of L. monocytogenes by PS01156 was significantly greater at 15°C than higher temperatures, whereas the temperature did not have an effect on the inhibitory activity of PS01155. In the assay using attached environmental microbiome biomass, L. monocytogenes concentration was significantly reduced by PS01156, but not PS01155, when cocultured with microbiomes from F1 and F3 and incubated for 3 days at 15°C. Attached biomass microbiota composition was significantly affected by incubation time but not by LAB strain. This study demonstrates that LAB strains that may exhibit inhibitory properties toward L. monocytogenes in a spot inoculation assay may not maintain antilisterial activity within a complex microbiome. IMPORTANCEListeria monocytogenes has previously been associated with outbreaks of foodborne illness linked to consumption of fresh produce. In addition to conventional cleaning and sanitizing, lactic acid bacteria (LAB) have been studied for biocontrol of L. monocytogenes in food processing environments that are challenging to clean and sanitize. We evaluated whether two specific LAB strains, PS01155 and PS01156, can inhibit the growth of L. monocytogenes strains in a spot inoculation and in an attached-biomass assay, in which they were cocultured with environmental microbiomes collected from tree fruit packing facilities. LAB strains PS01155 and PS01156 inhibited L. monocytogenes in a spot inoculation assay, but the antilisterial activity was lower or not detected when they were grown with environmental microbiota. These results highlight the importance of conducting biocontrol challenge tests in the context of the complex environmental microbiomes present in food processing facilities to assess their potential for application in the food industry.
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Mamo FT, Shang B, Selvaraj JN, Zheng Y, Liu Y. Biocontrol efficacy of atoxigenic Aspergillus flavus strains against aflatoxin contamination in peanut field in Guangdong province, South China. Mycology 2022; 13:143-152. [PMID: 35711325 PMCID: PMC9196723 DOI: 10.1080/21501203.2021.1978573] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Application of atoxigenic strains of Aspergillus flavusto soils is the most successful aflatoxin biological control approach. The objective of this study was to evaluate the efficacies of native non-aflatoxin producing (atoxigenic) strains as a biocontrol agent in peanut field in China. The competitive atoxigenic A. flavus strains (JS4, SI1and SXN) isolated from different crops, in China were used for field evaluation. The strains applied during the growing season (June – October, 2016) in the field at rate of 25 kg inoculum/hectare. The colonization of these biocontrol agents has been investigated and the population of A. flavus communities in soil were determined. The incidences of toxin producing (toxigenic) A. flavus strains and aflatoxin contamination in peanuts were also determined. Treated plots produced significant reductions in the incidence of toxigenic isolates of A. flavus in soil. However, the total fungal densities were not significantly different (p > 0.05) after treatments. Large percentage of aflatoxin reductions, ranging from 82.8% (SXN) up to 87.2% (JS4) were recorded in treated plots. Generally, the results suggest that the strategy can be used to control aflatoxin contamination and continuous evaluation should be done.
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Affiliation(s)
- Firew Tafesse Mamo
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
- Ethiopian Biotechnology Institute, Addis Ababa, Ethiopia
| | - Bo Shang
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | | | - Yongquan Zheng
- State Key Laboratory for Biology Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Yang Liu
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
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Agbetiameh D, Ortega-Beltran A, Awuah RT, Atehnkeng J, Elzein A, Cotty PJ, Bandyopadhyay R. Field efficacy of two atoxigenic biocontrol products for mitigation of aflatoxin contamination in maize and groundnut in Ghana. BIOLOGICAL CONTROL : THEORY AND APPLICATIONS IN PEST MANAGEMENT 2020; 150:104351. [PMID: 33144821 PMCID: PMC7457722 DOI: 10.1016/j.biocontrol.2020.104351] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Biological control is one of the recommended methods for aflatoxin mitigation. Biocontrol products must be developed, and their efficacy demonstrated before widespread use. Efficacy of two aflatoxin biocontrol products, Aflasafe GH01 and Aflasafe GH02, were evaluated in 800 maize and groundnut farmers' fields during 2015 and 2016 in the Ashanti, Brong Ahafo, Northern, Upper East, and Upper West regions of Ghana. Both products were developed after an extensive examination of fungi associated with maize and groundnut in Ghana. Each product contains as active ingredient fungi four Aspergillus flavus isolates belonging to atoxigenic African Aspergillus Vegetative Compatibility Groups (AAVs) widely distributed across Ghana. An untreated field was maintained for each treated field to determine product efficacy. Proportions of atoxigenic AAVs composing each product were assessed in soils before product application, and soils and grains at harvest. Significant (P < 0.05) displacement of toxigenic fungi occurred in both crops during both years, in all five regions. Biocontrol-treated crops consistently had significantly (P < 0.05) less aflatoxins (range = 76% to 100% less; average = 99% less) than untreated crops. Results indicate that both biocontrol products are highly efficient, cost-effective, environmentally safe tools for aflatoxin mitigation. Most crops from treated fields could have been sold in both local and international food and feed premium markets. Adoption and use of biocontrol products have the potential to improve the health of Ghanaians, and both income and trade opportunities of farmers, aggregators, distributors, and traders.
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Affiliation(s)
- Daniel Agbetiameh
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Richard T. Awuah
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
| | - Abuelgasim Elzein
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
| | - Peter J. Cotty
- United States Department of Agriculture – Agricultural Research Service, Tucson, AZ 85721, USA
- School of Food Science and Engineering, Ocean University of China, Qingdao, China
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Zhang W, Chang X, Wu Z, Dou J, Yin Y, Sun C, Wu W. Rapid isolation of non-aflatoxigenic Aspergillus flavus strains. WORLD MYCOTOXIN J 2020. [DOI: 10.3920/wmj2019.2490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In the present study, a method for screening non-aflatoxigenic Aspergillus flavus in soil samples collected from major peanut-growing regions of China was developed. The single colonies were picked and cultured on Aspergillus flavus and parasiticus agar (AFPA). If the reverse side of the colony on AFPA was orange-coloured, it was considered A. flavus or Aspergillus parasiticus. After the genomic DNA of each strain was extracted, 28S rRNA and calmodulin were amplified and sequenced to determine the species. The key gene, aflR, was amplified and digested via polymerase chain reaction-restriction fragment length polymorphism. The aflatoxigenic A. flavus and the non-aflatoxigenic A. flavus and A. parasiticus were distinguished by enzyme digestion of aflR. 156 strains of A. flavus were screened, which consisted of 135 aflatoxigenic and 21 non-aflatoxigenic strains. The aflatoxin producing ability of each strain was confirmed using solid-state fermentation experiments. Using the method developed in the present study, we confirmed that the non-aflatoxigenic A. flavus strains isolated lost their capacity to produce aflatoxins. Considering there could be some alterations in other functional genes, some non-aflatoxigenic strains could be identified inaccurately as aflatoxigenic strains, although that did not occur in the present study. The growth of non-aflatoxigenic A. flavus was observed, and the most rapidly growing non-aflatoxigenic strain was selected for plate confrontation assays and toxic mixed culture experiments. The inhibition rate of non-aflatoxigenic A. flavus against aflatoxigenic A. flavus was 55.4 and 72.6% in potato dextrose agar (PDA) plate and natural soybean medium, respectively. The screened non-aflatoxigenic A. flavus strains provide a microbial resource for biological control of aflatoxin contamination.
