Abstract :
Aflatoxins are very toxic secondary metabolites of some, Aspergilluss sp. that are produced when these fungi grow on different agricultural products under special environmental circumstances. In this study aflatoxinsB1, B2, G1 and G2 in some species of Aspergillus were investigated. These fungi included A. terreus, A. ustus, A. candidus, A. carneus, A. ostianus, A. auricomus, A. niveus, A. niger, A. fumigates, A. parasiticus, A. caespitosus, A. awamori and A. sclerotiorumthat were grown in potato dextrose broth (PDB) and aflatoxins thereof were measured using high performance liquid chromatography (HPLC) methods. Pure cultures of the aspergilli were prepared and identified to species, and then each species was cultured for 22 days in 50 ml flask containing PDB at 26 0C, 80% humidity and in darkness, conditions similar to natural habitat. Fungal exudates in the broth cultures were extracted with 10 ml chloroform, the organic solvent was evaporated and the precipitate was dissolved in 3ml methanol. After filtration through 0.2 µm milipore filter, the final solute was injected into HPLC instrument. Maximum amount of aflatoxins was secreted by A. parasiticus while aflatoxin G1 was not produced in A. terreus, A. carneus, A. fumigatus, A. niveus, A. parasiticus, A. caespitosus, A. ostianus and A. niger. As well, A. niveus, A. ostianus, A. niger and A. sclerotiorum did not produce aflatoxin G2. No aflatoxin B2 was detected in A. sclerotiorum and A. carneus and no aflatoxin B1 was detected in A. ostianus. Among the four type of aflatoxins (B1, B2, G1 and G2), B1 and G1 had respectively the maximum and minimum amount of secreted aflatoxins in A. parasiticus.
References:
Abbas KH, Cartwright DR, Xie W and Shier WT. 2006. Aflatoxin and fumonisin contamination of corn (maize, Zea mays) hybrids in Arkansas. Crop Protection 25: 1–9.
Agarwal VK and Sinclair JB. 1997. Seed treatment. pp. 423–460, In: VK Agarwal and JB Sinclair (eds). Principles of Seed Pathology. 2nd edition. Boca Raton: CRC Press.
Almasian S, Hoseini Gh, Sohani-Darban A and Malekzadegan F. 2008. Study of aflatoxin amount in corn meal. Paper Presented at: 18th National Congress of Food Industry; 15–17 October; Mashad, Iran.
Arrus K, Blank G, Abramson D, Clear R and Holley RA. 2005. Aflatoxin production by Aspergillus flavus in Brazil nuts. Journal of Stored Products Research 41: 513–527.
Barnett HL and Barry BH. 1979. Illustrated Genera of Imperfect Fungi. 4th ed. New York: APS Press. 218 p.
Chun HS, Kim HJ, Ok HE, Hwang JB and Chung DH. 2007. Determination of aflatoxin levels in nuts and their products consumed in South Korea. Food Chemistry 102: 385–391.
D’Mello JPF and MacDonald AMC. 1997. Mycotoxins. Animal Feed Science and Technology 69: 155–66.
Fardos B and Magda M. 2009. Trials towards reduction of fungal growth and aflatoxin G1 production in Arabic coffee using different additives. African Journal of Food Science 3: 68–76.
Fente CA, Ordaz JJ, Vazquez BI, Franco CM and Cepeda A. 2001. New Additive for Culture Media for Rapid Identification of Aflatoxin -Producing Aspergillus Strains .Applied and Environmental Microbiology 67: 4858–4862.
Gqaleni N, Smith EJ, Laceny J and Gettinby G. 1997. Effects of temperature, water activity, and incubation time on production of aflatoxins and cyclopiazonic acid by an isolate of Aspergillus flavus in surface agar culture. Applied and Environmental Microbiology 63: 1048–1053.
Haung Ch. 2007. Mechanism of intraspecific toxin inhibition in Aspergillus flavus. [MSc]. [Baton Rouge (Louisiana)]: Louisiana State University.
Khanafari A, Soudi H and Miraboulfathi M. 2007. Biocontrol of Apergillus flavus and aflatoxin B1 production in corn. Journal of Environmental and Health Science 4: 163–168.
Klick MA. 2002. Identification of Common Aspergillus Species. An Institute of the Royal Netherlands of Arts and Sciences, Dordrecht: Centraalbureau Voor Schimmelcultures (CBS) Publishing. 116 p.
14. Mayahi M, Jalali MR and Salamat N. 2007. Isalation of Asperigillus from fish powder, corn and soybean meal and measurement of their aflatoxin contents. Science (Shahid Chamran University) 17: 95–105.
Mehdizadeh M, Rabiei M, Moini Namin, M and Asghari Sh. 2008. Role of Asperigillus species in creating aflatoxicose. Journal of Shaeed Sdoughi University of Medical Sciences Yazd 16: 100–107
Rahimi E, Kargar AR and Zamani F. 2008. Assessment of aflatoxin B1 levels in animal feed of dairy farms in Chaharmahal & Bakhtiari. Pajouhsh & Sazandegi 79: 66–71
Reddy KRN, Reddy CS and Muralidharan K. 2009. Detection of Aspergillus spp. and aflatoxin B1 in rice in India. Food Microbiolog. 26: 27–31.
Reddy KRN, Saritha P, Reddy CS and Muralidluran K. 2009. Aflatoxin B1 producing potential of Aspergillus flavus strains isolated from stored rice grains. African Journal of Biotechnology 8: 3303–3308.
Reddy SV and Waliyar F. 2008. Properties of afltoxin and it producing fungi. [cited 2013 Jun 10]. Available from: www.aflatoxin. Info/aflatoxin.asp.
Ricordy R, Cacci E, Augusti Tocco G. 2005. Aflatoxin B1 and cell cycle perturbation. pp. 213–231, In VR Preedy and R Watson (eds). Reviews in Food and Nutrition Toxicity, 4th ed. London: CRC Press.
Rodrigues P, Venâncio A, Kozakiewicz Z and Lima N. 2009. A polyphasic approach to the identification of a flatoxigenic and non-aflatoxigenic strains of Aspergillus section Flavi isolated from Portuguese almonds. International Journal of Food Microbiology 129: 187–193.
Scherm B, Palomba M, Serra D, Marcello A and Migheli Q. 2005. Detection of transcripts of the aflatoxin genes aflD, aflO, and af lP by reverse transcription–polymerase chain reaction allows differentiation of aflatoxin-producing and non-producing isolates of Aspergillus flavus and Aspergillus parasiticus. International Journal of Food Microbiology 98: 201–210.
Tayebi J and Mirabolfathi M. 2001. Infection of some hybrid corns to B1 and B2 aflatoxin and the casual fungus in the field. Journal of Applied Entomology and Phytopathology 69: 79–84
Villa P and Markaki P. 2009. Aflatoxin B1 and ochratoxin A in breakfast cereals from Athens market: Occurrence and risk assessment. Food Control 20: 455–461.
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