Isolation and Study on the Aflatoxin Genes of Aflatoxin-producing Fungi in Paprika Samples in Chengdu

LING Li, YE Zheng-mao, WANG Su-yuan. et al

Abstract

To isolate aflatoxin-producing strains from paprika samples and to do a preliminarily study on the relationship between aflatoxin-producing ability and the genes aflR, omt-1and ver-1 Methods Fungi were isolated by traditional culture method. Potential aflatoxin-producing strains were screened by phenotypic traits and multiplex PCR. After these potential aflatoxin-producing strains cultured in the toxigenic culture medium, the levels of aflatoxin B1 (AFB1) of the cultures were tested with ELISA method. The phylogenetic tree of aflR, omt-1and ver-1 was constructed to explore the relationship between these genes and the AFB1-producing capacity. Results 17 potential aflatoxin-producing fungi were isolated. The ratio of positive toxigenic strains is 64.71%. 11 isolates were positive in AFB1 detection while existing high sequence homology with AS 3.4408, 6 isolates were negative in AFB1 detection while existing high sequence homology with Aspergillus oryzae. Conclusion Aspergillus flavusare potential candidates for aflatoxin control. Not all Aspergillus flavus have AFB1-producing capacity, AflR gene had a direct relation to AFB1-producing capacity, while ver-1 and omt-1were related to the level of AFB1 producing.

 

Keywords: Aflatoxin B1, Aspergillus flavus, Paprika, Homology analysis, AflR Omt-1 

 

Full Text:

PDF


References


Groopman JD. Wogan ON. Aflatoxin and hepatocellular carcinoma. In: Т. M. Penning. Chemical Carcinogenesis. 1st ed. New York; Humana Press,2011; 113-133.

Jiujiang Y. Current understanding on aflatoxin biosynthesis and future perspective in reducing aflatoxin contamination. Toxins,2012;4(11):1024-1057.

Amare MG, Keller NP. Molecular mechanisms of Aspergill us flavus secondary metnbolismnnd development. Fungal Genet Biol,2014;66:11-18. doi:10. 1016/j. fgb. 2014.02.008.

Liang SH, Skory CD, Linz JE. Characterization of the function of the verlA and ver-1В genes, involved in aflatoxin biosynthesis in Aspergillus parasiticus. Appl Environ Microbiol, 1996 ;62( 12) =4568-4575.

Motomura M. Chihaya N, Shinozawa T-et al. Cloning and charaeterizeation of the O-methyltranferase gene from Aspergillus parasiticus associated with the converseon of demethylsterigmatocystin to sterigmatocystin and dihydrodemethylstermatocystin to dihydrostermatocystin in aflatoxin biosynthesis. Appl Environ Microbiol, 1999;65(11) ; 4987-4995.

Yu J, Ronning CM, Wilkinson JR, et al. Gene profiling for studying the mechanism of aflatoxin biosynthesis in Aspergillus flavus and A. parasiticus. Food Addit Contam, 2007;24(10):1035-1042.

LeeJW, Roze LV, Linz JE. Evidence that a wortmannin- sensitive signal transduction pathway regulates aflatoxin biosynthesis. Mycologia,2007;99(4):562-568.

Georgianna DR, Payne GA. Genetic regulation of aflatoxin biosynthesis: from gene to genome. Fungal Genet Biol, 2009; 46(2):113-125.

Watson AJ, Fuller LJ . Jeenes DJ , et al. Homologs of aflatoxin biosynthesis genes and sequence of aflR in Aspergillus oryzae and Aspergillus sojae. Applied Environ Microbiol. 1999; 65 (1):307-310.

Machida M, Asai K, Sano M, et al. Genome sequencing and analysis of Aspergillus oryzae. Nature.2005 ;438( 7071): 1157- 61.


Refbacks

  • There are currently no refbacks.