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Affiliation(s)
- W. Zhang
- Department of Biological and Agricultural Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130022, China P.R
- Academy of National Food and Strategic Reserves Administration P.R.C, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing 100037, China P.R
| | - X. Chang
- Academy of National Food and Strategic Reserves Administration P.R.C, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing 100037, China P.R
| | - Z. Wu
- Department of Biological and Agricultural Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130022, China P.R
| | - J. Dou
- Department of Biological and Agricultural Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130022, China P.R
| | - Y. Yin
- Academy of National Food and Strategic Reserves Administration P.R.C, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing 100037, China P.R
| | - C. Sun
- Academy of National Food and Strategic Reserves Administration P.R.C, No.11 Baiwanzhuang Avenue, Xicheng District, Beijing 100037, China P.R
| | - W. Wu
- Department of Biological and Agricultural Engineering, Jilin University, No. 5988 Renmin Street, Changchun 130022, China P.R
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Soni P, Gangurde SS, Ortega-Beltran A, Kumar R, Parmar S, Sudini HK, Lei Y, Ni X, Huai D, Fountain JC, Njoroge S, Mahuku G, Radhakrishnan T, Zhuang W, Guo B, Liao B, Singam P, Pandey MK, Bandyopadhyay R, Varshney RK. Functional Biology and Molecular Mechanisms of Host-Pathogen Interactions for Aflatoxin Contamination in Groundnut ( Arachis hypogaea L.) and Maize ( Zea mays L.). Front Microbiol 2020; 11:227. [PMID: 32194520 PMCID: PMC7063101 DOI: 10.3389/fmicb.2020.00227] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/30/2020] [Indexed: 12/26/2022] Open
Abstract
Aflatoxins are secondary metabolites produced by soilborne saprophytic fungus Aspergillus flavus and closely related species that infect several agricultural commodities including groundnut and maize. The consumption of contaminated commodities adversely affects the health of humans and livestock. Aflatoxin contamination also causes significant economic and financial losses to producers. Research efforts and significant progress have been made in the past three decades to understand the genetic behavior, molecular mechanisms, as well as the detailed biology of host-pathogen interactions. A range of omics approaches have facilitated better understanding of the resistance mechanisms and identified pathways involved during host-pathogen interactions. Most of such studies were however undertaken in groundnut and maize. Current efforts are geared toward harnessing knowledge on host-pathogen interactions and crop resistant factors that control aflatoxin contamination. This study provides a summary of the recent progress made in enhancing the understanding of the functional biology and molecular mechanisms associated with host-pathogen interactions during aflatoxin contamination in groundnut and maize.
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Affiliation(s)
- Pooja Soni
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sunil S. Gangurde
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rakesh Kumar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sejal Parmar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Hari K. Sudini
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Yong Lei
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Xinzhi Ni
- Crop Genetics and Breeding Research Unit, United States Department of Agriculture – Agriculture Research Service, Tifton, GA, United States
| | - Dongxin Huai
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Jake C. Fountain
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
| | - Samuel Njoroge
- International Crops Research Institute for the Semi-Arid Tropics, Lilongwe, Malawi
| | - George Mahuku
- International Institute of Tropical Agriculture, Dar es Salaam, Tanzania
| | | | - Weijian Zhuang
- Oil Crops Research Institute, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Baozhu Guo
- Crop Protection and Management Research Unit, United States Department of Agriculture – Agricultural Research Service, Tifton, GA, United States
| | - Boshou Liao
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Prashant Singam
- Department of Genetics, Osmania University, Hyderabad, India
| | - Manish K. Pandey
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rajeev K. Varshney
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
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Feng J, Dou J, Zhang Y, Wu Z, Yin D, Wu W. Thermosensitive Hydrogel for Encapsulation and Controlled Release of Biocontrol Agents to Prevent Peanut Aflatoxin Contamination. Polymers (Basel) 2020; 12:E547. [PMID: 32138229 PMCID: PMC7182945 DOI: 10.3390/polym12030547] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 12/11/2022] Open
Abstract
Starch, alginate, and poly(N-isopropylacrylamide) (PNIPAAm) were combined to prepare a semi-interpenetrating network (IPN) hydrogel with temperature sensitivity. Calcium chloride was used as cross-linking agent, the non-toxigenic Aspergillus flavus spores were successfully encapsulated as biocontrol agents by the method of ionic gelation. Characterization of the hydrogel was performed by Fourier-transform infrared spectroscopy (FTIR), scanning electron micrograph (SEM), and thermogravimetry analysis (TGA). Formulation characteristics, such as entrapment efficiency, beads size, swelling behavior, and rheological properties were evaluated. The optical and rheological measurements indicated that the lower critical solution temperature (LCST) of the samples was about 29-30 °C. TGA results demonstrated that the addition of kaolin could improve the thermal stability of the semi-IPN hydrogel. Morphological analysis showed a porous honeycomb structure on the surface of the beads. According to the release properties of the beads, the semi-IPN hydrogel beads containing kaolin not only have the effect of slow release before peanut flowering, but they also can rapidly release biocontrol agents after flowering begins. The early flowering stage of the peanut is the critical moment to apply biocontrol agents. Temperature-sensitive hydrogel beads containing kaolin could be considered as carriers of biocontrol agents for the control of aflatoxin in peanuts.
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Affiliation(s)
| | | | | | | | | | - Wenfu Wu
- Department of Biological and Agricultural Engineering, Jilin University, Changchun 130000, China; (J.F.); (J.D.); (Y.Z.); (Z.W.); (D.Y.)
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Senghor LA, Ortega-Beltran A, Atehnkeng J, Callicott KA, Cotty PJ, Bandyopadhyay R. The Atoxigenic Biocontrol Product Aflasafe SN01 Is a Valuable Tool to Mitigate Aflatoxin Contamination of Both Maize and Groundnut Cultivated in Senegal. PLANT DISEASE 2020; 104:510-520. [PMID: 31790640 DOI: 10.1094/pdis-03-19-0575-re] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Aflatoxin contamination of groundnut and maize infected by Aspergillus section Flavi fungi is common throughout Senegal. The use of biocontrol products containing atoxigenic Aspergillus flavus strains to reduce crop aflatoxin content has been successful in several regions, but no such products are available in Senegal. The biocontrol product Aflasafe SN01 was developed for use in Senegal. The four active ingredients of Aflasafe SN01 are atoxigenic A. flavus genotypes native to Senegal and distinct from active ingredients used in other biocontrol products. Efficacy tests on groundnut and maize in farmers' fields were carried out in Senegal during the course of 5 years. Active ingredients were monitored with vegetative compatibility analyses. Significant (P < 0.05) displacement of aflatoxin producers occurred in all years, districts, and crops. In addition, crops from Aflasafe SN01-treated fields contained significantly (P < 0.05) fewer aflatoxins both at harvest and after storage. Most crops from treated fields contained aflatoxin concentrations permissible in both local and international markets. Results suggest that Aflasafe SN01 is an effective tool for aflatoxin mitigation in groundnut and maize. Large-scale use of Aflasafe SN01 should provide health, trade, and economic benefits for Senegal.[Formula: see text] Copyright © 2020 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- L A Senghor
- La Direction de Protection Végétaux, BP20054 Dakar, Senegal
| | - A Ortega-Beltran
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | - J Atehnkeng
- Chitedze Research Station, International Institute of Tropical Agriculture, Lilongwe, Malawi
| | - K A Callicott
- U.S. Department of Agriculture-Agricultural Research Service, School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, U.S.A
| | - P J Cotty
- U.S. Department of Agriculture-Agricultural Research Service, School of Plant Sciences, The University of Arizona, Tucson, AZ 85721, U.S.A
| | - R Bandyopadhyay
- International Institute of Tropical Agriculture, Ibadan, Nigeria
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Sarrocco S, Mauro A, Battilani P. Use of Competitive Filamentous Fungi as an Alternative Approach for Mycotoxin Risk Reduction in Staple Cereals: State of Art and Future Perspectives. Toxins (Basel) 2019; 11:E701. [PMID: 31810316 PMCID: PMC6950288 DOI: 10.3390/toxins11120701] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/27/2019] [Accepted: 11/29/2019] [Indexed: 12/23/2022] Open
Abstract
Among plant fungal diseases, those affecting cereals represent a huge problem in terms of food security and safety. Cereals, such as maize and wheat, are very often targets of mycotoxigenic fungi. The limited availability of chemical plant protection products and physical methods to control mycotoxigenic fungi and to reduce food and feed mycotoxin contamination fosters alternative approaches, such as the use of beneficial fungi as an active ingredient of biological control products. Competitive interactions, including both exploitation and interference competition, between pathogenic and beneficial fungi, are generally recognized as mechanisms to control plant pathogens populations and to manage plant diseases. In the present review, two examples concerning the use of competitive beneficial filamentous fungi for the management of cereal diseases are discussed. The authors retrace the history of the well-established use of non-aflatoxigenic isolates of Aspergillus flavus to prevent aflatoxin contamination in maize and give an overview of the potential use of competitive beneficial filamentous fungi to manage Fusarium Head Blight on wheat and mitigate fusaria toxin contamination. Although important steps have been made towards the development of microorganisms as active ingredients of plant protection products, a reasoned revision of the registration rules is needed to significantly reduce the chemical based plant protection products in agriculture.
