1
|
Zaman S, Khan N, Zahoor M, Ullah R, Bari A, Sohail. Phytochemical-mediated regulation of aflatoxigenic fungi contamination in a shifting climate and environment. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:272. [PMID: 38958785 DOI: 10.1007/s10653-024-02045-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 05/21/2024] [Indexed: 07/04/2024]
Abstract
Mycotoxin contamination poses a significant problem in developing countries, particularly in northern Pakistan's fluctuating climate. This study aimed to assess aflatoxin contamination in medicinal and condiment plants in Upper Dir (dry-temperate) and Upper Swat (moist-temperate) districts. Plant samples were collected and screened for mycotoxins (Aflatoxin-B1 and Aflatoxin-B-2). Results showed high levels of AFB-1 (11,505.42 ± 188.82) as compared to AFB-2 (846 ± 241.56). The maximum contamination of AFB-1 in Coriandrum sativum (1154.5 ± 13.43 ng to 3328 ± 9.9 ng) followed by F. vulgare (883 ± 9.89 ng to 2483 ± 8.4 ng), T. ammi (815 ± 11.31 ng to 2316 ± 7.1 ng), and C. longa (935.5 ± 2.12 ng to 2009 ± 4.2 ng) while the minimum was reported in C. cyminum (671 ± 9.91 ng to 1995 ± 5.7 ng). Antifungal tests indicated potential resistance in certain plant species (C. cyminum) while A. flavus as the most toxins contributing species due to high resistance below 80% (54.2 ± 0.55 to 79.5 ± 2.02). HPLC analysis revealed hydroxyl benzoic acid (5136 amu) as the dominant average phytochemical followed by phloroglucinol (4144.31 amu) with individual contribution of 8542.08 amu and 12,181.5 amu from C. cyaminum. The comparison of average phytochemicals revealed the maximum concentration in C. cyminum (2885.95) followed by C. longa (1892.73). The findings revealed a statistically significant and robust negative correlation (y = - 2.7239 × + 5141.9; r = - 0.8136; p < 0.05) between average mycotoxins and phytochemical concentrations. Temperature positively correlated with aflatoxin levels (p < 0.01), while humidity had a weaker correlation. Elevation showed a negative correlation (p < 0.05), while geographical factors (latitude and longitude) had mixed correlations (p < 0.05). Specific regions exhibited increasing aflatoxin trends due to climatic and geographic factors.
Collapse
Affiliation(s)
- Shah Zaman
- Department of Botany, University of Malakand, Chakdara, KPK, Pakistan.
| | - Nasrullah Khan
- Department of Botany, University of Malakand, Chakdara, KPK, Pakistan
| | - Muhammad Zahoor
- Department of Biochemistry, University of Malakand, Chakdara, KPK, Pakistan
| | - Riaz Ullah
- Departement of Pharmacognosy, College of Pharmacy King Saud University, Riyadh, Saudi Arabia
| | - Ahmed Bari
- Departement of Pharmaceutical Chemistry, College of Pharmacy King Saud University, Riyadh, Saudi Arabia
| | - Sohail
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, 225009, Jiangsu, China
| |
Collapse
|
2
|
Abbas A, Prajapati RK, Aalto-Setälä E, Baykov AA, Malinen AM. Aflatoxin biosynthesis regulators AflR and AflS: DNA binding affinity, stoichiometry, and kinetics. Biochem J 2024; 481:805-821. [PMID: 38829003 DOI: 10.1042/bcj20240084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/29/2024] [Accepted: 06/03/2024] [Indexed: 06/05/2024]
Abstract
Aflatoxins (AFs), potent foodborne carcinogens produced by Aspergillus fungi, pose significant health risks worldwide and present challenges to food safety and productivity in the food chain. Novel strategies for disrupting AF production, cultivating resilient crops, and detecting contaminated food are urgently needed. Understanding the regulatory mechanisms of AF production is pivotal for targeted interventions to mitigate toxin accumulation in food and feed. The gene cluster responsible for AF biosynthesis encodes biosynthetic enzymes and pathway-specific regulators, notably AflR and AflS. While AflR, a DNA-binding protein, activates gene transcription within the cluster, AflS enhances AF production through mechanisms that are not fully understood. In this study, we developed protocols to purify recombinant AflR and AflS proteins and utilized multiple assays to characterize their interactions with DNA. Our biophysical analysis indicated that AflR and AflS form a complex. AflS exhibited no DNA-binding capability on its own but unexpectedly reduced the DNA-binding affinity of AflR. Additionally, we found that AflR achieves its binding specificity through a mechanism in which either two copies of AflR or its complex with AflS bind to target sites on DNA in a highly cooperative manner. The estimated values of the interaction parameters of AflR, AflS and DNA target sites constitute a fundamental framework against which the function and mechanisms of other AF biosynthesis regulators can be compared.
Collapse
Affiliation(s)
- Asmaa Abbas
- Department of Life Technologies, University of Turku, Turku, Finland
| | | | - Emil Aalto-Setälä
- Department of Life Technologies, University of Turku, Turku, Finland
| | - Alexander A Baykov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Anssi M Malinen
- Department of Life Technologies, University of Turku, Turku, Finland
| |
Collapse
|
3
|
Liang L, Wang X, Wei S, Lei Y, Zhang S, Zhai H, Hu Y, Lv Y. m 6A methyltransferase AflIme4 orchestrates mycelial growth, development and aflatoxin B 1 biosynthesis in Aspergillus flavus. Microbiol Res 2024; 283:127710. [PMID: 38593581 DOI: 10.1016/j.micres.2024.127710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/20/2024] [Accepted: 03/30/2024] [Indexed: 04/11/2024]
Abstract
Aflatoxin B1 (AFB1), a highly toxic secondary metabolite produced by Aspergillus flavus, poses a severe threat to agricultural production, food safety and human health. The methylation of mRNA m6A has been identified as a regulator of both the growth and AFB1 production of A. flavus. However, its intracellular occurrence and function needs to be elucidated. Here, we identified and characterized a m6A methyltransferase, AflIme4, in A. flavus. The enzyme was localized in the cytoplasm, and knockout of AflIme4 significantly reduced the methylation modification level of mRNA. Compared with the control strains, ΔAflIme4 exhibited diminished growth, conidial formation, mycelial hydrophobicity, sclerotium yield, pathogenicity and increased sensitivity to CR, SDS, NaCl and H2O2. Notably, AFB1 production was markedly inhibited in the A. flavus ΔAflIme4 strain. RNA-Seq coupled with RT-qPCR validation showed that the transcriptional levels of genes involved in the AFB1 biosynthesis pathway including aflA, aflG, aflH, aflK, aflL, aflO, aflS, aflV and aflY were significantly upregulated. Methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) analysis demonstrated a significant increase in m6A methylation modification levels of these pathway-specific genes, concomitant with a decrease in mRNA stability. These results suggest that AflIme4 attenuates the mRNA stability of genes in AFB1 biosynthesis by enhancing their mRNA m6A methylation modification, leading to impaired AFB1 biosynthesis. Our study identifies a novel m6A methyltransferase AflIme4 and highlights it as a potential target to control A. flavus growth, development and aflatoxin pollution.
Collapse
Affiliation(s)
- Liuke Liang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Xiaoyan Wang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Shan Wei
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yang Lei
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Shuaibing Zhang
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Huanchen Zhai
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yuansen Hu
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China
| | - Yangyong Lv
- College of biological engineering, Henan University of Technology, Zhengzhou 450001, China.
| |
Collapse
|
4
|
Li W, Chen Z, Li X, Li X, Hui Y, Chen W. The Biosynthesis, Structure Diversity and Bioactivity of Sterigmatocystins and Aflatoxins: A Review. J Fungi (Basel) 2024; 10:396. [PMID: 38921382 PMCID: PMC11204465 DOI: 10.3390/jof10060396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/21/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
Sterigmatocystins and aflatoxins are a group of mycotoxins mainly isolated from fungi of the genera Aspergillus. Since the discovery of sterigmatocystins in 1954 and aflatoxins in 1961, many scholars have conducted a series of studies on their structural identification, synthesis and biological activities. Studies have shown that sterigmatocystins and aflatoxins have a wide range of biological activities such as antitumour, antibacterial, anti-inflammatory, antiplasmodial, etc. The sterigmatocystins and aflatoxins had been shown to be hepatotoxic and nephrotoxic in animals. This review attempts to give a comprehensive summary of progress on the chemical structural features, synthesis, and bioactivity of sterigmatocystins and aflatoxins reported from 1954 to April 2024. A total of 72 sterigmatocystins and 20 aflatoxins are presented in this review. This paper reviews the chemical diversity and potential activity and toxicity of sterigmatocystins and aflatoxins, enhances the understanding of sterigmatocystins and aflatoxins that adversely affect humans and animals, and provides ideas for their prevention, research and development.
Collapse
Affiliation(s)
- Wenxing Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Zhaoxia Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Xize Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Xinrui Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Yang Hui
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Wenhao Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| |
Collapse
|
5
|
Inotai K, Bata-Vidács I, Tóth Á, Kosztik J, Varga M, Szekeres A, Nagy I, Nagy I, Dobolyi C, Mörtl M, Székács A, Kukolya J. Glass bead system to study mycotoxin production of Aspergillus spp. on corn and rice starches. Appl Microbiol Biotechnol 2024; 108:348. [PMID: 38809353 PMCID: PMC11136776 DOI: 10.1007/s00253-024-13190-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/13/2024] [Accepted: 05/15/2024] [Indexed: 05/30/2024]
Abstract
Mycotoxin production by aflatoxin B1 (AFB1) -producing Aspergillus flavus Zt41 and sterigmatocystin (ST) -hyperproducer Aspergillus creber 2663 mold strains on corn and rice starch, both of high purity and nearly identical amylose-amylopectin composition, as the only source of carbon, was studied. Scanning electron microscopy revealed average starch particle sizes of 4.54 ± 0.635 µm and 10.9 ± 2.78 µm, corresponding to surface area to volume ratios of 127 1/µm for rice starch and 0.49 1/µm for corn starch. Thus, a 2.5-fold difference in particle size correlated to a larger, 259-fold difference in surface area. To allow starch, a water-absorbing powder, to be used as a sole food source for Aspergillus strains, a special glass bead system was applied. AFB1 production of A. flavus Zt41 was determined to be 437.6 ± 128.4 ng/g and 90.0 ± 44.8 ng/g on rice and corn starch, respectively, while corresponding ST production levels by A. creber 2663 were 72.8 ± 10.0 µg/g and 26.8 ± 11.6 µg/g, indicating 3-fivefold higher mycotoxin levels on rice starch than on corn starch as sole carbon and energy sources. KEY POINTS: • A glass bead system ensuring the flow of air when studying powders was developed. • AFB1 and ST production of A. flavus and A. creber on rice and corn starches were studied. • 3-fivefold higher mycotoxin levels on rice starch than on corn starch were detected.
Collapse
Affiliation(s)
- Katalin Inotai
- Agro-Environmental Research Centre, Institute of Environmental Sciences, Hungarian University of Agriculture and Life Sciences, Páter Károly u. 1, 2100, Gödöllő, Hungary
| | - Ildikó Bata-Vidács
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary.
