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Antifungal and Aflatoxin-Reducing Activity of β-Glucan Isolated from Pichia norvegensis Grown on Tofu Wastewater. Foods 2021; 10:foods10112619. [PMID: 34828900 PMCID: PMC8618602 DOI: 10.3390/foods10112619] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/02/2022] Open
Abstract
Yeast can be isolated from tofu wastewater and the cell wall in the form of β-glucan can act as a natural decontaminant agent. This study aimed to isolate and characterize native yeast from tofu wastewater, which can be extracted to obtain β-glucan and then identify the yeast and its β-glucan activity regarding antifungal ability against Aspergillus flavus and aflatoxin-reducing activity towards aflatoxin B1 (AFB1) and B2 (AFB2). Tofu wastewater native yeast was molecularly identified, and the growth observed based on optical density for 96 h and the pH also measured. β-glucan was extracted from native yeast cell walls with the acid-base method and then the inhibition activity towards A. flavus was tested using the well diffusion method and microscopic observation. AFB1 and AFB2 reduction were identified using HPLC LC-MS/MS. The results showed that the native yeast isolated was Pichia norvegensis with a β-glucan yield of 6.59%. Pichia norvegensis and its β-glucan showed an inhibition zone against Aspergillus flavus of 11.33 ± 4.93 and 7.33 ± 3.51 mm, respectively. Total aflatoxin-reducing activity was also shown by Pichia norvegensis of 26.85 ± 2.87%, and β-glucan of 27.30 ± 1.49%, while AFB1- and AFB2-reducing activity by Pichia norvegensis was 36.97 ± 3.07% and 27.13 ± 1.69%, and β-glucan was 27.13 ± 1.69% and 32.59 ± 4.20%, respectively.
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Nleya N, Ngoma L, Adetunji MC, Mwanza M. Biodiversity of Aflatoxigenic Aspergillus Species in Dairy Feeds in Bulawayo, Zimbabwe. Front Microbiol 2021; 11:599605. [PMID: 33552013 PMCID: PMC7859627 DOI: 10.3389/fmicb.2020.599605] [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: 08/27/2020] [Accepted: 12/11/2020] [Indexed: 11/17/2022] Open
Abstract
The presence of molds, especially certain species of Aspergillus, in food commodities may contribute to aflatoxin contamination. The aim of this study was to determine the biodiversity of Aspergillus species in dairy feeds from farms in select locations in Zimbabwe and assess their aflatoxin production potential using a polyphasic approach. A total of 96 feed samples were collected, which consisted of dairy feed concentrate, mixed ration, brewers’ spent grain, and grass from 13 farms during the dry season (August–October, 2016) and the following rainy season (January–March, 2017). A total of 199 presumptive isolates representing four sections from genus Aspergillus (Nigri, Fumigati, Flavi, and Circumdati) were recovered from the feeds. Section Flavi, which includes several aflatoxin producers, constituted 23% (n = 46) of the isolates. Species from this section were A. flavus, A. nomius, A. oryzae, A. parasiticus, and A. parvisclerotigenus, and 39 (84.4%) of these showed evidence of aflatoxin production in plate assays. Of the 46 section Flavi isolates examined, some lacked one or more of the five targeted aflatoxin cluster genes (aflD, aflR, aflS, aflM, and aflP). The presence of the five genes was as follows: aflD (76.9%), aflR (48.7%), aflS (74.4%), aflM (64.1%), and aflP (79.5%). This study highlights the species diversity of aflatoxigenic fungi that have the potential to contaminate different types of feed for dairy cows. Our findings underscore the importance of preventing contamination of feedstuffs by these fungi so that aflatoxins do not end up in the diets of consumers.