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Affiliation(s)
- Sabrina Sarrocco
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy;
| | - Antonio Mauro
- International Institute of Tropical Agriculture, P.O. Box 34441 Dar es Salaam, Tanzania;
| | - Paola Battilani
- Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy
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Lagogianni CS, Tsitsigiannis DI. Effective Biopesticides and Biostimulants to Reduce Aflatoxins in Maize Fields. Front Microbiol 2019; 10:2645. [PMID: 31824451 PMCID: PMC6881375 DOI: 10.3389/fmicb.2019.02645] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/30/2019] [Indexed: 11/16/2022] Open
Abstract
The presence of ear rots in maize caused by Aspergillus flavus that are also associated with the production of aflatoxins has evolved into an increasing problem over the last few years. Since no commercial biological control products are still available to control A. flavus in maize in Europe, this study targets to the evaluation of six biopesticides/biostimulants (Botector®, Mycostop®, Serenade Max®, Trianum®, Vacciplant®, and zeolite) for the control of A. flavus and the derived aflatoxins in in vitro and maize field bioassays. Mycostop®, Serenade Max®, Vacciplant®, and zeolite reduced significantly A. flavus conidia production by 38.8–63.1%, and most of them were able to reduce aflatoxin B1 (AFB1) production in laboratory studies. Mycostop®, Trianum®, and Botector® were effective in reducing AFB1, in vitro. In the field, Mycostop® and Botector® treatments resulted in significant reduction of the disease severity (16.5 and 21.9%, respectively) and decreased significantly AFB1 content in maize kernels by 43.05 and 43.09%, respectively. For the first time, these results demonstrated the potential of commercial non-chemical products to suppress disease symptoms and aflatoxin content caused by A. flavus in maize under laboratory and field conditions.
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Affiliation(s)
- Christina S Lagogianni
- Laboratory of Plant Pathology, Department of Crop Science, School of Plant Sciences, Agricultural University of Athens, Athens, Greece
| | - Dimitrios I Tsitsigiannis
- Laboratory of Plant Pathology, Department of Crop Science, School of Plant Sciences, Agricultural University of Athens, Athens, Greece
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14
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Bandyopadhyay R, Atehnkeng J, Ortega-Beltran A, Akande A, Falade TDO, Cotty PJ. "Ground-Truthing" Efficacy of Biological Control for Aflatoxin Mitigation in Farmers' Fields in Nigeria: From Field Trials to Commercial Usage, a 10-Year Study. Front Microbiol 2019; 10:2528. [PMID: 31824438 PMCID: PMC6882503 DOI: 10.3389/fmicb.2019.02528] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/21/2019] [Indexed: 01/09/2023] Open
Abstract
In sub-Saharan Africa (SSA), diverse fungi belonging to Aspergillus section Flavi frequently contaminate staple crops with aflatoxins. Aflatoxins negatively impact health, income, trade, food security, and development sectors. Aspergillus flavus is the most common causal agent of contamination. However, certain A. flavus genotypes do not produce aflatoxins (i.e., are atoxigenic). An aflatoxin biocontrol technology employing atoxigenic genotypes to limit crop contamination was developed in the United States. The technology was adapted and improved for use in maize and groundnut in SSA under the trademark Aflasafe. Nigeria was the first African nation for which an aflatoxin biocontrol product was developed. The current study includes tests to assess biocontrol performance across Nigeria over the past decade. The presented data on efficacy spans years in which a relatively small number of maize and groundnut fields (8-51 per year) were treated through use on circa 36,000 ha in commercially-produced maize in 2018. During the testing phase (2009-2012), fields treated during one year were not treated in the other years while during commercial usage (2013-2019), many fields were treated in multiple years. This is the first report of a large-scale, long-term efficacy study of any biocontrol product developed to date for a field crop. Most (>95%) of 213,406 tons of maize grains harvested from treated fields contained <20 ppb total aflatoxins, and a significant proportion (>90%) contained <4 ppb total aflatoxins. Grains from treated plots had preponderantly >80% less aflatoxin content than untreated crops. The frequency of the biocontrol active ingredient atoxigenic genotypes in grains from treated fields was significantly higher than in grains from control fields. A higher proportion of grains from treated fields met various aflatoxin standards compared to grains from untreated fields. Results indicate that efficacy of the biocontrol product in limiting aflatoxin contamination is stable regardless of environment and cropping system. In summary, the biocontrol technology allows farmers across Nigeria to produce safer crops for consumption and increases potential for access to premium markets that require aflatoxin-compliant crops.
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Affiliation(s)
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | | | | | | | - Peter J. Cotty
- Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
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15
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Dhanamjayulu P, Boga RB, Mehta A. Inhibition of aflatoxin B1 biosynthesis and down regulation of aflR and aflB genes in presence of benzimidazole derivatives without impairing the growth of Aspergillus flavus. Toxicon 2019; 170:60-67. [PMID: 31541640 DOI: 10.1016/j.toxicon.2019.09.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/11/2019] [Accepted: 09/17/2019] [Indexed: 12/13/2022]
Abstract
Aflatoxins are mutagenic secondary metabolites produced by certain ubiquitous saprophytic fungi. These contaminate agricultural crops and pose a serious health threat to humans and livestock all over the world. Benzimidazole and its derivatives are biologically active heterocyclic compounds known for their fungicidal activity. In the present study, second and sixth position substituted benzimidazole derivatives are tested for their antifungal and anti-aflatoxigenic activity. Aflatoxigenic strain of Aspergillus flavus cultured in Yeast extract sucrose (YES) medium as well as in rice in the presence and absence of test compounds. 2-(2-Furyl) benzimidazole (FBD) showed complete inhibition of fungal growth at 50 μg/mL. However, the polar derivatives of FBD viz. 6-NFBD, 6-AFBD, 6-CAFBD, and 6-CFBD did not impair the fungal growth but effectively inhibited aflatoxin B1 biosynthesis. Significant down-regulation of aflR gene involved in regulation and aflB structural gene for aflatoxin B1 biosynthesis was observed in presence of 6-NFBD. These benzimidazole derivatives also showed good anti-aflatoxigenic activity in rice, though the IC50 concentrations in rice were comparatively higher than those in YES medium. This study summarizes the most notable structure-activity relationship (SAR) of 2-(2-Furyl) benzimidazoles for anti-aflatoxigenic and anti-fungal activities. These molecules can be further studied for their applications in industrial fermentation processes vulnerable to mold growth and subsequent aflatoxin B1 synthesis like koji fermentation, cheese production, etc.
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Affiliation(s)
- P Dhanamjayulu
- Department of Integrative Biology, School of Bio sciences and Technology, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India
| | | | - Alka Mehta
- Department of Integrative Biology, School of Bio sciences and Technology, Vellore Institute of Technology, Vellore, 632014, Tamil Nadu, India.