- HUN-REN-EKKE Lendület Environmental Microbiome Research Group, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary.
| | - Ákos Tóth
- Heart and Vascular Center, Semmelweis University, Városmajor u. 68, 1085, Budapest, Hungary
| | - Judit Kosztik
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary
- HUN-REN-EKKE Lendület Environmental Microbiome Research Group, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary
| | - Mónika Varga
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726, Szeged, Hungary
| | - András Szekeres
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, 6726, Szeged, Hungary
| | - István Nagy
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary
| | - István Nagy
- Seqomics Biotechnology Ltd., Vállalkozók útja 7, 6782, Mórahalom, Hungary
- Institute of Biochemistry, Biological Research Centre, HUN-REN, Temesvári krt. 62, 6726, Szeged, Hungary
| | - Csaba Dobolyi
- Department of Environmental Safety, Institute of Aquaculture and Environmental Safety, Hungarian University of Agriculture and Life Sciences, Páter Károly u. 1, 2100, Gödöllő, Hungary
| | - Mária Mörtl
- Agro-Environmental Research Centre, Institute of Environmental Sciences, Hungarian University of Agriculture and Life Sciences, Páter Károly u. 1, 2100, Gödöllő, Hungary
| | - András Székács
- Agro-Environmental Research Centre, Institute of Environmental Sciences, Hungarian University of Agriculture and Life Sciences, Páter Károly u. 1, 2100, Gödöllő, Hungary
| | - József Kukolya
- Food and Wine Research Institute, Eszterházy Károly Catholic University, Leányka u. 6, 3300, Eger, Hungary
| |
Collapse
|
6
|
Yi X, Han J, Xu X, Wang Y, Zhang M, Zhu J, He Y. Taurine-mediated gene transcription and cell membrane permeability reinforced co-production of bioethanol and Monascus azaphilone pigments for a newly isolated Monascus purpureus. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:59. [PMID: 38702823 PMCID: PMC11069175 DOI: 10.1186/s13068-024-02511-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
BACKGROUND Taurine, a semi-essential micronutrient, could be utilized as a sulfur source for some bacteria; however, little is known about its effect on the accumulation of fermentation products. Here, it investigated the effect of taurine on co-production of bioethanol and Monascus azaphilone pigments (MonAzPs) for a fungus. RESULTS A newly isolated fungus of 98.92% identity with Monascus purpureus co-produced 23.43 g/L bioethanol and 66.12, 78.01 and 62.37 U/mL red, yellow and orange MonAzPs for 3 d in synthetic medium (SM). Taurine enhanced bioethanol titer, ethanol productivity and ethanol yield at the maximum by 1.56, 1.58 and 1.60 times than those of the control in corn stover hydrolysates (CSH), and red, yellow and orange MonAzPs were raised by 1.24, 1.26 and 1.29 times, respectively. Taurine was consumed extremely small quantities for M. purpureus and its promotional effect was not universal for the other two biorefinery fermenting strains. Taurine intensified the gene transcription of glycolysis (glucokinase, phosphoglycerate mutase, enolase and alcohol dehydrogenase) and MonAzPs biosynthesis (serine hydrolases, C-11-ketoreductase, FAD-dependent monooxygenase, 4-O-acyltransferase, deacetylase, NAD(P)H-dependent oxidoredutase, FAD-dependent oxidoredutase, enoyl reductase and fatty acid synthase) through de novo RNA-Seq assays. Furthermore, taurine improved cell membrane permeability through changing cell membrane structure by microscopic imaging assays. CONCLUSIONS Taurine reinforced co-production of bioethanol and MonAzPs by increasing gene transcription level and cell membrane permeability for M. purpureus. This work would offer an innovative, efficient and taurine-based co-production system for mass accumulation of the value-added biofuels and biochemicals from lignocellulosic biomass.
Collapse
Affiliation(s)
- Xia Yi
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Institute of Urban and Rural Mining, Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China.
| | - Jianqi Han
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Institute of Urban and Rural Mining, Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Xiaoyan Xu
- School of Pharmacy & School of Biological and Food Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Yilong Wang
- School of Pharmacy & School of Biological and Food Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Meng Zhang
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Institute of Urban and Rural Mining, Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China
| | - Jie Zhu
- National-Local Joint Engineering Research Center for Biomass Refining and High-Quality Utilization, Institute of Urban and Rural Mining, Changzhou Key Laboratory of Biomass Green, Safe & High Value Utilization Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China.
| | - Yucai He
- School of Pharmacy & School of Biological and Food Engineering, Changzhou University, Changzhou, 213164, Jiangsu, China.
| |
Collapse
|
7
|
Gangurde SS, Korani W, Bajaj P, Wang H, Fountain JC, Agarwal G, Pandey MK, Abbas HK, Chang PK, Holbrook CC, Kemerait RC, Varshney RK, Dutta B, Clevenger JP, Guo B. Aspergillus flavus pangenome (AflaPan) uncovers novel aflatoxin and secondary metabolite associated gene clusters. BMC PLANT BIOLOGY 2024; 24:354. [PMID: 38693487 PMCID: PMC11061970 DOI: 10.1186/s12870-024-04950-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/26/2024] [Indexed: 05/03/2024]
Abstract
BACKGROUND Aspergillus flavus is an important agricultural and food safety threat due to its production of carcinogenic aflatoxins. It has high level of genetic diversity that is adapted to various environments. Recently, we reported two reference genomes of A. flavus isolates, AF13 (MAT1-2 and highly aflatoxigenic isolate) and NRRL3357 (MAT1-1 and moderate aflatoxin producer). Where, an insertion of 310 kb in AF13 included an aflatoxin producing gene bZIP transcription factor, named atfC. Observations of significant genomic variants between these isolates of contrasting phenotypes prompted an investigation into variation among other agricultural isolates of A. flavus with the goal of discovering novel genes potentially associated with aflatoxin production regulation. Present study was designed with three main objectives: (1) collection of large number of A. flavus isolates from diverse sources including maize plants and field soils; (2) whole genome sequencing of collected isolates and development of a pangenome; and (3) pangenome-wide association study (Pan-GWAS) to identify novel secondary metabolite cluster genes. RESULTS Pangenome analysis of 346 A. flavus isolates identified a total of 17,855 unique orthologous gene clusters, with mere 41% (7,315) core genes and 59% (10,540) accessory genes indicating accumulation of high genomic diversity during domestication. 5,994 orthologous gene clusters in accessory genome not annotated in either the A. flavus AF13 or NRRL3357 reference genomes. Pan-genome wide association analysis of the genomic variations identified 391 significant associated pan-genes associated with aflatoxin production. Interestingly, most of the significantly associated pan-genes (94%; 369 associations) belonged to accessory genome indicating that genome expansion has resulted in the incorporation of new genes associated with aflatoxin and other secondary metabolites. CONCLUSION In summary, this study provides complete pangenome framework for the species of Aspergillus flavus along with associated genes for pathogen survival and aflatoxin production. The large accessory genome indicated large genome diversity in the species A. flavus, however AflaPan is a closed pangenome represents optimum diversity of species A. flavus. Most importantly, the newly identified aflatoxin producing gene clusters will be a new source for seeking aflatoxin mitigation strategies and needs new attention in research.
Collapse
Affiliation(s)
- Sunil S Gangurde
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA
| | - Walid Korani
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Prasad Bajaj
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana, India
| | - Hui Wang
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Jake C Fountain
- Department of Plant Pathology, University of Georgia, Griffin, GA, 30223, USA
| | - Gaurav Agarwal
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Manish K Pandey
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana, India.
| | - Hamed K Abbas
- Biological Control of Pests Research Unit, USDA-ARS, Stoneville, MS, 38776, USA
| | - Perng-Kuang Chang
- Southern Regional Research Center, USDA-ARS, New Orleans, LA, 70124, USA
| | - C Corley Holbrook
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA
| | - Robert C Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Rajeev K Varshney
- WA State Biotechnology Centre, Centre for Crop and Food innovation, Food Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
| | - Bhabesh Dutta
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Josh P Clevenger
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.
| | - Baozhu Guo
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA.
| |
Collapse
|
8
|
Karahoda B, Pfannenstiel BT, Sarikaya-Bayram Ö, Dong Z, Ho Wong K, Fleming AB, Keller NP, Bayram Ö. The KdmB-EcoA-RpdA-SntB (KERS) chromatin regulatory complex controls development, secondary metabolism and pathogenicity in Aspergillus flavus. Fungal Genet Biol 2023; 169:103836. [PMID: 37666447 PMCID: PMC10841535 DOI: 10.1016/j.fgb.2023.103836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/28/2023] [Accepted: 09/01/2023] [Indexed: 09/06/2023]
Abstract
The filamentous fungus Aspergillus flavus is a plant and human pathogen predominantly found in the soil as spores or sclerotia and is capable of producing various secondary metabolites (SM) such as the carcinogenic mycotoxin aflatoxin. Recently, we have discovered a novel nuclear chromatin binding complex (KERS) that contains the JARID1-type histone demethylase KdmB, a putative cohesion acetyl transferase EcoA, a class I type histone deacetylase RpdA and the PHD ring finger reader protein SntB in the model filamentous fungus Aspergillus nidulans. Here, we show the presence of the KERS complex in A. flavus by immunoprecipitation-coupled mass spectrometry and constructed kdmBΔ and rpdAΔ strains to study their roles in fungal development, SM production and histone post-translational modifications (HPTMs). We found that KdmB and RpdA couple the regulation of SM gene clusters with fungal light-responses and HPTMs. KdmB and RpdA have opposing roles in light-induced asexual conidiation, while both factors are positive regulators of sclerotia development through the nsdC and nsdD pathway. KdmB and RpdA are essential for the productions of aflatoxin (similar to findings for SntB) as well as cyclopiazonic acid, ditryptophenaline and leporin B through controlling the respective SM biosynthetic gene clusters. We further show that both KdmB and RpdA regulate H3K4me3 and H3K9me3 levels, while RpdA also acts on H3K14ac levels in nuclear extracts. Therefore, the chromatin modifiers KdmB and RpdA of the KERS complex are key regulators for fungal development and SM metabolism in A. flavus.
Collapse
Affiliation(s)
- Betim Karahoda
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Brandon T Pfannenstiel
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, USA
| | | | - Zhiqiang Dong
- Faculty of Health Sciences, University of Macau, Macau
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Macau; Institute of Translational Medicine, University of Macau, Macau; Ministry of Education Frontiers Science Center for Precision Oncology, University of Macau, Macau
| | - Alastair B Fleming
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, USA
| | - Özgür Bayram
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland.
| |
Collapse
|
9
|
Jermnak U, Ngernmeesri P, Yurayart C, Poapolathep A, Udomkusonsri P, Poapolathep S, Phaochoosak N. A New Benzaldehyde Derivative Exhibits Antiaflatoxigenic Activity against Aspergillus flavus. J Fungi (Basel) 2023; 9:1103. [PMID: 37998908 PMCID: PMC10672374 DOI: 10.3390/jof9111103] [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: 09/27/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
Aflatoxin B1 (AFB1) is the most potent naturally occurring carcinogen for humans and animals produced by the common fungus Aspergillus flavus (A. flavus). Aflatoxin (AF) contamination in commodities is a global concern related to the safety of food and feed, and it also impacts the agricultural economy. In this study, we investigated the AFB1-inhibiting activity of a new benzaldehyde derivative, 2-[(2-methylpyridin-3-yl)oxy]benzaldehyde (MPOBA), on A. flavus. It was found that MPOBA inhibited the production of AFB1 by A. flavus, with an IC50 value of 0.55 mM. Moreover, the inhibition of conidiation was also observed at the same concentration. The addition of MPOBA resulted in decreased transcript levels of the aflR gene, which encodes a key regulatory protein for the biosynthesis of AF, and also decreased transcript levels of the global regulator genes veA and laeA. These results suggested that MPOBA has an effect on the regulatory mechanism of the development and differentiation of conidia, leading to the inhibition of AFB1 production. In addition, the cytotoxicity study showed that MPOBA had a very low cytotoxic effect on the Madin-Darby canine kidney (MDCK) cell line. Therefore, MPOBA may be a potential compound for developing practically effective agents to control AF contamination.
Collapse
Affiliation(s)
- Usuma Jermnak
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand; (A.P.); (P.U.); (S.P.); (N.P.)
| | - Paiboon Ngernmeesri
- Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand;
| | - Chompoonek Yurayart
- Department of Veterinary Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand;
| | - Amnart Poapolathep
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand; (A.P.); (P.U.); (S.P.); (N.P.)
| | - Pareeya Udomkusonsri
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand; (A.P.); (P.U.); (S.P.); (N.P.)
| | - Saranya Poapolathep
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand; (A.P.); (P.U.); (S.P.); (N.P.)
| | - Napasorn Phaochoosak
- Department of Pharmacology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand; (A.P.); (P.U.); (S.P.); (N.P.)
| |
Collapse
|
10
|
Huang Z, Wu D, Yang S, Fu W, Ma D, Yao Y, Lin H, Yuan J, Yang Y, Zhuang Z. Regulation of Fungal Morphogenesis and Pathogenicity of Aspergillus flavus by Hexokinase AfHxk1 through Its Domain Hexokinase_2. J Fungi (Basel) 2023; 9:1077. [PMID: 37998882 PMCID: PMC10671980 DOI: 10.3390/jof9111077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/28/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
As a filamentous pathogenic fungus with high-yield of aflatoxin B1, Aspergillus flavus is commonly found in various agricultural products. It is crucial to develop effective strategies aimed at the prevention of the contamination of A. flavus and aflatoxin. Hexokinase AfHxk1 is a critical enzyme in fungal glucose metabolism. However, the role of AfHxk1 in A. flavus development, aflatoxin biosynthesis, and virulence has not yet been explored. In this study, afHxk1 gene deletion mutant (ΔafHxk1), complementary strain (Com-afHxk1), and the domain deletion strains (afHxk1ΔD1 and afHxk1ΔD2) were constructed by homologous recombination. Phenotype study and RT-qPCR revealed that AfHxk1 upregulates mycelium growth and spore and sclerotia formation, but downregulates AFB1 biosynthesis through related classical signaling pathways. Invading models and environmental stress analysis revealed that through involvement in carbon source utilization, conidia germination, and the sensitivity response of A. flavus to a series of environmental stresses, AfHxk1 deeply participates in the regulation of pathogenicity of A. flavus to crop kernels and Galleria mellonella larvae. The construction of domain deletion strains, afHxk1ΔD1 and afHxk1ΔD2, further revealed that AfHxk1 regulates the morphogenesis, mycotoxin biosynthesis, and the fungal pathogenicity mainly through its domain, Hexokinase_2. The results of this study revealed the biological role of AfHxk1 in Aspergillus spp., and might provide a novel potential target for the early control of the contamination of A. flavus.