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Affiliation(s)
- Nancy Nleya
- Department of Animal Health, Northwest University, Mmabatho, South Africa.,Department of Applied Biology and Biochemistry, National University of Science and Technology, Bulawayo, Zimbabwe
| | - Lubanza Ngoma
- Department of Animal Health, Northwest University, Mmabatho, South Africa.,Food Security and Food Safety Niche Area, Northwest University, Mmabatho, South Africa
| | - Modupeade C Adetunji
- Department of Animal Health, Northwest University, Mmabatho, South Africa.,Department of Biological Sciences, Trinity University, Lagos, Nigeria
| | - Mulunda Mwanza
- Department of Animal Health, Northwest University, Mmabatho, South Africa.,Food Security and Food Safety Niche Area, Northwest University, Mmabatho, South Africa
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Korley Kortei N, Akomeah Agyekum A, Akuamoa F, Baffour VK, Wiisibie Alidu H. Risk assessment and exposure to levels of naturally occurring aflatoxins in some packaged cereals and cereal based foods consumed in Accra, Ghana. Toxicol Rep 2018; 6:34-41. [PMID: 30560059 PMCID: PMC6289905 DOI: 10.1016/j.toxrep.2018.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/19/2018] [Accepted: 11/27/2018] [Indexed: 11/20/2022] Open
Abstract
Majority 96.3% (26/27) of rice samples had total aflatoxin levels below international set limits (European Commission: 10 μg/kg). Almost half 45% (9/10) of the cereal based foods (mostly maize) were contaminated with aflatoxins and were above the set limits. None 0% (0/6) of the macaroni/spaghetti were contaminated with aflatoxins. AFG1 and AFG2 aflatoxin types were insignificant.
Aflatoxins are toxic secondary metabolites of fungal origin that contaminate agricultural commodities before, during and after harvest periods. A total of fifty-three (53) different foods (27 rice brands, 20 cereal based food brands and 6 pasta brands) were randomly obtained from the market and assessed for their different aflatoxin constitution (AFB1, AFB2, AFG1 and AFG2) as well as the total levels of the aflatoxins using High Performance Liquid Chromatography (HPLC) method. For the rice grain category, RS4 recorded the highest aflatoxin quantities of 65.77, 19.27, 1.02 μg/kg for AFB1, AFB2, AFG1 respectively and a total of 86.06 μg/kg which significantly differed (p < 0.05) from the other brands of foods. For the cereal based food category, CBS11 recorded the greatest quantities of 35.46, 4.92, 3.39 and 0.32 μg/kg for AFB1, AFB2, AFG1 and AFG2 respectively and a total of 45.1 μg/kg. For the pasta category, PS1 recorded the greatest quantities of 0.94 and 0.85 μg/kg for AFB1 and AFB2 respectively. Total aflatoxin quantities detected in some foods were above the acceptable limits set by the European Union which makes them unsafe and dangerous for human consumption. Recorded Estimated Daily Intakes (EDI) and Hazard Indices (HI) values were in the range of 3.9 × 10-3 – 0.899 and 3.9 × 10-4 - 0.0899 respectively. The risk was low since HI values obtained were less than 1.
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Affiliation(s)
- Nii Korley Kortei
- Department of Nutrition and Dietetics, School of Allied Health Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana
| | - Akwasi Akomeah Agyekum
- Applied Radiation Biology Centre, Ghana Atomic Energy Commission, P. O. Box AE 1, Atomic, Accra, Ghana
| | - Felicia Akuamoa
- Applied Radiation Biology Centre, Ghana Atomic Energy Commission, P. O. Box AE 1, Atomic, Accra, Ghana
| | - Vincent Kyei Baffour
- Toxicology Unit, Department of Chemistry, Council for Scientific and Industrial Research- Food Research Institute, P.O. Box M20, Accra, Ghana
| | - Huseini Wiisibie Alidu
- Department of Medical Laboratory Sciences, School of Allied Health Sciences, University of Health and Allied Sciences, PMB 31, Ho, Ghana
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Sensitivity enhancement for mycotoxin determination by optical waveguide lightmode spectroscopy using gold nanoparticles of different size and origin. Food Chem 2018; 267:10-14. [DOI: 10.1016/j.foodchem.2018.04.089] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Revised: 03/31/2018] [Accepted: 04/21/2018] [Indexed: 12/20/2022]