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16
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Agbetiameh D, Ortega-Beltran A, Awuah RT, Atehnkeng J, Islam MS, Callicott KA, Cotty PJ, Bandyopadhyay R. Potential of Atoxigenic Aspergillus flavus Vegetative Compatibility Groups Associated With Maize and Groundnut in Ghana as Biocontrol Agents for Aflatoxin Management. Front Microbiol 2019; 10:2069. [PMID: 31555251 PMCID: PMC6743268 DOI: 10.3389/fmicb.2019.02069] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/22/2019] [Indexed: 11/24/2022] Open
Abstract
Increasing knowledge of the deleterious health and economic impacts of aflatoxin in crop commodities has stimulated global interest in aflatoxin mitigation. Current evidence of the incidence of Aspergillus flavus isolates belonging to vegetative compatibility groups (VCGs) lacking the ability to produce aflatoxins (i.e., atoxigenic) in Ghana may lead to the development of an aflatoxin biocontrol strategy to mitigate crop aflatoxin content. In this study, 12 genetically diverse atoxigenic African A. flavus VCGs (AAVs) were identified from fungal communities associated with maize and groundnut grown in Ghana. Representative isolates of the 12 AAVs were assessed for their ability to inhibit aflatoxin contamination by an aflatoxin-producing isolate in laboratory assays. Then, the 12 isolates were evaluated for their potential as biocontrol agents for aflatoxin mitigation when included in three experimental products (each containing four atoxigenic isolates). The three experimental products were evaluated in 50 maize and 50 groundnut farmers' fields across three agroecological zones (AEZs) in Ghana during the 2014 cropping season. In laboratory assays, the atoxigenic isolates reduced aflatoxin biosynthesis by 87-98% compared to grains inoculated with the aflatoxin-producing isolate alone. In field trials, the applied isolates moved to the crops and had higher (P < 0.05) frequencies than other A. flavus genotypes. In addition, although at lower frequencies, most atoxigenic genotypes were repeatedly found in untreated crops. Aflatoxin levels in treated crops were lower by 70-100% in groundnut and by 50-100% in maize (P < 0.05) than in untreated crops. Results from the current study indicate that combined use of appropriate, well-adapted isolates of atoxigenic AAVs as active ingredients of biocontrol products effectively displace aflatoxin producers and in so doing limit aflatoxin contamination. A member each of eight atoxigenic AAVs with superior competitive potential and wide adaptation across AEZs were selected for further field efficacy trials in Ghana. A major criterion for selection was the atoxigenic isolate's ability to colonize soils and grains after release in crop field soils. Use of isolates belonging to atoxigenic AAVs in biocontrol management strategies has the potential to improve food safety, productivity, and income opportunities for smallholder farmers in Ghana.
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Affiliation(s)
- Daniel Agbetiameh
- International Institute of Tropical Agriculture, Ibadan, Nigeria
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Richard T. Awuah
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | - Md-Sajedul Islam
- Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
| | - Kenneth A. Callicott
- Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
| | - Peter J. Cotty
- Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
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17
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Alshannaq AF, Gibbons JG, Lee MK, Han KH, Hong SB, Yu JH. Controlling aflatoxin contamination and propagation of Aspergillus flavus by a soy-fermenting Aspergillus oryzae strain. Sci Rep 2018; 8:16871. [PMID: 30442975 PMCID: PMC6237848 DOI: 10.1038/s41598-018-35246-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 10/31/2018] [Indexed: 01/09/2023] Open
Abstract
Aflatoxins (AFs) are a group of carcinogenic and immunosuppressive mycotoxins that threaten global food safety. Globally, over 4.5 billion people are exposed to unmonitored levels of AFs. Aspergillus flavus is the major source of AF contamination in agricultural crops. One approach to reduce levels of AFs in agricultural commodities is to apply a non-aflatoxigenic competitor, e.g., Afla-Guard, to crop fields. In this study, we demonstrate that the food fermenting Aspergillus oryzae M2040 strain, isolated from Korean Meju (a brick of dry-fermented soybeans), can inhibit aflatoxin B1 (AFB1) production and proliferation of toxigenic A. flavus in lab culture conditions and peanuts. In peanuts, 1% inoculation level of A. oryzae M2040 could effectively displace the toxigenic A. flavus and inhibit AFB1 production. Moreover, cell-free culture filtrate of A. oryzae M2040 effectively inhibited AFB1 production and A. flavus growth, suggesting A. oryzae M2040 secretes inhibitory compounds. Whole genome-based comparative analyses indicate that the A. oryzae M2040 and Afla-Guard genomes are 37.9 and 36.4 Mbp, respectively, with each genome containing ~100 lineage specific genes. Our study establishes the idea of using A. oryzae and/or its cell-free culture fermentate as a potent biocontrol agent to control A. flavus propagation and AF contamination.
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Affiliation(s)
- Ahmad F Alshannaq
- Department of Food Science, University of Wisconsin-Madison, 1605 Linden Dr, Madison, WI, 53706, USA
- Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI, 53706, USA
| | - John G Gibbons
- Department of Food Science, University of Massachusetts, 240 Chenoweth Laboratory, 102 Holdsworth Way, Amherst, MA, 01003, USA
| | - Mi-Kyung Lee
- Biological resource center, Korea Research Institute of Bioscience and Biotechnology, 181 Ipsin-gil, Jeongeup-si, Jeollabuk-do, 56212, Republic of Korea
| | - Kap-Hoon Han
- Department of Pharmaceutical Engineering, Woosuk University, Wanju, 55338, Republic of Korea
| | - Seung-Beom Hong
- Korean Agricultural Culture Collection, Agricultural Microbiology Division, NAS, RDA, Wanju, Republic of Korea
| | - Jae-Hyuk Yu
- Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI, 53706, USA.
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI, 53706, USA.
- Department of Systems Biotechnology, Konkuk University, Seoul, Republic of Korea.
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18
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Ojiambo PS, Battilani P, Cary JW, Blum BH, Carbone I. Cultural and Genetic Approaches to Manage Aflatoxin Contamination: Recent Insights Provide Opportunities for Improved Control. PHYTOPATHOLOGY 2018; 108:1024-1037. [PMID: 29869954 DOI: 10.1094/phyto-04-18-0134-rvw] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Aspergillus flavus is a morphologically complex species that can produce the group of polyketide derived carcinogenic and mutagenic secondary metabolites, aflatoxins, as well as other secondary metabolites such as cyclopiazonic acid and aflatrem. Aflatoxin causes aflatoxicosis when aflatoxins are ingested through contaminated food and feed. In addition, aflatoxin contamination is a major problem, from both an economic and health aspect, in developing countries, especially Asia and Africa, where cereals and peanuts are important food crops. Earlier measures for control of A. flavus infection and consequent aflatoxin contamination centered on creating unfavorable environments for the pathogen and destroying contaminated products. While development of atoxigenic (nonaflatoxin producing) strains of A. flavus as viable commercial biocontrol agents has marked a unique advance for control of aflatoxin contamination, particularly in Africa, new insights into the biology and sexuality of A. flavus are now providing opportunities to design improved atoxigenic strains for sustainable biological control of aflatoxin. Further, progress in the use of molecular technologies such as incorporation of antifungal genes in the host and host-induced gene silencing, is providing knowledge that could be harnessed to develop germplasm that is resistant to infection by A. flavus and aflatoxin contamination. This review summarizes the substantial progress that has been made to understand the biology of A. flavus and mitigate aflatoxin contamination with emphasis on maize. Concepts developed to date can provide a basis for future research efforts on the sustainable management of aflatoxin contamination.