Collapse
Affiliation(s)
- Zongting Huang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dandan Wu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Sile Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Wangzhuo Fu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Dongmei Ma
- College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou 350002, China;
| | - Yanfang Yao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Hong Lin
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Jun Yuan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Yanling Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Proteomic Research Center, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (Z.H.); (D.W.); (S.Y.); (W.F.); (Y.Y.); (H.L.); (J.Y.); (Y.Y.)
| |
Collapse
|
11
|
Taghizadeh SF, Ahmadpourmir H, Hayes AW, Rezaee R, Karimi G. Probabilistic risk assessment of exposure to multiple mycotoxins in consumers of packaged and unpackaged spices in Iran. Toxicon 2023:107222. [PMID: 37442300 DOI: 10.1016/j.toxicon.2023.107222] [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: 05/12/2023] [Revised: 06/21/2023] [Accepted: 07/09/2023] [Indexed: 07/15/2023]
Abstract
The current study assessed the risk posed to Iranian consumers by oral exposure to a mixture of ten mycotoxins in 138 packaged and unpackaged spices collected from the Iran market. Concentrations of mycotoxins in samples were quantified by liquid chromatography, tandem mass spectrometry with triple quadrupole, and ion trap. Probabilistic health risks of oral exposure to these mycotoxins for Iranians were assessed under percent tolerable daily intake (TDI) and cancer risk scenarios. Mean concentrations of mycotoxins in both packaged and unpackaged spice samples showed statistically significant variation among different spice samples. Based on a Monte Carlo simulation model, at the 50th, 80th, and 95th centiles, oral consumption of the analyzed samples poses no carcinogenic risk for exposure to aflatoxin. Moreover, in both packaged and unpackaged samples, while the percent TDIs for ochratoxin A, deoxynivalenol, zearalenone, patulin, fumonisin B1, and fumonisin B2 were below 1.0 at the 50th, 80th, and 95th centiles, the value was above 1.0 for aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 at each of these centiles.
Collapse
Affiliation(s)
- Seyedeh Faezeh Taghizadeh
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamid Ahmadpourmir
- Department of Pharmacognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - A Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA; Michigan State University, East Lansing, MI, USA
| | - Ramin Rezaee
- International UNESCO Center for Health-Related Basic Sciences and Human Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Gholamreza Karimi
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
| |
Collapse
|
12
|
Li Z, Sun Y, Gu L, Wang Y, Xu M, Zhou Y, Hu Y, Ma W. Ar-turmerone suppresses Aspergillus flavus growth and aflatoxin accumulation: Finding a new antifungal agent based on stored maize. Food Res Int 2023; 168:112735. [PMID: 37120196 DOI: 10.1016/j.foodres.2023.112735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 04/03/2023]
Abstract
Aspergillus flavus (A. flavus) is a common saprophytic pathogenic fungus that produces toxic and carcinogenic aflatoxins prone to contaminate food. Here, we optimized the synthesis method of Ar-turmerone, the main active ingredient in turmeric essential oil, improved its yield and reduced the operation requirements. Moreover, 50.0 μg/mL Ar-turmerone 100.0 % inhibited the colonies growth, spore germination, mycelium biomass and aflatoxin accumulation in 7 days. 2,018 differentially expressed genes (DEGs) such as catA, ppoC, erg7, erg6 and aflO related to the A. flavus growth and aflatoxin product were significantly downregulated including 45 DEGs were 100.0 % suppressed. Besides, Ar-turmerone greatly reduced A. flavus in maize, the optimal storage conditions for maize to avoid A. flavus contamination were determined as 0.940 aw, 400.0 μg/mL Ar-turmerone, and 16.0 °C. Satisfactory odor, luster, taste, and mildew in maize observed after three weeks of storage under the optimal conditions. Thus, Ar-turmerone can be used as a potential food antifungal agent against A. flavus growth and aflatoxin accumulation during food storage.
Collapse
Affiliation(s)
- Zheyu Li
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China.
| | - Yanan Sun
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu 610106, People's Republic of China
| | - Linghui Gu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China
| | - Yuchi Wang
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China
| | - Mingqin Xu
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China
| | - Yunhao Zhou
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China
| | - Yichen Hu
- Key Laboratory of Coarse Cereal Processing, Ministry of Agriculture and Rural Affairs, College of Food and Biological Engineering, Chengdu University, Chengdu 610106, People's Republic of China.
| | - Wenbo Ma
- Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, Chengdu University, Chengdu 610052, China.
| |
Collapse
|
13
|
Corbu VM, Gheorghe-Barbu I, Dumbravă AȘ, Vrâncianu CO, Șesan TE. Current Insights in Fungal Importance-A Comprehensive Review. Microorganisms 2023; 11:1384. [PMID: 37374886 DOI: 10.3390/microorganisms11061384] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 05/20/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
Besides plants and animals, the Fungi kingdom describes several species characterized by various forms and applications. They can be found in all habitats and play an essential role in the excellent functioning of the ecosystem, for example, as decomposers of plant material for the cycling of carbon and nutrients or as symbionts of plants. Furthermore, fungi have been used in many sectors for centuries, from producing food, beverages, and medications. Recently, they have gained significant recognition for protecting the environment, agriculture, and several industrial applications. The current article intends to review the beneficial roles of fungi used for a vast range of applications, such as the production of several enzymes and pigments, applications regarding food and pharmaceutical industries, the environment, and research domains, as well as the negative impacts of fungi (secondary metabolites production, etiological agents of diseases in plants, animals, and humans, as well as deteriogenic agents).
Collapse
Affiliation(s)
- Viorica Maria Corbu
- Genetics Department, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania
- Research Institute of the University of Bucharest-ICUB, 91-95 Spl. Independentei, 050095 Bucharest, Romania
| | - Irina Gheorghe-Barbu
- Research Institute of the University of Bucharest-ICUB, 91-95 Spl. Independentei, 050095 Bucharest, Romania
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania
| | - Andreea Ștefania Dumbravă
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania
| | - Corneliu Ovidiu Vrâncianu
- Research Institute of the University of Bucharest-ICUB, 91-95 Spl. Independentei, 050095 Bucharest, Romania
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania
| | - Tatiana Eugenia Șesan
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, 060101 Bucharest, Romania
- Academy of Agricultural Sciences and Forestry, 61 Bd. Mărăşti, District 1, 011464 Bucharest, Romania
| |
Collapse
|
14
|
Prasad K, Yogendra K, Sanivarapu H, Rajasekaran K, Cary JW, Sharma KK, Bhatnagar-Mathur P. Multiplexed Host-Induced Gene Silencing of Aspergillus flavus Genes Confers Aflatoxin Resistance in Groundnut. Toxins (Basel) 2023; 15:toxins15050319. [PMID: 37235354 DOI: 10.3390/toxins15050319] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/18/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023] Open
Abstract
Aflatoxins are immunosuppressive and carcinogenic secondary metabolites, produced by the filamentous ascomycete Aspergillus flavus, that are hazardous to animal and human health. In this study, we show that multiplexed host-induced gene silencing (HIGS) of Aspergillus flavus genes essential for fungal sporulation and aflatoxin production (nsdC, veA, aflR, and aflM) confers enhanced resistance to Aspergillus infection and aflatoxin contamination in groundnut (<20 ppb). Comparative proteomic analysis of contrasting groundnut genotypes (WT and near-isogenic HIGS lines) supported a better understanding of the molecular processes underlying the induced resistance and identified several groundnut metabolites that might play a significant role in resistance to Aspergillus infection and aflatoxin contamination. Fungal differentiation and pathogenicity proteins, including calmodulin, transcriptional activator-HacA, kynurenine 3-monooxygenase 2, VeA, VelC, and several aflatoxin pathway biosynthetic enzymes, were downregulated in Aspergillus infecting the HIGS lines. Additionally, in the resistant HIGS lines, a number of host resistance proteins associated with fatty acid metabolism were strongly induced, including phosphatidylinositol phosphate kinase, lysophosphatidic acyltransferase-5, palmitoyl-monogalactosyldiacylglycerol Δ-7 desaturase, ceramide kinase-related protein, sphingolipid Δ-8 desaturase, and phospholipase-D. Combined, this knowledge can be used for groundnut pre-breeding and breeding programs to provide a safe and secure food supply.
Collapse
Affiliation(s)
- Kalyani Prasad
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India
| | - Kalenahalli Yogendra
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India
| | - Hemalatha Sanivarapu
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India
| | - Kanniah Rajasekaran
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA/ARS), New Orleans, LA 70124, USA
| | - Jeffrey W Cary
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA/ARS), New Orleans, LA 70124, USA
| | - Kiran K Sharma
- Sustainable Agriculture Program, The Energy and Resources Institute (TERI), India Habitat Center, New Delhi 110003, India
| | - Pooja Bhatnagar-Mathur
- International Maize and Wheat Improvement Center (CIMMYT), El Batán, Texcoco 56237, Mexico
| |
Collapse
|
15
|
Wu S, Huang W, Wang F, Zou X, Li X, Liu CM, Zhang W, Yan S. Integrated metabolomics and lipidomics analyses suggest the temperature-dependent lipid desaturation promotes aflatoxin biosynthesis in Aspergillus flavus. Front Microbiol 2023; 14:1137643. [PMID: 37065116 PMCID: PMC10102665 DOI: 10.3389/fmicb.2023.1137643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 03/17/2023] [Indexed: 04/03/2023] Open
Abstract
Temperature is one of the main factors affecting aflatoxin (AF) biosynthesis in Aspergillus flavus. Previous studies showed that AF biosynthesis is elevated in A. flavus at temperatures between 28°C-30°C, while it is inhibited at temperatures above 30°C. However, little is known about the metabolic mechanism underlying temperature-regulated AF biosynthesis. In this study, we integrated metabolomic and lipidomic analyses to investigate the endogenous metabolism of A. flavus across 6 days of mycelia growth at 28°C (optimal AF production) and 37°C (no AF production). Results showed that both metabolite and lipid profiles were significantly altered at different temperatures. In particular, metabolites involved in carbohydrate and amino acid metabolism were up-regulated at 37°C on the second day but down-regulated from days three to six. Moreover, lipidomics and targeted fatty acids analyses of mycelia samples revealed a distinct pattern of lipid species and free fatty acids desaturation. High degrees of polyunsaturation of most lipid species at 28°C were positively correlated with AF production. These results provide new insights into the underlying metabolic changes in A. flavus under temperature stress.
Collapse
Affiliation(s)
- Shaowen Wu
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Wenjie Huang
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Fenghua Wang
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Xinlu Zou
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Xuan Li
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Chun-Ming Liu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Wenyang Zhang
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Shijuan Yan
- Guangdong Key Laboratory for Crop Germplasm Resources Preservation and Utilization, Agro-biological Gene Research Center, Guangdong Academy of Agricultural Sciences, Guangzhou, China
- *Correspondence: Shijuan Yan,
| |
Collapse
|
16
|
Rotimi OA, De Campos OC, Adelani IB, Olawole TD, Rotimi SO. Early-life AFB1 exposure: DNA methylation and hormone alterations. VITAMINS AND HORMONES 2023; 122:237-252. [PMID: 36863796 DOI: 10.1016/bs.vh.2022.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Aflatoxins are secondary metabolites of mold that contaminate food and feedstuff. They are found in various food including grains, nuts, milk and eggs. Aflatoxin B1 (AFB1) is the most poisonous and commonly found of the various types of aflatoxins. Exposures to AFB1 start early in life viz. in utero, during breastfeeding, and during weaning through the waning foods which are mainly grain based. Several studies have shown that early-life exposures to various contaminants may have various biological effects. In this chapter, we reviewed the effects of early-life AFB1 exposures on changes in hormone and DNA methylation. In utero AFB1 exposure results in alterations in steroid and growth hormones. Specifically, the exposure results in a reduction in testosterone levels later in life. The exposure also affects the methylation of various genes that are significant in growth, immune, inflammation, and signaling pathways.