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Intanoo M, Kongkeitkajorn MB, Pattarajinda V, Bernard JK, Callaway TR, Suriyasathaporn W, Phasuk Y. Isolation and screening of aflatoxin-detoxifying yeast and bacteria from ruminal fluids to reduce aflatoxin B 1 contamination in dairy cattle feed. J Appl Microbiol 2018; 125:1603-1613. [PMID: 30074672 DOI: 10.1111/jam.14060] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 07/24/2018] [Accepted: 07/26/2018] [Indexed: 12/01/2022]
Abstract
AIMS To obtain yeast and bacteria from ruminal fluids that possess aflatoxin B1 (AFB1 ) detoxifying ability for use in animal feed. METHODS AND RESULTS Sources of isolation were ruminal fluids of three nonfistulated dairy cows, fed diets containing cassava pulp, rice straw or distillery yeast sludge. The isolation was carried out to screen for the isolates that were active in both anaerobic and aerobic conditions. Three yeast and three bacteria isolates were selected. Up to 85% of AFB1 was detoxified by yeast isolates and up to 60% AFB1 reduction was evident by bacteria isolates. Two yeast isolates were identified as Kluyveromyces marxianus and one isolate as Pichia kudriavzevii. The three bacteria isolates were identified as Enterococcus faecium, Corynebacterium phoceense and C. vitaeruminis. All strains showed high biomass production when cultivated in medium with 80 g l-1 glucose. CONCLUSIONS The isolated yeast and bacteria with AFB1 detoxifying ability showed a good potential to be applied as an aflatoxin-detoxifying agent to ingredients used to feed dairy cattle. SIGNIFICANCE AND IMPACT OF THE STUDY The abilities of isolates to survive and be active in anaerobic and aerobic conditions rendered them to be active in cattle's rumen. Their biomass could be produced in bulk and used as feed supplement for aflatoxin detoxification in dairy cattle.
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Affiliation(s)
- M Intanoo
- Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
- Graduate School, Khon Kaen University, Khon Kaen, Thailand
| | - M B Kongkeitkajorn
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen, Thailand
- Fermentation Research Center for Value Added Agricultural Products, Faculty of Technology, Khon Kaen University, Khon Kaen, Thailand
| | - V Pattarajinda
- Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
| | - J K Bernard
- Department of Animal and Dairy Science, College of Agricultural and Environmental Science, The University of Georgia, Athens, GA, USA
| | - T R Callaway
- Department of Animal and Dairy Science, College of Agricultural and Environmental Science, The University of Georgia, Athens, GA, USA
| | - W Suriyasathaporn
- Department of Feed Animal Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Y Phasuk
- Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand
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Nurtjahja K, Dharmaputra OS, Rahayu WP, Syarief R. Gamma irradiation of Aspergillus flavus strains associated with Indonesian nutmeg ( Myristica fragrans). Food Sci Biotechnol 2017; 26:1755-1761. [PMID: 30263715 PMCID: PMC6049705 DOI: 10.1007/s10068-017-0216-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 06/26/2017] [Accepted: 07/31/2017] [Indexed: 10/18/2022] Open
Abstract
The aims of this work were to investigate the effects of gamma irradiation on population, viability and aflatoxin B1 production of Aspergillus flavus strains isolated from nutmeg kernels. Thirteen strains of A. flavus were isolated and cultured in potato dextrose agar. Conidia were harvested, air-dried, and irradiated 0, 5, or 10 kGy with gamma rays using a Cobalt-60 source. Toxigenicity were determined using a coconut agar medium and thin layer chromatography. Genomes of strains were extracted from mycelia. Four sets of primers, regulatory (aflR) and structural genes (nor-1, ver-1, omt-1) were used to confirm the presence of the genes. Our results indicate that total fungal populations decreased significantly (P < 0.05) with increasing irradiation dose. However, doses of 5 and 10 kGy were insufficient to completely eliminate the viability of some A. flavus strains. Irradiation did not change toxigenicity and triggered surviving toxigenic strains to produce aflatoxin B1.