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Affiliation(s)
- Peter S Ojiambo
- First and fifth authors: Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh 27695; second author: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy; third author: U.S. Department of Agriculture-Agriculture Research Service, SRRC, New Orleans, LA 70124; and fourth author: Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | - Paola Battilani
- First and fifth authors: Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh 27695; second author: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy; third author: U.S. Department of Agriculture-Agriculture Research Service, SRRC, New Orleans, LA 70124; and fourth author: Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | - Jeffrey W Cary
- First and fifth authors: Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh 27695; second author: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy; third author: U.S. Department of Agriculture-Agriculture Research Service, SRRC, New Orleans, LA 70124; and fourth author: Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | - Burt H Blum
- First and fifth authors: Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh 27695; second author: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy; third author: U.S. Department of Agriculture-Agriculture Research Service, SRRC, New Orleans, LA 70124; and fourth author: Department of Plant Pathology, University of Arkansas, Fayetteville 72701
| | - Ignazio Carbone
- First and fifth authors: Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh 27695; second author: Department of Sustainable Crop Production, Università Cattolica del Sacro Cuore, Via Emilia Parmense 84, 29122 Piacenza, Italy; third author: U.S. Department of Agriculture-Agriculture Research Service, SRRC, New Orleans, LA 70124; and fourth author: Department of Plant Pathology, University of Arkansas, Fayetteville 72701
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19
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Yin G, Hua SST, Pennerman KK, Yu J, Bu L, Sayre RT, Bennett JW. Genome sequence and comparative analyses of atoxigenic Aspergillus flavus WRRL 1519. Mycologia 2018; 110:482-493. [PMID: 29969379 DOI: 10.1080/00275514.2018.1468201] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Aflatoxins are toxic secondary metabolites produced by Aspergillus flavus and a few other closely related species of Aspergillus. These highly toxigenic and carcinogenic mycotoxins contaminate global food and feed supplies, posing widespread health risks to humans and domestic animals. Field application of nonaflatoxigenic strains of A. flavus to compete against aflatoxigenic strains has emerged as one of the best management practices for reducing aflatoxins contamination, yielding successful commercial products for corn, cotton seed, and peanuts. In this study, we sequenced the genome and transcriptome of atoxigenic (does not produce aflatoxin or cyclopiazonic acid) A. flavus strain WRRL 1519 isolated from a tree nut orchard to define the genetic characteristics of the strain in relation to aflatoxigenic and other nonaflatoxigenic A. flavus strains. WRRL 1519 strain was similar to other strains in size (38.0 Mb), GC content (47.2%), number of predicted secondary metabolite gene clusters (46), and number of putative proteins (12 121). About 87.4% of the predicted proteome had high shared identity with protein sequences derived from other A. flavus genomes. However, the atoxigenic A. flavus strain WRRL 1519 had deletions, or low shared identity, for many genes in the clusters required for aflatoxins and cyclopiazonic acid (CPA) synthesis. Over half of the aflatoxin synthesis gene cluster was missing, and none of the components of the CPA gene cluster were identified with high sequence similarity. Importantly, the strain appeared to maintain functional sequences of several genes thought to be required for high infectivity. Since the ability to grow on target crop is an important attribute for a successful biocontrol agent, these results indicate that the nonaflatoxigenic A. flavus strain WRRL 1519 would be a good candidate as a biocontrol agent for reducing aflatoxin and CPA accumulation in high-value nut crops.
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Affiliation(s)
- Guohua Yin
- a Department of Plant Biology, Rutgers , The State University of New Jersey , New Brunswick , New Jersey 08901.,b New Mexico Consortium and Pebble Labs , Los Alamos , New Mexico 87544
| | - Sui Sheng T Hua
- c Foodborne Toxin Detection and Prevention Research, Western Regional Research Center, Agricultural Research Service , US Department of Agriculture , Albany , California 94710
| | - Kayla K Pennerman
- a Department of Plant Biology, Rutgers , The State University of New Jersey , New Brunswick , New Jersey 08901
| | - Jiujiang Yu
- d Food Quality Laboratory, Agricultural Research Service , US Department of Agriculture, Beltsville Agricultural Research Center , Beltsville , Maryland 20705
| | - Lijing Bu
- e Center for Evolutionary & Theoretical Immunology, Department of Biology , University of New Mexico , Albuquerque , New Mexico 87131
| | - Richard T Sayre
- b New Mexico Consortium and Pebble Labs , Los Alamos , New Mexico 87544
| | - Joan W Bennett
- a Department of Plant Biology, Rutgers , The State University of New Jersey , New Brunswick , New Jersey 08901
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20
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Camiletti BX, Moral J, Asensio CM, Torrico AK, Lucini EI, Giménez-Pecci MDLP, Michailides TJ. Characterization of Argentinian Endemic Aspergillus flavus Isolates and Their Potential Use as Biocontrol Agents for Mycotoxins in Maize. PHYTOPATHOLOGY 2018; 108:818-828. [PMID: 29384448 DOI: 10.1094/phyto-07-17-0255-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Maize (Zea mays L.) is a highly valuable crop in Argentina, frequently contaminated with the mycotoxins produced by Aspergillus flavus. Biocontrol products formulated with atoxigenic (nontoxic) strains of this fungal species are well known as an effective method to reduce this contamination. In the present study, 83 A. flavus isolates from two maize regions of Argentina were characterized and evaluated for their ability to produce or lack of producing mycotoxins in order to select atoxigenic strains to be used as potential biocontrol agents (BCA). All of the isolates were tested for aflatoxin and cyclopiazonic acid (CPA) production in maize kernels and a liquid culture medium. Genetic diversity of the nonaflatoxigenic isolates was evaluated by analysis of vegetative compatibility groups (VCG) and confirmation of deletions in the aflatoxin biosynthesis cluster. Eight atoxigenic isolates were compared for their ability to reduce aflatoxin and CPA contamination in maize kernels in coinoculation tests. The A. flavus population was composed of 32% aflatoxin and CPA producers and 52% CPA producers, and 16% was determined as atoxigenic. All of the aflatoxin producer isolates also produced CPA. Aflatoxin and CPA production was significantly higher in maize kernels than in liquid medium. The 57 nonaflatoxigenic strains formed six VCG, with AM1 and AM5 being the dominant groups, with a frequency of 58 and 35%, respectively. In coinoculation experiments, all of the atoxigenic strains reduced aflatoxin from 54 to 83% and CPA from 60 to 97%. Members of group AM1 showed a greater aflatoxin reduction than members of AM5 (72 versus 66%) but no differences were detected in CPA production. Here, we described for the first time atoxigenic isolates of A. flavus that show promise to be used as BCA in maize crops in Argentina. This innovating biological control approach should be considered, developed further, and used by the maize industry to preserve the quality properties and food safety of maize kernels in Argentina.
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Affiliation(s)
- Boris X Camiletti
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Juan Moral
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Claudia M Asensio
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Ada Karina Torrico
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Enrique I Lucini
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - María de la Paz Giménez-Pecci
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Themis J Michailides
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
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Characterization and competitive ability of non-aflatoxigenic Aspergillus flavus isolated from the maize agro-ecosystem in Argentina as potential aflatoxin biocontrol agents. Int J Food Microbiol 2018; 277:58-63. [PMID: 29684766 DOI: 10.1016/j.ijfoodmicro.2018.04.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 03/26/2018] [Accepted: 04/13/2018] [Indexed: 12/17/2022]
Abstract
Aspergillus flavus is an opportunistic pathogen and may produce aflatoxins in maize, one of the most important crops in Argentina. A promising strategy to reduce aflatoxin accumulation is the biological control based on competitive exclusion. In order to select potential biocontrol agents among isolates from the maize growing region in Argentina, a total of 512 A. flavus strains were isolated from maize kernels and soil samples. Thirty-six per cent of the isolates from maize kernels did not produce detectable levels of aflatoxins, while 73% of the isolates from soil were characterized as non-aflatoxin producers. Forty percent and 49% of the isolates from maize kernels and soil samples, respectively, were not producers of cyclopiazonic acid (CPA). Sclerotia morphology was evaluated using Czapek Dox media. Eighty-six per cent of the isolates from maize kernels and 85% of the isolates from soil samples were L sclerotia morphotype (average diameter > 400 μm). The remaining isolates did not produce sclerotia. All isolates had MAT 1-1 idiomorph. The competitive ability of 9 non aflatoxigenic strains, 4 CPA(+) and 5 CPA(-), was evaluated in co-inoculations of maize kernels with an aflatoxigenic strain. All evaluated strains significantly (p < 0.05) reduced aflatoxin contamination in maize kernels. The aflatoxin B1 (AFB1) reduction ranged from 6 to 60%. The strain A. flavus ARG5/30 isolated from maize kernels would be a good candidate as a potential biocontrol agent to be used in maize, since it was characterized as neither aflatoxin nor CPA producer, morphotype L, MAT 1-1 idiomorph, and reduced AFB1 content in maize kernels by 59%. This study showed the competitive ability of potential aflatoxin biocontrol agents to be evaluated under field trials in a maize agro-ecosystem in Argentina.