Collapse
|
17
|
Risk assessments for the dietary intake aflatoxins in food: A systematic review (2016–2022). Food Control 2023. [DOI: 10.1016/j.foodcont.2023.109687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
|
18
|
Thakur C, Malhotra AS, Shankar J. Integrated Bioinformatics Analysis to Study Gallic Acid-Mediated Inhibition of Polyketide Synthase A from Aflatoxin Biosynthesis Pathway of Aspergillus flavus. CHEMISTRY AFRICA 2023. [DOI: 10.1007/s42250-023-00589-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
19
|
Loi M, Logrieco AF, Pusztahelyi T, Leiter É, Hornok L, Pócsi I. Advanced mycotoxin control and decontamination techniques in view of an increased aflatoxin risk in Europe due to climate change. Front Microbiol 2023; 13:1085891. [PMID: 36762096 PMCID: PMC9907446 DOI: 10.3389/fmicb.2022.1085891] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Aflatoxins are toxic secondary metabolites produced by Aspergillus spp. found in staple food and feed commodities worldwide. Aflatoxins are carcinogenic, teratogenic, and mutagenic, and pose a serious threat to the health of both humans and animals. The global economy and trade are significantly affected as well. Various models and datasets related to aflatoxins in maize have been developed and used but have not yet been linked. The prevention of crop loss due to aflatoxin contamination is complex and challenging. Hence, the set-up of advanced decontamination is crucial to cope with the challenge of climate change, growing population, unstable political scenarios, and food security problems also in European countries. After harvest, decontamination methods can be applied during transport, storage, or processing, but their application for aflatoxin reduction is still limited. Therefore, this review aims to investigate the effects of environmental factors on aflatoxin production because of climate change and to critically discuss the present-day and novel decontamination techniques to unravel gaps and limitations to propose them as a tool to tackle an increased aflatoxin risk in Europe.
Collapse
Affiliation(s)
- Martina Loi
- Institute of Sciences of Food Production, National Research Council, Bari, Italy,*Correspondence: Martina Loi, ✉
| | - Antonio F. Logrieco
- Institute of Sciences of Food Production, National Research Council, Bari, Italy
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, Institute of Biotechnology, University of Debrecen, Debrecen, Hungary,ELRN-UD Fungal Stress Biology Research Group, University of Debrecen, Debrecen, Hungary
| | - László Hornok
- Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, Institute of Biotechnology, University of Debrecen, Debrecen, Hungary,ELRN-UD Fungal Stress Biology Research Group, University of Debrecen, Debrecen, Hungary
| |
Collapse
|
20
|
Aflatoxins: Source, Detection, Clinical Features and Prevention. Processes (Basel) 2023. [DOI: 10.3390/pr11010204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The most potent mycotoxin, aflatoxins are the secondary metabolite produced by fungi, especially Aspergillus, and have been found to be ubiquitous, contaminating cereals, crops, and even milk and causing major health and economic issues in some countries due to poor storage, substandard management, and lack of awareness. Different aspects of the toxin are reviewed here, including its structural biochemistry, occurrence, factors conducive to its contamination and intoxication and related clinical features, as well as suggested preventive and control strategies and detection methods.
Collapse
|
21
|
Zahija I, Jeršek B, Demšar L, Polak ML, Polak T. Production of Aflatoxin B1 by Aspergillus parasiticus Grown on a Novel Meat-Based Media. Toxins (Basel) 2022; 15:25. [PMID: 36668845 PMCID: PMC9866511 DOI: 10.3390/toxins15010025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/25/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
The aim of the present study was to develop meat-based media with compositions similar to those of dry-fermented meat products and to evaluate their use in studying the growth of Aspergillus parasiticus and the kinetics of aflatoxin B1 (AFB1) production. In our previous experiments, we found that the strain A. parasiticus ŽMJ7 produced a high amount of AFB1. Cooked meat agar (CMA2) was used as a novel complex meat-based medium with four variations: CMA2G (CMA2 supplemented with 1% glucose), CMA2YE (CMA2 supplemented with 0.2% yeast extract), and CMA2GYE (CMA2 supplemented with 1% glucose and 0.2% yeast extract). Media were inoculated with an A. parasiticus spore suspension (105 spores/mL) and incubated at 25 °C for up to 15 days. The A. parasiticus lag phase lasted less than 1 day, irrespective of the growth medium, with the exception of control medium CMA1 (cooked meat agar) as an already known meat-based medium. The highest mean colony growth rate was observed on CMA2 and CMA2G. Reversed-phase UPLC-MS/MS analysis was performed to determine the AFB1 concentration in combination with solid phase extraction (SPE). The highest AFB1 concentration in meat-based media was detected in CMA2GYE after 15 days of incubation (13,502 ± 2367 ng/mL media). The results showed that for studying AFB1 production in dry-fermented meat products, novel suitable media such as CMA2-based media are required. This finding could represent a potential concern with regard to the production of dry-fermented meat products.
Collapse
Affiliation(s)
| | | | | | | | - Tomaž Polak
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, 1000 Ljubljana, Slovenia
| |
Collapse
|
22
|
Inhibition of Aflatoxin Production by Citrinin and Non-Enzymatic Formation of a Novel Citrinin-Kojic Acid Adduct. J Fungi (Basel) 2022; 9:jof9010029. [PMID: 36675850 PMCID: PMC9861921 DOI: 10.3390/jof9010029] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/30/2022] [Accepted: 12/08/2022] [Indexed: 12/28/2022] Open
Abstract
Screening for microorganisms that inhibit aflatoxin production from environments showed that Penicillium citrinum inhibited aflatoxin production by Aspergillus parasiticus. The inhibitory substance in the culture medium of P. citrinum was confirmed to be citrinin (CTN). RT-PCR analyses showed that CTN did not inhibit expressions of aflatoxin biosynthetic genes (aflR, pksL1, and fas-1) of A. parasiticus, whereas feeding experiments using A. parasiticus showed that CTN inhibited the in vivo conversion of dihydrosterigmatocystin to AFB2·AFG2. These results suggest that CTN inhibits a certain post-transcriptional step in aflatoxin biosynthesis. CTN in the culture medium of A. parasiticus was found to be decreased or lost with time, suggesting that a certain metabolite produced by A. parasiticus is the cause of the CTN decrease; we then purified, characterized, and then analyzed the substance. Physico-chemical analyses confirmed that the metabolite causing a decrease in CTN fluorescence was kojic acid (KA) and the resulting product was identified as a novel substance: (1R,3S,4R)-3,4-dihydro-6,8-dihydroxy-1-(3-hydroxy-6-(hydroxymethyl)-4-oxo-4H-pyran-2-yl)-3,4,5-trimethyl-1H-isochromene-7-carboxylic acid, which was named "CTN-KA adduct". Our examination of the metabolites' toxicities revealed that unlike CTN, the CTN-KA adduct did not inhibit aflatoxin production by A. parasiticus. These results indicate that CTN's toxicity was alleviated with KA by converting CTN to the CTN-KA adduct.
Collapse
|
23
|
Wang W, Liang X, Li Y, Wang P, Keller NP. Genetic Regulation of Mycotoxin Biosynthesis. J Fungi (Basel) 2022; 9:jof9010021. [PMID: 36675842 PMCID: PMC9861139 DOI: 10.3390/jof9010021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Mycotoxin contamination in food poses health hazards to humans. Current methods of controlling mycotoxins still have limitations and more effective approaches are needed. During the past decades of years, variable environmental factors have been tested for their influence on mycotoxin production leading to elucidation of a complex regulatory network involved in mycotoxin biosynthesis. These regulators are putative targets for screening molecules that could inhibit mycotoxin synthesis. Here, we summarize the regulatory mechanisms of hierarchical regulators, including pathway-specific regulators, global regulators and epigenetic regulators, on the production of the most critical mycotoxins (aflatoxins, patulin, citrinin, trichothecenes and fumonisins). Future studies on regulation of mycotoxins will provide valuable knowledge for exploring novel methods to inhibit mycotoxin biosynthesis in a more efficient way.
Collapse
Affiliation(s)
- Wenjie Wang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Correspondence: (W.W.); (N.P.K.)
| | - Xinle Liang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Yudong Li
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Pinmei Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: (W.W.); (N.P.K.)
| |
Collapse
|
24
|
Saber H, Chebloune Y, Moussaoui A. Molecular Characterization of Aspergillus flavus Strains Isolated from Animal Feeds. Pol J Microbiol 2022; 71:589-599. [PMID: 36537059 PMCID: PMC9944975 DOI: 10.33073/pjm-2022-048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/21/2022] [Indexed: 12/24/2022] Open
Abstract
Aflatoxin (AF)-producing fungi such as Aspergillus flavus commonly contaminate animal feeds, causing high economic losses. A. flavus is the most prevalent and produces AFB1, a potent mutagen, and carcinogen threatening human and animal health. Aspergillaceae is a large group of closely related fungi sharing number of morphological and genetic similarities that complicate the diagnosis of highly pathogenic strains. We used here morphological and molecular assays to characterize fungal isolates from animal feeds in Southwestern Algeria. These tools helped to identify 20 out of 30 Aspergillus strains, and 15 of them belonged to the Aspergillus section Flavi. Further analyses detected four out of 15 as belonging to Aspergillus flavus-parasiticus group. PCR targeting the AF genes' aflR-aflS(J) intergenic region amplified a single 674 bp amplicon in all four isolates. The amplicons were digested with a BglII endonuclease, and three specific fragments were observed for A. flavus but A. parasitucus lacked two typical fragments. Sequencing data of four amplicons confirmed the presence of the two BglII restriction sites yielding the three fragments, confirming that all four strains were A. flavus. In addition, this analysis illustrated the genetic variability within the A. flavus strains.
Collapse
Affiliation(s)
- Hadjer Saber
- Laboratory of Plant Resources Valorization and Food Safety in Semi-Arid Areas of Southwestern Algeria, Department of Biology, University of Bechar, Bechar, Algeria
| | - Yahia Chebloune
- USC 1450 INRAE/UGA Lentiviral Pathogenesis and Vaccination Laboratory, Department of Biology, University of Grenoble Alpes, Saint-Martin-d’Hères, France, Y. Chebloune, Lentiviral Pathogenesis and Vaccination Laboratory, PAVAL Lab., Department of Biology, University of Grenoble Alpes, Saint-Martin-d’Hères, France;
| | - Abdallah Moussaoui
- Laboratory of Plant Resources Valorization and Food Safety in Semi-Arid Areas of Southwestern Algeria, Department of Biology, University of Bechar, Bechar, Algeria
| |
Collapse
|
25
|
Aflatoxins in Feed: Types, Metabolism, Health Consequences in Swine and Mitigation Strategies. Toxins (Basel) 2022; 14:toxins14120853. [PMID: 36548750 PMCID: PMC9783261 DOI: 10.3390/toxins14120853] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/21/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Feeding farm animals with aflatoxin-contaminated feed can cause various severe toxic effects, leading to increased susceptibility to infectious diseases and increased mortality, weight loss, poor performance and reduced reproductive capability. Following ingestion of contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in animals. Swine metabolism is not effective in detoxifying and excreting aflatoxins, meaning the risk of aflatoxicosis is increased. Thus, it is of great importance to elucidate the metabolism and all metabolic pathways associated with this mycotoxin. The damage induced by AFB1 in cells and tissues consists of inhibition of cell proliferation, carcinogenicity, immunosuppression, mutagenicity, oxidative stress, lipid peroxidation and DNA damage, leading to pathological lesions in the liver, spleen, lymph node, kidney, uterus, heart, and lungs of swine. At present, it is a challenging task and of serious concern to completely remove aflatoxins and their metabolites from feedstuff; thus, the aim of this study was a literature review on the deleterious effects of aflatoxins on swine metabolism, as well as alternatives that contribute to the detoxification or amelioration of aflatoxin-induced effects in farm animal feed.