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Affiliation(s)
- Kiki Nurtjahja
- Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Jalan Agatis, Bogor, 16680 Indonesia
- Department of Biology, Faculty of Mathematics and Natural Sciences, Sumatera Utara University, Jalan Bioteknologi no. 1, Medan, 20155 Indonesia
| | - Okky Setyawati Dharmaputra
- Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Jalan Agatis, Bogor, 16680 Indonesia
- SEAMEO BIOTROP, Jalan Raya Tajur km 6, Bogor, 16134 Indonesia
| | - Winiati P. Rahayu
- Department of Food Science and Technology, Faculty of Agricultural Technology, Bogor Agricultural University, PO Box 220, Bogor, 16680 Indonesia
- SEAFAST Center, Bogor Agricultural University, Jalan Ulin No. 1, Bogor, 16680 Indonesia
| | - Rizal Syarief
- Department of Food Science and Technology, Faculty of Agricultural Technology, Bogor Agricultural University, PO Box 220, Bogor, 16680 Indonesia
- SEAFAST Center, Bogor Agricultural University, Jalan Ulin No. 1, Bogor, 16680 Indonesia
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Seetha A, Munthali W, Msere HW, Swai E, Muzanila Y, Sichone E, Tsusaka TW, Rathore A, Okori P. Occurrence of aflatoxins and its management in diverse cropping systems of central Tanzania. Mycotoxin Res 2017; 33:323-331. [PMID: 28785910 PMCID: PMC5644708 DOI: 10.1007/s12550-017-0286-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 07/05/2017] [Accepted: 07/07/2017] [Indexed: 11/29/2022]
Abstract
The staple crops, maize, sorghum, bambara nut, groundnut, and sunflower common in semi-arid agro-pastoral farming systems of central Tanzania are prone to aflatoxin contamination. Consumption of such crop produce, contaminated with high levels of aflatoxin B1 (AFB1), affects growth and health. In this paper, aflatoxin contamination in freshly harvested and stored crop produce from central Tanzania was examined, including the efficacy of aflatoxin mitigation technologies on grain/kernal quality. A total of 312 farmers were recruited, trained on aflatoxin mitigation technologies, and allowed to deploy the technologies for 2 years. After 2 years, 188 of the 312 farmers were tracked to determine whether they had adopted and complied with the mitigation practices. Aflatoxigenic Aspergillus flavus and aflatoxin B1 contamination in freshly harvested and stored grains/kernels were assessed. A. flavus frequency and aflatoxin production by fungi were assayed by examining culture characteristics and thin-layer chromatography respectively. AFB1 was assayed by enzyme-linked immunosorbent assay. The average aflatoxin contamination in freshly harvested samples was 18.8 μg/kg, which is above the acceptable standard of 10 μg/kg. Contamination increased during storage to an average of 57.2 μg/kg, indicating a high exposure risk. Grains and oilseeds from maize, sorghum, and sunflower produced in aboveground reproductive structures had relatively low aflatoxin contamination compared to those produced in geocarpic structures of groundnut and bambara nut. Farmers who adopted recommended post-harvest management practices had considerably lower aflatoxin contamination in their stored kernels/grains. Furthermore, the effects of these factors were quantified by multivariate statistical analyses. Training and behavioral changes by farmers in their post-harvest practice minimize aflatoxin contamination and improve food safety. Moreover, if non-trained farmers receive mitigation training, aflatoxin concentration is predicted to decrease by 28.9 μg/kg on average.
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Affiliation(s)
- Anitha Seetha
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi
| | - Wills Munthali
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi
| | - Harry W Msere
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi
| | - Elirehema Swai
- Agricultural Research Institute, Hombolo (ARI-Hombolo), Central Zone Crop Research, P.O.BOX 299, Dodoma, Tanzania
| | - Yasinta Muzanila
- Sokoine University of Agriculture (SUA), P.O Box 3000, Chuo Kikuu, Morogoro, Tanzania
| | - Ethel Sichone
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi
| | - Takuji W Tsusaka
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi
| | - Abhishek Rathore
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, 502 324, India
| | - Patrick Okori
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), P.O. Box 1096, Lilongwe, Malawi.
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