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Agbetiameh D, Ortega-Beltran A, Awuah RT, Atehnkeng J, Cotty PJ, Bandyopadhyay R. Prevalence of Aflatoxin Contamination in Maize and Groundnut in Ghana: Population Structure, Distribution, and Toxigenicity of the Causal Agents. PLANT DISEASE 2018; 102:764-772. [PMID: 30673407 PMCID: PMC7779968 DOI: 10.1094/pdis-05-17-0749-re] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Aflatoxin contamination in maize and groundnut is perennial in Ghana with substantial health and economic burden on the population. The present study examined for the first time the prevalence of aflatoxin contamination in maize and groundnut in major producing regions across three agroecological zones (AEZs) in Ghana. Furthermore, the distribution and aflatoxin-producing potential of Aspergillus species associated with both crops were studied. Out of 509 samples (326 of maize and 183 of groundnut), 35% had detectable levels of aflatoxins. Over 15% of maize and 11% of groundnut samples exceeded the aflatoxin threshold limits set by the Ghana Standards Authority of 15 and 20 ppb, respectively. Mycoflora analyses revealed various species and morphotypes within the Aspergillus section Flavi. A total of 5,083 isolates were recovered from both crops. The L morphotype of Aspergillus flavus dominated communities with 93.3% of the population, followed by Aspergillus spp. with S morphotype (6%), A. tamarii (0.4%), and A. parasiticus (0.3%). Within the L morphotype, the proportion of toxigenic members was significantly (P < 0.05) higher than that of atoxigenic members across AEZs. Observed and potential aflatoxin concentrations indicate that on-field aflatoxin management strategies need to be implemented throughout Ghana. The recovered atoxigenic L morphotype fungi are genetic resources that can be employed as biocontrol agents to limit aflatoxin contamination of maize and groundnut in Ghana. Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .
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Affiliation(s)
- D Agbetiameh
- International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria, and Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | | | - R T Awuah
- Department of Crop and Soil Sciences, KNUST, Kumasi, Ghana
| | - J Atehnkeng
- IITA, Chitedze Research Station, P.O. Box 30258, Lilongwe 3, Malawi
| | - P J Cotty
- United States Department of Agriculture, Agricultural Research Service, School of Plant Sciences, University of Arizona, Tucson, AZ 85721
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Ortega-Beltran A, Cotty PJ. Frequent Shifts in Aspergillus flavus Populations Associated with Maize Production in Sonora, Mexico. PHYTOPATHOLOGY 2018; 108:412-420. [PMID: 29027887 DOI: 10.1094/phyto-08-17-0281-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Aspergillus flavus frequently contaminates maize, a critical staple for billions of people, with aflatoxins. Diversity among A. flavus L morphotype populations associated with maize in Sonora, Mexico was assessed and, in total, 869 isolates from 83 fields were placed into 136 vegetative compatibility groups (VCGs) using nitrate-nonutilizing mutants. VCG diversity indices did not differ in four agroecosystems (AES) but diversity significantly differed among years. Frequencies of certain VCGs changed manyfold over single years in both multiple fields and multiple AES. Certain VCGs were highly frequent (>1%) in 2006 but frequencies declined repeatedly in each of the two subsequent years. Other VCGs that had low frequencies in 2006 increased in 2007 and subsequently declined. None of the VCGs were consistently associated with any AES. Fourteen VCGs were considered dominant in at least a single year. However, frequencies often varied significantly among years. Only 9% of VCGs were detected all 3 years whereas 66% were detected in only 1 year. Results suggest that the most realistic measurements of both genetic diversity and the frequency of A. flavus VCGs are obtained by sampling multiple locations in multiple years. Single-season sampling in many locations should not be substituted for sampling over multiple years.
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Affiliation(s)
- A Ortega-Beltran
- First and second authors: School of Plant Sciences, and second author: United States Department of Agriculture-Agricultural Research Service, School of Plant Sciences, The University of Arizona, Tucson
| | - P J Cotty
- First and second authors: School of Plant Sciences, and second author: United States Department of Agriculture-Agricultural Research Service, School of Plant Sciences, The University of Arizona, Tucson
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Mamo FT, Shang B, Selvaraj JN, Wang Y, Liu Y. Isolation and characterization of Aspergillus flavus strains in China. J Microbiol 2018; 56:119-127. [PMID: 29392555 DOI: 10.1007/s12275-018-7144-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 11/25/2022]
Abstract
Important staple foods (peanuts, maize and rice) are susceptible to contamination by aflatoxin (AF)-producing fungi such as Aspergillus flavus. The objective of this study was to explore non-aflatoxin-producing (atoxigenic) A. flavus strains as biocontrol agents for the control of AFs. In the current study, a total of 724 A. flavus strains were isolated from different regions of China. Polyphasic approaches were utilized for species identification. Non-aflatoxin and non-cyclopiazonic acid (CPA)-producing strains were further screened for aflatoxin B1 (AFB1) biosynthesis pathway gene clusters using a PCR assay. Strains lacking an amplicon for the regulatory gene aflR were then analyzed for the presence of the other 28 biosynthetic genes. Only 229 (32%) of the A. flavus strains were found to be atoxigenic. Smaller (S) sclerotial phenotypes were dominant (51%) compared to large (L, 34%) and non-sclerotial (NS, 15%) phenotypes. Among the atoxigenic strains, 24 strains were PCR-negative for the fas-1 and aflJ genes. Sixteen (67%) atoxigenic A. flavus strains were PCRnegative for 10 or more of the biosynthetic genes. Altogether, 18 new PCR product patterns were observed, indicating great diversity in the AFB1 biosynthesis pathway. The current study demonstrates that many atoxigenic A. flavus strains can be isolated from different regions of China. In the future laboratory as well as field based studies are recommended to test these atoxigenic strains as biocontrol agents for aflatoxin contamination.
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Affiliation(s)
- Firew Tafesse Mamo
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China
| | - Bo Shang
- Academy of State Administration of Grain, Beijing, 100037, P. R. China
| | | | - Yan Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China
| | - Yang Liu
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China.
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Mauro A, Garcia-Cela E, Pietri A, Cotty PJ, Battilani P. Biological Control Products for Aflatoxin Prevention in Italy: Commercial Field Evaluation of Atoxigenic Aspergillus flavus Active Ingredients. Toxins (Basel) 2018; 10:E30. [PMID: 29304008 PMCID: PMC5793117 DOI: 10.3390/toxins10010030] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 12/23/2017] [Accepted: 01/02/2018] [Indexed: 11/16/2022] Open
Abstract
Since 2003, non-compliant aflatoxin concentrations have been detected in maize produced in Italy. The most successful worldwide experiments in aflatoxin prevention resulted from distribution of atoxigenic strains of Aspergillusflavus to displace aflatoxin-producers during crop development. The displacement results in lower aflatoxin concentrations in harvested grain. The current study evaluated in field performances of two atoxigenic strains of A. flavus endemic to Italy in artificially inoculated maize ears and in naturally contaminated maize. Co-inoculation of atoxigenic strains with aflatoxin producers resulted in highly significant reductions in aflatoxin concentrations (>90%) in both years only with atoxigenic strain A2085. The average percent reduction in aflatoxin B₁ concentration in naturally contaminated maize fields was 92.3%, without significant differences in fumonisins between treated and control maize. The vegetative compatibility group of A2085 was the most frequently recovered A. flavus in both treated and control plots (average 61.9% and 53.5% of the A. flavus, respectively). A2085 was therefore selected as an active ingredient for biocontrol products and deposited under provisions of the Budapest Treaty in the Belgian Co-Ordinated Collections of Micro-Organisms (BCCM/MUCL) collection (accession MUCL54911). Further work on development of A2085 as a tool for preventing aflatoxin contamination in maize produced in Italy is ongoing with the commercial product named AF-X1™.