Collapse
|
26
|
Comprehensive Review of Aflatoxin Contamination, Impact on Health and Food Security, and Management Strategies in Pakistan. Toxins (Basel) 2022; 14:toxins14120845. [PMID: 36548742 PMCID: PMC9781569 DOI: 10.3390/toxins14120845] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/22/2022] [Accepted: 11/26/2022] [Indexed: 12/05/2022] Open
Abstract
Aflatoxins (AFs) are the most important toxic, mutagenic, and carcinogenic fungal toxins that routinely contaminate food and feed. While more than 20 AFs have been identified to date, aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), and M1 (AFM1) are the most common. Over 25 species of Aspergillus have been shown to produce AFs, with Aspergillus flavus, Aspergillus parasiticus, and Aspergillus nomius being the most important and well-known AF-producing fungi. These ubiquitous molds can propagate on agricultural commodities to produce AFs in fields and during harvesting, processing, transportation, and storage. Countries with warmer climates and that produce foods susceptible to AF contamination shoulder a substantial portion of the global AF burden. Pakistan's warm climate promotes the growth of toxigenic fungi, resulting in frequent AF contamination of human foods and animal feeds. The potential for contamination in Pakistan is exacerbated by improper storage conditions and a lack of regulatory limits and enforcement mechanisms. High levels of AFs in common commodities produced in Pakistan are a major food safety problem, posing serious health risks to the population. Furthermore, aflatoxin contamination contributes to economic losses by limiting exports of these commodities. In this review, recent information regarding the fungal producers of AFs, prevalence of AF contamination of foods and feed, current regulations, and AF prevention and removal strategies are summarized, with a major focus on Pakistan.
Collapse
|
27
|
Zhuang Z, Pan X, Zhang M, Liu Y, Huang C, Li Y, Hao L, Wang S. Set2 family regulates mycotoxin metabolism and virulence via H3K36 methylation in pathogenic fungus Aspergillus flavus. Virulence 2022; 13:1358-1378. [PMID: 35943142 PMCID: PMC9364737 DOI: 10.1080/21505594.2022.2101218] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aspergillus flavus infects various crops with aflatoxins, and leads to aspergillosis opportunistically. Though H3K36 methylation plays an important role in fungal toxin metabolism and virulence, no data about the biological function of H3K36 methylation in A. flavus virulence has been reported. Our study showed that the Set2 histone methyltransferase family, AshA and SetB, involves in morphogenesis and mycotoxin anabolism by regulating related transcriptional factors, and they are important for fungal virulence to crops and animals. Western-blotting and double deletion analysis revealed that AshA mainly regulates H3K36me2, whereas SetB is mainly responsible for H3K36me3 in the nucleus. By construction of domain deletion A. flavus strain and point mutation strains by homologous recombination, the study revealed that SET domain is indispensable in mycotoxin anabolism and virulence of A. flavus, and N455 and V457 in it are the key amino acid residues. ChIP analysis inferred that the methyltransferase family controls fungal reproduction and regulates the production of AFB1 by directly regulating the production of the transcriptional factor genes, including wetA, steA, aflR and amylase, through H3K36 trimethylation in their chromatin fragments, based on which this study proposed that, by H3K36 trimethylation, this methyltransferase family controls AFB1 anabolism through transcriptional level and substrate utilization level. This study illuminates the epigenetic mechanism of the Set2 family in regulating fungal virulence and mycotoxin production, and provides new targets for controlling the virulence of the fungus A. flavus.
AUTHOR SUMMARY
The methylation of H3K36 plays an important role in the fungal secondary metabolism and virulence, but no data about the regulatory mechanism of H3K36 methylation in the virulence of A. flavus have been reported. Our study revealed that, in the histone methyltransferase Set2 family, AshA mainly catalyzes H3K36me2, and involves in the methylation of H3K36me1, and SetB mainly catalyzes H3K36me3 and H3K36me1. Through domain deletion and point mutation analysis, this study also revealed that the SET domain was critical for the normal biological function of the Set2 family and that N455 and V457 in the domain were critical for AshA. By ChIP-seq and ChIP-qPCR analysis, H3K36 was found to be trimethylation modified in the promotors and ORF positions of wetA, steA, aflR and the amylase gene (AFLA_084340), and further qRT-PCR results showed that these methylation modifications regulate the expression levels of these genes. According to the results of ChIP-seq analysis, we proposed that, by H3K36 trimethylation, this methyltransferase family controls the metabolism of mycotoxin through transcriptional level and substrate utilization level. All the results from this study showed that Set2 family is essential for fungal secondary metabolism and virulence, which lays a theoretical groundwork in the early prevention and treatment of A. flavus pollution, and also provides an effective strategy to fight against other pathogenic fungi.
Collapse
Affiliation(s)
- Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaohua Pan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Key Laboratory of Propagated Sensation along Meridian, Fujian Academy of Chinese Medical Sciences, Fuzhou, China
| | - Mengjuan Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yaju Liu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chuanzhong Huang
- Immuno-Oncology Laboratory of Fujian Cancer Hospital, Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fujian Medical University Cancer Hospital, Fuzhou, China
| | - Yu Li
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ling Hao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| |
Collapse
|
28
|
Kumar P, Gupta A, Mahato DK, Pandhi S, Pandey AK, Kargwal R, Mishra S, Suhag R, Sharma N, Saurabh V, Paul V, Kumar M, Selvakumar R, Gamlath S, Kamle M, Enshasy HAE, Mokhtar JA, Harakeh S. Aflatoxins in Cereals and Cereal-Based Products: Occurrence, Toxicity, Impact on Human Health, and Their Detoxification and Management Strategies. Toxins (Basel) 2022; 14:toxins14100687. [PMID: 36287956 PMCID: PMC9609140 DOI: 10.3390/toxins14100687] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/08/2022] Open
Abstract
Cereals and cereal-based products are primary sources of nutrition across the world. However, contamination of these foods with aflatoxins (AFs), secondary metabolites produced by several fungal species, has raised serious concerns. AF generation in innate substrates is influenced by several parameters, including the substrate type, fungus species, moisture content, minerals, humidity, temperature, and physical injury to the kernels. Consumption of AF-contaminated cereals and cereal-based products can lead to both acute and chronic health issues related to physical and mental maturity, reproduction, and the nervous system. Therefore, the precise detection methods, detoxification, and management strategies of AFs in cereal and cereal-based products are crucial for food safety as well as consumer health. Hence, this review provides a brief overview of the occurrence, chemical characteristics, biosynthetic processes, health hazards, and detection techniques of AFs, along with a focus on detoxification and management strategies that could be implemented for food safety and security.
Collapse
Affiliation(s)
- Pradeep Kumar
- Department of Botany, University of Lucknow, Lucknow 226007, India
- Applied Microbiology Laboratory, Department of Forestry, North Eastern Regional Institute of Science and Technology, Nirjuli 791109, India
- Correspondence: (P.K.); (D.K.M.)
| | - Akansha Gupta
- Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
- CASS Food Research Centre, School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Dipendra Kumar Mahato
- CASS Food Research Centre, School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia
- Correspondence: (P.K.); (D.K.M.)
| | - Shikha Pandhi
- Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Arun Kumar Pandey
- MMICT&BM(HM), Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala 133207, India
| | - Raveena Kargwal
- Department of Processing and Food Engineering, College of Agricultural Engineering and Technology, Chaudhary Charan Singh Haryana Agricultural University, Hisar 125004, India
| | - Sadhna Mishra
- Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
- Faculty of Agricultural Sciences, GLA University, Mathura 281406, India
| | - Rajat Suhag
- Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano, Italy
| | - Nitya Sharma
- Food and Bioprocess Engineering Laboratory, Centre for Rural Development and Technology, Indian Institute of Technology Delhi, New Delhi 110016, India
| | - Vivek Saurabh
- Division of Food Science and Postharvest Technology, ICAR—Indian Agricultural Research Institute, New Delhi 110012, India
| | - Veena Paul
- Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi 221005, India
| | - Manoj Kumar
- Chemical and Biochemical Processing Division, ICAR—Central Institute for Research on Cotton Technology, Mumbai 400019, India
| | - Raman Selvakumar
- Centre for Protected Cultivation Technology, ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi 110012, India
| | - Shirani Gamlath
- CASS Food Research Centre, School of Exercise and Nutrition Sciences, Deakin University, Burwood, VIC 3125, Australia
| | - Madhu Kamle
- Applied Microbiology Laboratory, Department of Forestry, North Eastern Regional Institute of Science and Technology, Nirjuli 791109, India
| | - Hesham Ali El Enshasy
- Institute of Bioproduct Development, Universiti Teknologi Malaysia (UTM), Skudai 81310, Malaysia
- City of Scientific Research and Technology Applications, New Burg Al Arab, Alexandria 21934, Egypt
| | - Jawahir A. Mokhtar
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University Hospital, Jeddah 21589, Saudi Arabia
- Vaccines and Immunotherapy Unit, King Fahad Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Steve Harakeh
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Yousef Abdul Latif Jameel Scientific Chair of Prophetic Medicine Application, Faculty of Medicine (FM), King Abdulaziz University, Jeddah 21589, Saudi Arabia
| |
Collapse
|
29
|
Adácsi C, Kovács S, Pócsi I, Pusztahelyi T. Elimination of Deoxynivalenol, Aflatoxin B1, and Zearalenone by Gram-Positive Microbes (Firmicutes). Toxins (Basel) 2022; 14:toxins14090591. [PMID: 36136529 PMCID: PMC9501497 DOI: 10.3390/toxins14090591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Mycotoxin contaminations in the feed and food chain are common. Either directly or indirectly, mycotoxins enter the human body through the consumption of food of plant and animal origin. Bacteria with a high mycotoxin elimination capability can reduce mycotoxin contamination in feed and food. Four Gram-positive endospore-forming bacteria (Bacillus thuringiensis AMK10/1, Lysinibacillus boronitolerans AMK9/1, Lysinibacillus fusiformis AMK10/2, and Rummeliibacillus suwonensis AMK9/2) were isolated from fermented forages and tested for their deoxynivalenol (DON), aflatoxin B1 (AFB1), and zearalenone (ZEA) elimination potentials. Notably, the contribution of bacterial cell wall fractions to the observed outstanding ZEA elimination rates was demonstrated; however, the ZEA elimination differed considerably within the tested group of Gram-positive bacteria. It is worth noting that the purified cell wall of L. boronitolerans AMK9/1, L. fusiformis AMK10/2 and B. thuringiensis AMK10/1 were highly efficient in eliminating ZEA and the teichoic acid fractions of B. thuringiensis AMK10/1, and L. fusiformis AMK10/2 could also be successfully used in ZEA binding. The ZEA elimination capacity of viable R. suwonensis AMK9/2 cells was outstanding (40%). Meanwhile, R. suwonensis AMK9/2 and L. boronitolerans AMK9/1 cells produced significant esterase activities, and ZEA elimination of the cell wall fractions of that species did not correlate with esterase activity. DON and AFB1 binding capabilities of the tested bacterial cells and their cell wall fractions were low, except for B. thuringiensis AMK10/1, where the observed high 64% AFB1 elimination could be linked to the surface layer (S-layer) fraction of the cell wall.
Collapse
Affiliation(s)
- Cintia Adácsi
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, Böszörményi Str. 138, H-4032 Debrecen, Hungary
| | - Szilvia Kovács
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Böszörményi Str. 138, H-4032 Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Egyetem Tér 1, H-4032 Debrecen, Hungary
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Böszörményi Str. 138, H-4032 Debrecen, Hungary
- Correspondence: ; Tel.: +36-20-210-9491
| |
Collapse
|
30
|
Yuan XY, Li JY, Zhi QQ, Chi SD, Qu S, Luo YF, He ZM. SfgA Renders Aspergillus flavus More Stable to the External Environment. J Fungi (Basel) 2022; 8:jof8060638. [PMID: 35736121 PMCID: PMC9224668 DOI: 10.3390/jof8060638] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 02/04/2023] Open
Abstract
sfgA is known as a key negative transcriptional regulator gene of asexual sporulation and sterigmatocystin production in Aspergillus nidulans. However, here, we found that the homolog sfgA gene shows a broad and complex regulatory role in governing growth, conidiation, sclerotia formation, secondary metabolism, and environmental stress responses in Aspergillus flavus. When sfgA was deleted in A. flavus, the fungal growth was slowed, but the conidiation was significantly increased, and the sclerotia formation displayed different behavior at different temperatures, which increased at 30 °C but decreased at 36 °C. In addition, sfgA regulated aflatoxin biosynthesis in a complex way that was associated with the changes in cultured conditions, and the increased production of aflatoxin in the ∆sfgA mutant was associated with a decrease in sclerotia size. Furthermore, the ∆sfgA mutant exhibited sensitivity to osmotic, oxidative, and cell wall stresses but still produced dense conidia. Transcriptome data indicated that numerous development- and secondary-metabolism-related genes were expressed differently when sfgA was deleted. Additionally, we also found that sfgA functions downstream of fluG in A. flavus, which is consistent with the genetic position in FluG-mediated conidiation in A. nidulans. Collectively, sfgA plays a critical role in the development, secondary metabolism, and stress responses of A. flavus, and sfgA renders A. flavus more stable to the external environment.
Collapse
Affiliation(s)
- Xiao-Yu Yuan
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Jie-Ying Li
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Qing-Qing Zhi
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Sheng-Da Chi
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Su Qu
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
| | - Yan-Feng Luo
- Guangdong Jinyinshan Environmental Protection Technology Co., Ltd., Guangzhou 510705, China;
| | - Zhu-Mei He
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Science, Sun Yat-sen University, Guangzhou 510275, China; (X.-Y.Y.); (J.-Y.L.); (Q.-Q.Z.); (S.-D.C.); (S.Q.)
- Correspondence:
| |
Collapse
|
31
|
Wang X, Zhao Y, Qi X, Zhao T, Wang X, Ma F, Zhang L, Zhang Q, Li P. Quantitative analysis of metabolites in the aflatoxin biosynthesis pathway for early warning of aflatoxin contamination by UHPLC-HRMS combined with QAMS. JOURNAL OF HAZARDOUS MATERIALS 2022; 431:128531. [PMID: 35220124 DOI: 10.1016/j.jhazmat.2022.128531] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/15/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Aflatoxins seriously threaten human health and food safety, and early warning benefits the reasonable use of control measures to reduce aflatoxin contamination. In this study, a novel method for quantifying aflatoxins and their precursors in the aflatoxin biosynthesis pathway was developed by combining ultra-high performance liquid chromatography high-resolution mass spectrometry (UHPLC-HRMS) with quantitative analysis of multi-components by a single marker (QAMS). The stability of the relative correction factor (RCF) of QAMS was then systematically evaluated. The validation results showed that the relative deviation (RD) between QAMS and the external standard method (ESM) was less than 11.7%, indicating that the established QAMS method could replace ESM without the use of reference standards. This method was successfully employed to compare the time-course changes of metabolites in the aflatoxin biosynthesis pathway of Aspergillus flavus and Aspergillus parasitica. As a result, the precursors of (1'S,5'R)-5'-Hydroxyaverantin (HAVN) and Versicolorin B (VerB) could be used as potential markers for the early warning of aflatoxin contamination. This study provided a quantitative method of aflatoxins and their precursors in the biosynthesis pathway, and may serve as a reference for the extension of quantitative studies on other metabolic pathways.
Collapse
Affiliation(s)
- Xiao Wang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Ya Zhao
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Xin Qi
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China
| | - Tiantian Zhao
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China
| | - Xiupin Wang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China
| | - Fei Ma
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China
| | - Liangxiao Zhang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China; Hubei Hongshan Laboratory, Wuhan 430070, China.
| | - Qi Zhang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China; Hubei Hongshan Laboratory, Wuhan 430070, China
| | - Peiwu Li
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China; Quality Inspection and Test Center for Oilseed Products, Ministry of Agriculture and Rural Affairs, Wuhan 430062, China; Hubei Hongshan Laboratory, Wuhan 430070, China.
| |
Collapse
|
32
|
Şen L, Civil O. Presence of aflatoxins in hazelnut paste in Turkey and a risk assessment study. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2022; 39:1474-1486. [PMID: 35652906 DOI: 10.1080/19440049.2022.2081367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Two hundred and two hazelnut paste samples from various hazelnut processing plants in the Black Sea Region of Turkey were analysed for the incidence of aflatoxins (AFs) by liquid chromatography coupled with fluorescence detection (LC-FLD). All 202 (100%) hazelnut paste samples were contaminated with various AFs ranged from 0.17 to 12.96 µg kg-1. AF contamination level of four (1.98%) samples exceeded legal limits. Risk assessment for hazelnut paste was determined by using AF incidence results, and the margin of exposure (MOE) and hepatocellular carcinoma (HCC) risk approach were applied. For the adult Turkish population (15+ years age group), the average lower bound (LB) and upper bound (UB) exposure levels for aflatoxin B1 (AFB1) and total aflatoxins (AFT) were 0.0106-0.0107 ng kg-1 body weight (bw) per day and 0.0250 ng kg-1 bw per day, respectively. MOE estimates for mean and 95th percentile exposures to AFB1 for hazelnut paste were higher than 10,000, which indicates no potential health concern for Turkish adults. HCC for the Turkish population was 0.00023 cases per 100,000 people per year. The study indicates that Turkish population is not under this toxicological risk when consuming hazelnut paste containing food products.
Collapse
Affiliation(s)
- Levent Şen
- Food Engineering Department, Engineering Faculty, Giresun University, Giresun, Turkey
| | - Onur Civil
- Food Engineering Department, Engineering Faculty, Giresun University, Giresun, Turkey
| |
Collapse
|
33
|
Lv H, Zhang J, Xue Y, Li S, Sun X, Jia J, Bi H, Wang S, Su H, Zhu M, Wang H, Hong K, Li X. Two New Austocystin Analogs from the Marine-Derived Fungus Aspergillus sp. WHUF05236. Chem Biodivers 2022; 19:e202200207. [PMID: 35419971 DOI: 10.1002/cbdv.202200207] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/13/2022] [Indexed: 11/09/2022]
Abstract
Two new austocystin analogs, austocystin P (1) and austocystin Q (2), along with fourteen known compounds (3-16) were isolated from the fermentation extract of Aspergillus sp. WHUF05236. The planar structures of 1 and 2 were elucidated through 1D, 2D NMR and MS analyses. Their absolute configurations were determined by the time-dependent density functional (TDDFT)-ECD calculation. Compounds 3, 11, and 12 exhibited antimicrobial activities against Helicobacter pylori with MIC values ranging from 20.00 to 43.47 μM. Compounds 3, 6, and 7 showed cytotoxicities against the human colon cancer cell lines Hct-116 with IC50 values of 101.79, 65.46, and 36.72 μM, respectively.
Collapse
Affiliation(s)
- Huawei Lv
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Jinkun Zhang
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Yaxin Xue
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, P. R. China
| | - Songwei Li
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Xiaoyu Sun
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, P. R. China
| | - Jia Jia
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, 211166, Nanjing, P. R. China
| | - Hongkai Bi
- Department of Pathogen Biology & Jiangsu Key Laboratory of Pathogen Biology, Nanjing Medical University, 211166, Nanjing, P. R. China
| | - Shoubao Wang
- Beijing Key Laboratory of Drug Target Research and New Drug Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences, 100050, Beijing, P. R. China
| | - Haibo Su
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Mengdi Zhu
- Research Center of Analysis and Measurement, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Hong Wang
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| | - Kui Hong
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, School of Pharmaceutical Sciences, Wuhan University, 430071, Wuhan, P. R. China
| | - Xingnuo Li
- College of Pharmaceutical Science & Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Key Laboratory of Marine Fishery Resources Exploitment & Utilization of Zhejiang Province, Zhejiang University of Technology, 310014, Hangzhou, P. R. China
| |
Collapse
|
34
|
Chen G, Fang Q, Liao Z, Xu C, Liang Z, Liu T, Zhong Q, Wang L, Fang X, Wang J. Detoxification of Aflatoxin B1 by a Potential Probiotic Bacillus amyloliquefaciens WF2020. Front Microbiol 2022; 13:891091. [PMID: 35620100 PMCID: PMC9127598 DOI: 10.3389/fmicb.2022.891091] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
Microbial degradation is considered as an attractive method to eliminate exposure to aflatoxin B1 (AFB1), the most toxic mycotoxin that causes great economic losses and brings a serious threat to human and animal health, in food and feed. In this study, Bacillus amyloliquefaciens WF2020, isolated from naturally fermented pickles, could effectively degrade AFB1 ranging from 1 to 8 μg/ml, and the optimum temperature and pH value were 37–45°C and 8.0, respectively. Moreover, B. amyloliquefaciens WF2020 was considered to be a potential probiotic due to the synthesis of active compounds, absence of virulence genes, susceptibility to various antibiotics, and enhanced lifespan of Caenorhabditis elegans. Extracellular enzymes or proteins played a major role in AFB1 degradation mediated by B. amyloliquefaciens WF2020 into metabolites with low or no mutagenicity and toxicity to C. elegans. AFB1 degradation by the cell-free supernatant was stable up to 70°C, with an optimal pH of 8.0, and the cell-free supernatant could still degrade AFB1 by 37.16% after boiling for 20 min. Furthermore, B. amyloliquefaciens WF2020 caused a slight defect in fungal growth and completely inhibited AFB1 production when co-incubated with Aspergillus flavus. Additionally, B. amyloliquefaciens WF2020 suppressed the expression of 10 aflatoxin pathway genes and 2 transcription factors (alfR and alfS), suggesting that B. amyloliquefaciens WF2020 might inhibit AFB1 synthesis in A. flavus. These results indicate that B. amyloliquefaciens WF2020 and/or its extracellular enzymes or proteins have a promising potential to be applied in protecting food and feed from AFB1 contamination.
Collapse
Affiliation(s)
- Guojun Chen
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Qian'an Fang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Zhenlin Liao
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Chunwei Xu
- Guangdong Moyanghua Grains and Oils Co., Ltd., Yangjiang, China
| | - Zhibo Liang
- Guangdong Moyanghua Grains and Oils Co., Ltd., Yangjiang, China
| | - Tong Liu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Qingping Zhong
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Li Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Xiang Fang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| | - Jie Wang
- Guangdong Provincial Key Laboratory of Food Quality and Safety, Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
35
|
Yaseen S, Hanano A. Quantitative PCR (qPCR) Reveals that the Aflatoxin-Free Pistachio Samples Can Be Potentially Contaminated with Fungal Materials. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-022-02327-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
36
|
Schamann A, Schmidt-Heydt M, Geisen R, Kulling SE, Soukup ST. Formation of B- and M-group aflatoxins and precursors by Aspergillus flavus on maize and its implication for food safety. Mycotoxin Res 2022; 38:79-92. [PMID: 35288866 PMCID: PMC9038868 DOI: 10.1007/s12550-022-00452-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 02/09/2022] [Accepted: 02/17/2022] [Indexed: 10/27/2022]
Abstract
Aflatoxins count to the most toxic known mycotoxins and are a threat to food safety especially in regions with a warm and humid climate. Contaminated food reaches consumers globally due to international trade, leading to stringent regulatory limits of aflatoxins in food. While the formation of aflatoxin (AF) B1 by the filamentous fungus Aspergillus flavus is well investigated, less is known about the formation kinetics of its precursors and further aflatoxins. In this study, autoclaved maize kernels were inoculated with A. flavus and incubated at 25 °C for up to 10 days. Aflatoxins and precursors were analyzed by a validated UHPLC-MS method. Additional to AFB1 and AFB2, AFM1 and AFM2 were detected, confirming the ability of the formation of M-group aflatoxins on cereals by A. flavus. The measured relative levels of AFB2, AFM1, and AFM2 on maize compared to the level of AFB1 (mean of days 5, 7, and 10 of incubation) were 3.3%, 1.5%, and 0.2%, respectively. The occurrence and kinetics of the measured aflatoxins and their precursors sterigmatocystin, O-methylsterigmatocystin, 11-hydroxy-O-methylsterigmatocystin, aspertoxin, and 11-hydroxyaspertoxin (group 1) as well as of dihydrosterigmatocystin and dihydro-O-methylsterigmatocystin (group 2) supported the so far postulated biosynthetic pathway. Remarkable high levels of O-methylsterigmatocystin and aspertoxin (17.4% and 4.9% compared to AFB1) were found, raising the question about the toxicological relevance of these intermediates. In conclusion, based on the study results, the monitoring of O-methylsterigmatocystin and aspertoxin as well as M-group aflatoxins in food is recommended.