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Affiliation(s)
- Antonio Mauro
- International Institute of Tropical Agriculture, P.O. Box 34441 Dar es Salaam, Tanzania.
| | - Esther Garcia-Cela
- Applied Mycology Group, Environment and AgriFood Theme, Cranfield University, Cranfield, Bedford MK43 0AL, UK.
| | - Amedeo Pietri
- Institute of Food Science and Nutrition, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy.
| | - Peter J Cotty
- United States Department of Agriculture, Agricultural Research Service, School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA.
| | - Paola Battilani
- Department Sustainable Crop Production, Università Cattolica del Sacro Cuore, 29100 Piacenza, Italy.
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Udomkun P, Wiredu AN, Nagle M, Müller J, Vanlauwe B, Bandyopadhyay R. Innovative technologies to manage aflatoxins in foods and feeds and the profitability of application - A review. Food Control 2017; 76:127-138. [PMID: 28701823 PMCID: PMC5484778 DOI: 10.1016/j.foodcont.2017.01.008] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 12/21/2016] [Accepted: 01/14/2017] [Indexed: 12/29/2022]
Abstract
Aflatoxins are mainly produced by certain strains of Aspergillus flavus, which are found in diverse agricultural crops. In many lower-income countries, aflatoxins pose serious public health issues since the occurrence of these toxins can be considerably common and even extreme. Aflatoxins can negatively affect health of livestock and poultry due to contaminated feeds. Additionally, they significantly limit the development of international trade as a result of strict regulation in high-value markets. Due to their high stability, aflatoxins are not only a problem during cropping, but also during storage, transport, processing, and handling steps. Consequently, innovative evidence-based technologies are urgently required to minimize aflatoxin exposure. Thus far, biological control has been developed as the most innovative potential technology of controlling aflatoxin contamination in crops, which uses competitive exclusion of toxigenic strains by non-toxigenic ones. This technology is commercially applied in groundnuts maize, cottonseed, and pistachios during pre-harvest stages. Some other effective technologies such as irradiation, ozone fumigation, chemical and biological control agents, and improved packaging materials can also minimize post-harvest aflatoxins contamination in agricultural products. However, integrated adoption of these pre- and post-harvest technologies is still required for sustainable solutions to reduce aflatoxins contamination, which enhances food security, alleviates malnutrition, and strengthens economic sustainability.
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Affiliation(s)
- Patchimaporn Udomkun
- International Institute of Tropical Agriculture (IITA), Bukavu, The Democratic Republic of Congo
| | | | - Marcus Nagle
- Universität Hohenheim, Institute of Agricultural Engineering, Tropics and Subtropics Group, Stuttgart, Germany
| | - Joachim Müller
- Universität Hohenheim, Institute of Agricultural Engineering, Tropics and Subtropics Group, Stuttgart, Germany
| | - Bernard Vanlauwe
- International Institute of Tropical Agriculture (IITA), Nairobi, Kenya
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Hassan SM, Sultana B, Atta A, Qureshi N, Iqbal M, Abbas M. Aflatoxin, proximate composition and mineral profile of stored broiler feed treated with medicinal plant leaves. J Mycol Med 2017; 27:325-333. [PMID: 28483450 DOI: 10.1016/j.mycmed.2017.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 01/30/2017] [Accepted: 03/02/2017] [Indexed: 11/26/2022]
Abstract
OBJECTIVES In the present investigation, the Morus alba (M. alba), Vitis vinifera (V. vinifera), Ficus religiosa (F. religiosa) and Citrus paradisi (C. paradisi) leaves anti-aflatoxigenic activities were evaluated in Aspergillus flavus (A. flavus) inoculated feed. METHODS The broiler feed inoculated with A. flavus was treated with selected medicinal plant leaf powder (5%, 10% and 15% w/w) and stored for the period of six months at 28°C and 16% moisture. The aflatoxins (AFTs) were estimated at the end of each month by Reversed Phase High Performance Liquid Chromatography (RP-HPLC) method along with proximate composition and mineral contents. RESULTS Plant leaves controlled AFTs efficiently without affecting the feed proximate composition and mineral contents. The M. alba leaves completely inhibition (100%) the AFTs (B1 and B2) in feed at very low concentration (5%). Other plants also showed significant (P<0.05) inhibition of AFTs production without affecting the feed quality over the storage period of six months. CONCLUSION Based on promising efficiency of selected medicinal plant leaves, A. flavus produced AFTs could possibly be controlled in stored poultry feed.
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Affiliation(s)
- S M Hassan
- Department of Chemistry, Lahore Garrison University, Lahore, Pakistan
| | - B Sultana
- Department of Chemistry, University of Agriculture, Faisalabad 38040, Pakistan.
| | - A Atta
- Department of Biochemistry, Bahauddin Zakariya University, Multan 60800, Pakistan
| | - N Qureshi
- Department of Chemistry, Karakoram International University, Gilgit 15100 Pakistan
| | - M Iqbal
- Department of Chemistry, The University of Lahore, Lahore, Pakistan.
| | - M Abbas
- Institute of Molecular Biology and Biotechnology, The University of Lahore, 54000 Lahore, Pakistan
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28
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Hassan SM, Sultana B, Iqbal M, Naz S, Abbas M. Anti-aflatoxigenic activity of Punica granatum and Ziziphus jujuba leaves against Aspergillus parasiticus inoculated poultry feed: Effect of storage conditions. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.02.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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29
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Hulikunte Mallikarjunaiah N, Jayapala N, Puttaswamy H, Siddapura Ramachandrappa N. Characterization of non-aflatoxigenic strains of Aspergillus flavus as potential biocontrol agent for the management of aflatoxin contamination in groundnut. Microb Pathog 2017; 102:21-28. [DOI: 10.1016/j.micpath.2016.11.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 11/13/2016] [Accepted: 11/14/2016] [Indexed: 11/25/2022]
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Alaniz Zanon MS, Barros GG, Chulze SN. Non-aflatoxigenic Aspergillus flavus as potential biocontrol agents to reduce aflatoxin contamination in peanuts harvested in Northern Argentina. Int J Food Microbiol 2016; 231:63-8. [PMID: 27220011 DOI: 10.1016/j.ijfoodmicro.2016.05.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 04/22/2016] [Accepted: 05/12/2016] [Indexed: 11/28/2022]
Abstract
Biological control is one of the most promising strategies for preventing aflatoxin contamination in peanuts at field stage. A population of 46 native Aspergillus flavus nonaflatoxin producers were analysed based on phenotypic, physiological and genetic characteristics. Thirty-three isolates were characterized as L strain morphotype, 3 isolates as S strain morphotype, and 10 isolates did not produce sclerotia. Only 11 of 46 non-aflatoxigenic isolates did not produce cyclopiazonic acid. The vegetative compatibility group (VCG) diversity index for the population was 0.37. For field trials we selected the non-aflatoxigenic A. flavus AR27, AR100G and AFCHG2 strains. The efficacy of single and mixed inocula as potential biocontrol agents in Northern Argentina was evaluated through a 2-year study (2014-2015). During the 2014 peanut growing season, most of the treatments reduced the incidence of aflatoxigenic strains in both soil and peanut kernel samples, and no aflatoxin was detected in kernels. During the 2015 growing season, there was a reduction of aflatoxigenic strains in kernel samples from the plots treated with the potential biocontrol agents. Reductions of aflatoxin contamination between 78.36% and 89.55% were observed in treated plots in comparison with the un-inoculated control plots. This study provides the first data on aflatoxin biocontrol based on competitive exclusion in the peanut growing region of Northern Argentina, and proposes bioproducts with potential use as biocontrol agents.