Collapse
Affiliation(s)
- Alexandra Schamann
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut (MRI) - Federal Research Institute of Nutrition and Food, Karlsruhe, Germany
| | - Markus Schmidt-Heydt
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut (MRI) - Federal Research Institute of Nutrition and Food, Karlsruhe, Germany
| | - Rolf Geisen
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut (MRI) - Federal Research Institute of Nutrition and Food, Karlsruhe, Germany
| | - Sabine E Kulling
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut (MRI) - Federal Research Institute of Nutrition and Food, Karlsruhe, Germany
| | - Sebastian T Soukup
- Department of Safety and Quality of Fruit and Vegetables, Max Rubner-Institut (MRI) - Federal Research Institute of Nutrition and Food, Karlsruhe, Germany.
| |
Collapse
|
37
|
Abstract
Aspergillus flavusaflR, a gene encoding a Zn(II)2Cys6 DNA-binding domain, is an important transcriptional regulator of the aflatoxin biosynthesis gene cluster. Our previous results of Gene ontology (GO) analysis for the binding sites of AflR in A. flavus suggest that AflR may play an integrative regulatory role. In this study the ΔaflR and overexpression (OE) strains based on the well-established double-crossover recombinational technique were constructed to investigate the integrative function of the aflR gene in A. flavus. The disruption of aflR severely affected the aflatoxin biosynthetic pathway, resulting in a significant decrease in aflatoxin production. The aflatoxin B1 (AFB1) of the ΔaflR strain was 180 ng/mL and aflatoxin B2 (AFB2) was 2.95 ng/mL on YES medium for 5 days, which was 1/1,000 of that produced by the wild-type strain (WT). In addition, the ΔaflR strain produced relatively sparse conidia and a very small number of sclerotia. On the seventh day, the sclerotia yield on each plate of the WT and OE strains exceeded 1,000, while the sclerotial formation of the ΔaflR strain was not detected until 14 days. However, the biosynthesis of cyclopiazonic acid (CPA) was not affected by aflR gene disruption. Transcriptomic analysis of the ΔaflR strain grown on potato dextrose agar (PDA) plates at 0 h, 24 h, and 72 h showed that expression of clustering genes involved in the biosynthesis of aflatoxin was significantly downregulated. Meanwhile, the ΔaflR strain compared with the WT strain showed significant expression differences in genes involved in spore germination, sclerotial development, and carbohydrate metabolism compared to the WT. The results demonstrated that the A. flavusaflR gene also played a positive role in the fungal growth and development in addition to aflatoxin biosynthesis. IMPORTANCE Past studies of the A. flavusaflR gene and its orthologues in related Aspergillus species were solely focused on their roles in secondary metabolism. In this study, we used the ΔaflR and OE strains to demonstrate the role of aflR in growth and development of A. flavus. For the first time, we confirmed that the ΔaflR strain also was defective in production of conidia and sclerotia, asexual propagules of A. flavus. Our transcriptomic analysis further showed that genes involved in spore germination, sclerotial development, aflatoxin biosynssssthesis, and carbohydrate metabolism exhibited significant differences in the ΔaflR strain compared with the WT strain. Our study indicates that AflR not only plays an important role in regulating aflatoxin synthesis but also in playing a positive role in the conidial formation and sclerotial development in A. flavus. This study reveals the critical and positive role of the aflR gene in fungal growth and development, and provides a theoretical basis for the genetic studies of other aspergilli.
Collapse
|
38
|
Natarajan S, Balachandar D, Senthil N, Paranidharan V. Interaction of water activity and temperature on growth, gene expression, and aflatoxin B 1 production in Aspergillus flavus on Indian senna (Cassia angustifolia Vahl.). Int J Food Microbiol 2022; 361:109457. [PMID: 34742145 DOI: 10.1016/j.ijfoodmicro.2021.109457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 10/09/2021] [Accepted: 10/22/2021] [Indexed: 11/19/2022]
Abstract
Senna (Cassia angustifolia Vahl.) is a medicinal crop with laxative properties, and it has significant demand in the global pharmaceutical market. Senna pods are highly susceptible to aflatoxin contamination, and the successful export of pods is hindered due to the regulatory limits of importing countries. The senna pod water activity (aw) from harvest to storage is the key factor determining AFB1 accumulation. The temperature conditions from field to warehouse also interact with pod aw, which influences fungal growth and AFB1 production. The determination of an ideal combination of aw and temperature led to the assessment of the critical control point for AFB1 synthesis in senna. Hence, this study aimed to evaluate the influence of aw (0.99, 0.96, 0.93, 0.90, and 0.87 aw) and temperature (20, 28, and 37 °C) on fungal growth, gene expression (aflR and aflS), and AFB1 production by A. flavus in senna agar medium. The fungus showed the longest lag time (7.7 days) at 20 °C with 0.87 aw. We observed that 0.96 aw (P < 0.01) was optimum for the diametric growth rate at 28 and 37 °C. However, the peak expression of regulatory genes (aflR and aflS) and the maximum AFB1 production were observed only at 28 °C (0.96 aw). The highest growth rate occurred at 37 °C, which did not favor the expression of genes and AFB1 production. However, at 28 °C, it positively correlated with gene expression and AFB1 production. The suppressed expression of regulatory genes and a trace amount of aflatoxin B1 were found at 20 °C with all the tested aw. In our experiments, the low aw (0.87 and 0.90 aw) suppressed the fungal growth, gene expression, and AFB1 production of A. flavus at all of the tested temperatures (20, 28, and 37 °C). The rapid drying of senna pods with a low water activity (≤0.87 aw) and storage at low temperature (20 °C) are ideal conditions to avoid AFB1 and ensure the quality of produce for export.
Collapse
Affiliation(s)
- Subramani Natarajan
- Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003, India
| | - Dananjeyan Balachandar
- Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003, India
| | - Natesan Senthil
- Department of Plant Molecular Biology and Bioinformatics, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003, India
| | - Vaikuntavasan Paranidharan
- Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu 641 003, India.
| |
Collapse
|
39
|
Reis T, Tralamazza S, Coelho E, Zorzete P, Corrêa B. Early expression of the aflatoxin gene cluster in Aspergillus nomiae isolated from Brazil nut. Toxicon 2022; 209:36-42. [DOI: 10.1016/j.toxicon.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 12/30/2021] [Accepted: 01/21/2022] [Indexed: 10/19/2022]
|
40
|
Kumar A, Singh PP, Prakash B. Assessing the efficacy of chitosan nanomatrix incorporated with Cymbopogon citratus (DC.) Stapf essential oil against the food-borne molds and aflatoxin B 1 production in food system. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 180:105001. [PMID: 34955184 DOI: 10.1016/j.pestbp.2021.105001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/15/2021] [Accepted: 11/20/2021] [Indexed: 06/14/2023]
Abstract
The chitosan nanomatrix incorporated with Cymbopogon citratus essential oil (Ne-CcEO) possess enhanced efficacy against the food-borne molds and aflatoxin B1 production compared to free essential oil. The CcEO was encapsulated inside the chitosan nanomatrix with an average size 147.41 ± 16.18 nm and characterized by Scanning electron microscopy, Fourier transforms infrared spectroscopy, and X-ray diffraction assay. The encapsulation efficiency and loading capacity were ranged between (41.68-76.78%) and (5.3-8.80%). The biochemical and in-silico analysis results revealed the interference in functioning of membrane integrity, mitochondrial membrane potential, antioxidant defense, carbon source metabolism, methylglyoxal, and laeA gene in response to treatment of Ne-CcEO (0.5 μl/ml). In addition, Ne-CcEO significantly protects the deterioration of Pennisetum glaucum (L.) R. Br. seed samples by A. flavus, aflatoxin B1 contamination, and lipid peroxidation. The Ne-CcEO could be considered as promising antifungal additives for the control of food-borne molds and aflatoxin B1 contamination in the food system.
Collapse
Affiliation(s)
- Akshay Kumar
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Prem Pratap Singh
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Bhanu Prakash
- Centre of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
| |
Collapse
|
41
|
Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Vleminckx C, Wallace H, Rose M, Cottrill B, Lundebye AK, Metzler M, Christodoulidou A, Hogstrand C. Assessment of an application on a detoxification process of groundnut press cake for aflatoxins by ammoniation. EFSA J 2021; 19:e07035. [PMID: 34976165 PMCID: PMC8690986 DOI: 10.2903/j.efsa.2021.7035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Following a request from the European Commission, the EFSA Panel on Contaminants in the Food Chain (CONTAM) provided a scientific opinion on an application for a detoxification process of groundnut press cake for aflatoxins by ammoniation. Specifically, it is required that the feed decontamination process is compliant with the acceptability criteria specified in the Commission Regulation (EU) 2015/786 of 19 May 2015. The CONTAM Panel assessed the data provided by the feed business operator with respect to the efficacy of the process to remove the contaminant from groundnut press cake batches and on information demonstrating that the process does not adversely affect the characteristics and the nature of the product. Although according to the literature the process may be able to reduce aflatoxin levels below the legal limits, the Panel concluded that the proposed decontamination process, on the basis of the experimental data submitted by the feed business operator, cannot be confirmed for compliance with the acceptability criteria provided for in Commission Regulation (EU) 2015/786 of 19 May 2015. The Panel recommended sufficient sample testing before and after the process, under the selected conditions, to ensure that the process is reproducible and reliable and to demonstrate that the detoxification is not reversible. In addition, genotoxicity testing of extracts of the treated feedingstuff and of the identified degradation products would be necessary. Finally, information on the transfer rate of AFB1 to AFM1 excretion in milk for animals fed the ammoniated product, in comparison to the starting material and on the ammoniation process changes of the nutritional values of the feed material should be provided.
Collapse
|
42
|
Yao L, Ban F, Peng S, Xu D, Li H, Mo H, Hu L, Zhou X. Exogenous Iron Induces NADPH Oxidases-Dependent Ferroptosis in the Conidia of Aspergillus flavus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:13608-13617. [PMID: 34747604 DOI: 10.1021/acs.jafc.1c04411] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aspergillus flavus is saprophytic soil fungus that contaminates seed crops with the carcinogenic secondary metabolite aflatoxin, posing a significant threat to humans and animals. Ferrous sulfate is a common iron supplement that is used to the treatment of iron-deficiency anemia. Here, we identified an unexpected inhibitory role of ferrous sulfate on A. flavus. With specific fluorescent dyes, we detected several conidial ferroptosis hallmarks in conidia under the treatment of 1 mM Fe2+, including nonapoptosis necrosis, iron-dependent, lipid peroxide accumulation, and ROS burst. However, unlike traditional ferroptosis in mammals, Fe2+ triggered conidial ferroptosis in A. flavus was regulated by NADPH oxidase (NOXs) activation instead of Fenton reaction. Transcriptomic and some other bioinformatics analyses showed that NoxA in A. flavus might be a potential target of Fe2+, and thus led to the occurrence of conidial ferroptosis. Furthermore, noxA deletion mutant was constructed, and both ROS generation and conidial ferroptosis in ΔnoxA was reduced when exposed to Fe2+. Taken together, our study revealed an exogenous Fe2+-triggered conidial ferroptosis pathway mediated by NoxA of A. flavus, which greatly contributes to the development of an alternative strategy to control this pathogen.
Collapse
Affiliation(s)
- Lishan Yao
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Fangfang Ban
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Shurui Peng
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Dan Xu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Hongbo Li
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Haizhen Mo
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Liangbin Hu
- School of Food and Biological Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, Connecticut 06269, United States
| |
Collapse
|
43
|
Vlajkov V, Grahovac M, Budakov D, Loc M, Pajčin I, Milić D, Novaković T, Grahovac J. Distribution, Genetic Diversity and Biocontrol of Aflatoxigenic Aspergillus flavus in Serbian Maize Fields. Toxins (Basel) 2021; 13:toxins13100687. [PMID: 34678980 PMCID: PMC8540170 DOI: 10.3390/toxins13100687] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/04/2021] [Accepted: 08/04/2021] [Indexed: 11/16/2022] Open
Abstract
Maize is one of the leading export products in the Republic of Serbia. As a country where economic development depends on agriculture, maize production plays a critical role as a crop of strategic importance. Potential aflatoxin contamination of maize poses a risk to food and feed safety and tremendous economic losses. No aflatoxin contamination of maize samples harvested in 2019 and 2020 in different localities in the Republic of Serbia was detected by the Enzyme-Linked Immunosorbent Assay (ELISA) test and High-Performance Liquid Chromatography (HPLC) method. On the other hand, the Cluster Amplification Patterns (CAP) analyses of the isolated Aspergillus flavus strains from 2019 maize samples confirmed the presence of key biosynthesis genes responsible for aflatoxin production. Artificial inoculation and subsequent HPLC analysis of the inoculated maize samples confirmed the high capacity of the A. flavus strains for aflatoxin production, pointing to a high risk of contamination under favorable conditions. Prevention of aflatoxin contamination is primarily based on A. flavus control, where biocontrol agents play a significant role as sustainable disease management tools. In this study, antagonistic activity screening of the novel strains belonging to the Bacillus genus indicated superior suppression of A. flavus strains by two Bacillus strains isolated from the rhizosphere of Phaseolus vulgaris.
Collapse
Affiliation(s)
- Vanja Vlajkov
- Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia; (I.P.); (J.G.)
- Correspondence: (V.V.); (M.G.)
| | - Mila Grahovac
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia; (D.B.); (M.L.); (D.M.); (T.N.)
- Correspondence: (V.V.); (M.G.)
| | - Dragana Budakov
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia; (D.B.); (M.L.); (D.M.); (T.N.)
| | - Marta Loc
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia; (D.B.); (M.L.); (D.M.); (T.N.)
| | - Ivana Pajčin
- Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia; (I.P.); (J.G.)
| | - Dragan Milić
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia; (D.B.); (M.L.); (D.M.); (T.N.)
| | - Tihomir Novaković
- Faculty of Agriculture, University of Novi Sad, Trg Dositeja Obradovića 8, 21000 Novi Sad, Serbia; (D.B.); (M.L.); (D.M.); (T.N.)
| | - Jovana Grahovac
- Faculty of Technology, University of Novi Sad, Bulevar Cara Lazara 1, 21000 Novi Sad, Serbia; (I.P.); (J.G.)
| |
Collapse
|
44
|
Mamo FT, Abate BA, Zheng Y, Nie C, He M, Liu Y. Distribution of Aspergillus Fungi and Recent Aflatoxin Reports, Health Risks, and Advances in Developments of Biological Mitigation Strategies in China. Toxins (Basel) 2021; 13:678. [PMID: 34678973 PMCID: PMC8541519 DOI: 10.3390/toxins13100678] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 12/24/2022] Open
Abstract
Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus Aspergillus flavus, which are abundantly distributed across agricultural commodities. AF contamination is receiving increasing attention by researchers, food producers, and policy makers in China, and several interesting review papers have been published, that mainly focused on occurrences of AFs in agricultural commodities in China. The goal of this review is to provide a wider scale and up-to-date overview of AF occurrences in different agricultural products and of the distribution of A. flavus across different food and feed categories and in Chinese traditional herbal medicines in China, for the period 2000-2020. We also highlight the health impacts of chronic dietary AF exposure, the recent advances in biological AF mitigation strategies in China, and recent Chinese AF standards.
Collapse
Affiliation(s)
- Firew Tafesse Mamo
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
- Ethiopian Biotechnology Institute, Addis Ababa 5954, Ethiopia;
| | | | - Yougquan Zheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
| | - Chengrong Nie
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
| | - Mingjun He
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
| | - Yang Liu
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
| |
Collapse
|
45
|
González-López NM, Huertas-Ortiz KA, Leguizamon-Guerrero JE, Arias-Cortés MM, Tere-Peña CP, García-Castañeda JE, Rivera-Monroy ZJ. Omics in the detection and identification of biosynthetic pathways related to mycotoxin synthesis. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:4038-4054. [PMID: 34486583 DOI: 10.1039/d1ay01017d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Mycotoxins are secondary metabolites that are known to be toxic to humans and animals. On the other hand, some mycotoxins and their analogues possess antioxidant as well as antitumor properties, which could be relevant in the fields of pharmaceutical analysis and food research. Omics techniques are a group of analytical tools applied in the biological sciences in order to study genes (genomics), mRNA (transcriptomics), proteins (proteomics), and metabolites (metabolomics). Omics have become a vital tool in the field of mycotoxins, especially contributing to the identification of biomarkers with potential use for the detection of mycotoxigenic species and the gathering of information about the biosynthetic pathways of mycotoxins in different environments. This approach has provided tools for the development of prevention strategies and control measures for different mycotoxins. Additionally, research has revealed important information about the impact of global warming and climate change on the prevalence of mycotoxin issues in society. In the context of foodomics, the aim is to apply omics techniques in order to ensure food safety. The objective of the present review is to determine the state of the art regarding the development of analytical techniques based on omics in the identification of biosynthetic pathways related to mycotoxin synthesis.
Collapse
Affiliation(s)
| | - Kevin Andrey Huertas-Ortiz
- Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 45 No 26-85, Building 450, Bogotá, Colombia.
| | | | | | | | | | - Zuly Jenny Rivera-Monroy
- Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 45 No 26-85, Building 450, Bogotá, Colombia.
| |
Collapse
|
46
|
Buitimea-Cantúa GV, Magaña-Barajas E, Buitimea-Cantúa NE, Leija Gutiérrez HM, Del Refugio Rocha-Pizaña M, Rosas-Burgos EC, Hernández-Morales A, Molina-Torres J. Down-regulation of aflatoxin biosynthetic genes in Aspergillus parasiticus by Heliopsis longipes roots and affinin for reduction of aflatoxin production. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2021; 56:899-908. [PMID: 34487477 DOI: 10.1080/03601234.2021.1974273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Affinin present in Heliopsis longipes roots has been identified as an anti-aflatoxin molecule. However, its mechanism of action has yet to be clarified. Aflatoxins biosynthesis involves not less than 27 enzymatic reactions. In this work, the genes aflG, aflH, aflI, aflK, aflL, aflM, aflO, aflP, and aflQ of the aflatoxins cluster and the aflS gene encoding an internal regulatory factor involved in aflatoxins biosynthesis in Aspergillus parasiticus, were studied by qRT-PCR. Results demonstrated that ethanolic extract of H. longipes roots and affinin inhibit aflatoxin biosynthesis and fungal growth in a dose-dependent manner. At 300 µg/mL, ethanolic extract and affinin presented the highest inhibition of radial growth (86% and 94%) and aflatoxin production (68% and 80%). The qRT-PCR analysis demonstrated that nine tested genes were down-regulated by affinin and ethanolic extract. The most down-regulated was the aflK, a gene that encodes an enzyme cyclase with double function during the aflatoxin biosynthesis. While no significant down-regulation was obtaining for aflH gene. Exposure to affinin also resulted in decreased transcript levels of the internal regulator factor aflS. Based on our results, a model showing the regulatory mechanism in aflatoxin biosynthesis and its role in gene expression was proposed. In conclusion, affinin modulates the expression of several aflatoxin biosynthetic genes, leading to mycotoxin biosynthesis inhibition. Therefore, H. longipes roots is a suitable candidate to developed control strategies via lowering gene expressions as a future perspective in reducing aflatoxin contamination.
Collapse
Affiliation(s)
- Génesis V Buitimea-Cantúa
- Tecnologico de Monterrey, Centro de Biotecnología-FEMSA, Escuela de Ingeniería y Ciencias, Monterrey, Nuevo León, México
- Departamento de Biotecnología y Bioquímica, CINVESTAV, Irapuato, Guanajuato, México
| | - Elisa Magaña-Barajas
- Programa de Ingeniería en Tecnologías de Alimentos, Universidad Estatal de Sonora, Hermosillo, México
| | - Nydia E Buitimea-Cantúa
- Tecnologico de Monterrey, Centro de Biotecnología-FEMSA, Escuela de Ingeniería y Ciencias, Monterrey, Nuevo León, México
| | - Héctor Manuel Leija Gutiérrez
- Universidad Autónoma de Nuevo León, CICFM-Facultad de Ciencias Físico Matemáticas. San Nicolás de los Garza, NL, México
| | | | - Ema Carina Rosas-Burgos
- Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora, Hermosillo, Sonora, México
| | - Alejandro Hernández-Morales
- Facultad de Estudios Profesionales Zona Huasteca, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - Jorge Molina-Torres
- Departamento de Biotecnología y Bioquímica, CINVESTAV, Irapuato, Guanajuato, México
| |
Collapse
|
47
|
A review of mycotoxin biosynthetic pathways: associated genes and their expressions under the influence of climatic factors. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
48
|
Updates on the Functions and Molecular Mechanisms of the Genes Involved in Aspergillus flavus Development and Biosynthesis of Aflatoxins. J Fungi (Basel) 2021; 7:jof7080666. [PMID: 34436205 PMCID: PMC8401812 DOI: 10.3390/jof7080666] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 08/08/2021] [Accepted: 08/10/2021] [Indexed: 12/13/2022] Open
Abstract
Aspergillus flavus (A. flavus) is a ubiquitous and opportunistic fungal pathogen that causes invasive and non-invasive aspergillosis in humans and animals. This fungus is also capable of infecting a large number of agriculture crops (e.g., peanuts, maze, cotton seeds, rice, etc.), causing economic losses and posing serious food-safety concerns when these crops are contaminated with aflatoxins, the most potent naturally occurring carcinogens. In particular, A. flavus and aflatoxins are intensely studied, and they continue to receive considerable attention due to their detrimental effects on humans, animals, and crops. Although several studies have been published focusing on the biosynthesis of the aforementioned secondary metabolites, some of the molecular mechanisms (e.g., posttranslational modifications, transcription factors, transcriptome, proteomics, metabolomics and transcriptome, etc.) involved in the fungal development and aflatoxin biosynthesis in A. flavus are still not fully understood. In this study, a review of the recently published studies on the function of the genes and the molecular mechanisms involved in development of A. flavus and the production of its secondary metabolites is presented. It is hoped that the information provided in this review will help readers to develop effective strategies to reduce A. flavus infection and aflatoxin production.
Collapse
|
49
|
Aflatoxin Biosynthesis, Genetic Regulation, Toxicity, and Control Strategies: A Review. J Fungi (Basel) 2021; 7:jof7080606. [PMID: 34436145 PMCID: PMC8397101 DOI: 10.3390/jof7080606] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 07/19/2021] [Accepted: 07/22/2021] [Indexed: 12/24/2022] Open
Abstract
Aflatoxins (AFs) are highly toxic and cancer-causing compounds, predominantly synthesized by the Aspergillus species. AFs biosynthesis is a lengthy process that requires as minimum as 30 genes grouped inside 75 kilobytes (kB) of gene clusters, which are regulated by specific transcription factors, including aflR, aflS, and some general transcription factors. This paper summarizes the status of research on characterizing structural and regulatory genes associated with AF production and their roles in aflatoxigenic fungi, particularly Aspergillus flavus and A. parasiticus, and enhances the current understanding of AFs that adversely affect humans and animals with a great emphasis on toxicity and preventive methods.
Collapse
|
50
|
Ma L, Li X, Ma X, Yu Q, Yu X, Liu Y, Nie C, Zhang Y, Xing F. The Regulatory Mechanism of Water Activities on Aflatoxins Biosynthesis and Conidia Development, and Transcription Factor AtfB Is Involved in This Regulation. Toxins (Basel) 2021; 13:toxins13060431. [PMID: 34205815 PMCID: PMC8235239 DOI: 10.3390/toxins13060431] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/02/2021] [Accepted: 06/18/2021] [Indexed: 12/22/2022] Open
Abstract
Peanuts are frequently infected by Aspergillus strains and then contaminated by aflatoxins (AF), which brings out economic losses and health risks. AF production is affected by diverse environmental factors, especially water activity (aw). In this study, A. flavus was inoculated into peanuts with different aw (0.90, 0.95, and 0.99). Both AFB1 yield and conidia production showed the highest level in aw 0.90 treatment. Transcriptional level analyses indicated that AF biosynthesis genes, especially the middle- and later-stage genes, were significantly up-regulated in aw 0.90 than aw 0.95 and 0.99. AtfB could be the pivotal regulator response to aw variations, and could further regulate downstream genes, especially AF biosynthesis genes. The expressions of conidia genes and relevant regulators were also more up-regulated at aw 0.90 than aw 0.95 and 0.99, suggesting that the relative lower aw could increase A. flavus conidia development. Furthermore, transcription factors involved in sexual development and nitrogen metabolism were also modulated by different aw. This research partly clarified the regulatory mechanism of aw on AF biosynthesis and A. flavus development and it would supply some advice for AF prevention in food storage.
Collapse
Affiliation(s)
- Longxue Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Xu Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Xiaoyun Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
| | - Qiang Yu
- Qingdao Tianxiang Foods Group Co., Qingdao 266737, China; (Q.Y.); (X.Y.)
| | - Xiaohua Yu
- Qingdao Tianxiang Foods Group Co., Qingdao 266737, China; (Q.Y.); (X.Y.)
| | - Yang Liu
- School of Food Science and Engineering, Foshan University, Foshan 528231, China; (Y.L.); (C.N.)
| | - Chengrong Nie
- School of Food Science and Engineering, Foshan University, Foshan 528231, China; (Y.L.); (C.N.)
| | - Yinglong Zhang
- Shandong Institute of Commerce and Technology, Jinan 250103, China
- Correspondence: (Y.Z.); (F.X.)
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (L.M.); (X.L.); (X.M.)
- Correspondence: (Y.Z.); (F.X.)
| |
Collapse
|