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Affiliation(s)
- María Silvina Alaniz Zanon
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Germán Gustavo Barros
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Sofía Noemí Chulze
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36 Km 601, Río Cuarto, Córdoba, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina.
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Prathivadi Bayankaram P, Sellamuthu PS. Antifungal and anti-aflatoxigenic effect of probiotics againstAspergillus flavusandAspergillus parasiticus. TOXIN REV 2016. [DOI: 10.1080/15569543.2016.1178147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Toxigenic potentiality of Aspergillus flavus and Aspergillus parasiticus strains isolated from black pepper assessed by an LC-MS/MS based multi-mycotoxin method. Food Microbiol 2015; 52:185-96. [DOI: 10.1016/j.fm.2015.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 07/11/2015] [Accepted: 07/22/2015] [Indexed: 01/20/2023]
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Singh D, Radhakrishnan T, Kumar V, Bagwan NB, Basu MS, Dobaria JR, Mishra GP, Chanda SV. Molecular characterisation of Aspergillus flavus isolates from peanut fields in India using AFLP. Braz J Microbiol 2015; 46:673-82. [PMID: 26413047 PMCID: PMC4568877 DOI: 10.1590/s1517-838246320131115] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 11/12/2014] [Indexed: 11/22/2022] Open
Abstract
Aflatoxin contamination of peanut, due to infection by Aspergillus flavus, is a major problem of rain-fed agriculture in India. In the present study, molecular characterisation of 187 Aspergillus flavus isolates, which were sampled from the peanut fields of Gujarat state in India, was performed using AFLP markers. On a pooled cluster analysis, the markers could successfully discriminate among the 'A', 'B' and 'G' group A. flavus isolates. PCoA analysis also showed equivalent results to the cluster analysis. Most of the isolates from one district could be clustered together, which indicated genetic similarity among the isolates. Further, a lot of genetic variability was observed within a district and within a group. The results of AMOVA test revealed that the variance within a population (84%) was more than that between two populations (16%). The isolates, when tested by indirect competitive ELISA, showed about 68.5% of them to be atoxigenic. Composite analysis between the aflatoxin production and AFLP data was found to be ineffective in separating the isolate types by aflatoxigenicity. Certain unique fragments, with respect to individual isolates, were also identified that may be used for development of SCAR marker to aid in rapid and precise identification of isolates.
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Affiliation(s)
| | | | - Vinod Kumar
- Directorate of Groundnut Research, Gujarat, India
| | - N B Bagwan
- Directorate of Groundnut Research, Gujarat, India
| | - M S Basu
- Directorate of Groundnut Research, Gujarat, India
| | - J R Dobaria
- Directorate of Groundnut Research, Gujarat, India
| | | | - S V Chanda
- Department of Biosciences, Saurashtra University, Gujarat, India
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Ehrlich K, Moore G, Mellon J, Bhatnagar D. Challenges facing the biological control strategy for eliminating aflatoxin contamination. WORLD MYCOTOXIN J 2015. [DOI: 10.3920/wmj2014.1696] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Competition with Aspergillus flavus isolates incapable of aflatoxin production is currently the most widely used biocontrol method for reducing aflatoxin contamination in maize and cottonseed where aflatoxin contamination is a persistent problem for human and animal health. The method involves spreading non-aflatoxigenic A. flavus spores onto the field prior to harvest. How competition works is not fully understood. Current theories suggest that atoxigenic A. flavus either simply displaces aflatoxin-producing isolates or that competition is an active inhibition process that occurs when the fungi occupy the same locus on the plant. In this paper we describe several challenges that the biocontrol strategy should address before this practice is introduced worldwide. These include the need to better understand the diversity of A. flavus populations in the agricultural soil, the effects of climate change on both this diversity and on plant susceptibility, the ability of the introduced biocontrol strain to outcross with existing aflatoxin-producing A. flavus, the adaptation of certain A. flavus isolates for predominant growth on the plant rather than in the soil, the difficulty in timing the application or controlling the stability of the inoculum, the effect of the introduction of the biocontrol strain on the soil microenvironment, the potential damage to the plant from the introduced strain, and the overall need to better understand the entire A. flavus toxin burden, beyond that of aflatoxin, that may result from A. flavus contamination. In addition, the cost/benefit ratio for the biocontrol method should be considered in comparing this method to other methods for reducing food and feed contamination with aflatoxins.
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Affiliation(s)
- K.C. Ehrlich
- Southern Regional Research Center, USDA-ARS, 1100 RE Lee Blvd, New Orleans, LA 70124, USA
| | - G.G. Moore
- Southern Regional Research Center, USDA-ARS, 1100 RE Lee Blvd, New Orleans, LA 70124, USA
| | - J.E. Mellon
- Southern Regional Research Center, USDA-ARS, 1100 RE Lee Blvd, New Orleans, LA 70124, USA
| | - D. Bhatnagar
- Southern Regional Research Center, USDA-ARS, 1100 RE Lee Blvd, New Orleans, LA 70124, USA
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Chulze S, Palazzini J, Torres AM, Barros G, Ponsone M, Geisen R, Schmidt-Heydt M, Köhl J. Biological control as a strategy to reduce the impact of mycotoxins in peanuts, grapes and cereals in Argentina. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2014; 32:471-9. [DOI: 10.1080/19440049.2014.984245] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Ma H, Zhang N, Sun L, Qi D. Effects of different substrates and oils on aflatoxin B1 production by Aspergillus parasiticus. Eur Food Res Technol 2014. [DOI: 10.1007/s00217-014-2364-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Perrone G, Gallo A, Logrieco AF. Biodiversity of Aspergillus section Flavi in Europe in relation to the management of aflatoxin risk. Front Microbiol 2014; 5:377. [PMID: 25101075 PMCID: PMC4104701 DOI: 10.3389/fmicb.2014.00377] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/04/2014] [Indexed: 11/13/2022] Open
Abstract
Aflatoxins and the producing fungi Aspergillus section Flavi are widely known as the most serious and dangerous mycotoxin issue in agricultural products. In Europe, before the outbreak of aflatoxins on maize (2003-2004) due to new climatic conditions, their contamination was confined to imported foods. Little information is available on molecular biodiversity and population structure of Aspergillus section Flavi in Europe. Preliminary reports evidenced the massive presence of Aspergillus flavus L -morphotype as the predominant species in maize field, no evidence of the highly toxigenic S-morphotype and of other aflatoxigenic species are reported. The risk of a shift in traditional occurrence areas for aflatoxins is expected in the world and in particular in South East of Europe due to the increasing average temperatures. Biological control of aflatoxin risk in the field by atoxigenic strains of A. flavus starts to be widely used in Africa and USA. Studies are necessary on the variation of aflatoxin production in populations of A. flavus to characterize stable atoxigenic A. flavus strains. The aim of present article is to give an overview on biodiversity and genetic variation of Aspergillus section Flavi in Europe in relation to the management of aflatoxins risk in the field.
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Affiliation(s)
- Giancarlo Perrone
- Institute of Sciences of Food Production, National Research Council Bari, Italy
| | - Antonia Gallo
- Unit of Lecce, Institute of Sciences of Food Production, National Research Council Lecce, Italy
| | - Antonio F Logrieco
- Institute of Sciences of Food Production, National Research Council Bari, Italy
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Ehrlich KC. Non-aflatoxigenic Aspergillus flavus to prevent aflatoxin contamination in crops: advantages and limitations. Front Microbiol 2014; 5:50. [PMID: 24575088 PMCID: PMC3918586 DOI: 10.3389/fmicb.2014.00050] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 01/23/2014] [Indexed: 12/25/2022] Open
Abstract
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.
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Affiliation(s)
- Kenneth C. Ehrlich
- Southern Regional Research Center, United States Department of Agriculture – Agricultural Research ServiceNew Orleans, LA, USA
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