[Isolation and Study on the Aflatoxin Genes of Aflatoxin-producing Fungi in Paprika Samples in Chengdu]
Objective:
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-1 and 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 B, (AFB1) of the cultures were tested with ELISA method. The phylogenetic tree of aflR, omt-1 and 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 flavus are 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-1 were related to the level of AFB1 producing.
Insights
This study isolated potential aflatoxin-producing fungi from paprika, finding that while not all Aspergillus flavus strains produce aflatoxin B1 (AFB1), the aflR gene directly correlates with AFB1 production capacity, and ver-1 and omt-1 influence the production level.
Area of Science:
- Food Microbiology
- Mycology
- Molecular Biology
Background:
- Aflatoxins are toxic secondary metabolites produced by certain Aspergillus species, posing significant health risks.
- Paprika can be a potential source of aflatoxin contamination, necessitating identification of producing strains.
- Understanding the genetic basis of aflatoxin production is crucial for control strategies.
Purpose of the Study:
- To isolate and identify aflatoxin-producing fungal strains from paprika.
- To investigate the relationship between aflatoxin B1 (AFB1) production and the presence/expression of aflR, omt-1, and ver-1 genes.
- To assess the potential of Aspergillus flavus for aflatoxin control.
Main Methods:
- Fungal isolation using traditional culture methods.
- Screening of potential aflatoxin producers via phenotypic traits and multiplex PCR.
- Quantification of AFB1 levels using ELISA.
- Phylogenetic analysis of aflR, omt-1, and ver-1 genes.
Main Results:
- 17 potential aflatoxin-producing fungi were isolated, with a 64.71% toxigenic strain ratio.
- 11 isolates tested positive for AFB1, showing homology with Aspergillus flavus.
- 6 isolates tested negative for AFB1, despite homology with Aspergillus oryzae.
Conclusions:
- Aspergillus flavus strains are identified as potential candidates for aflatoxin management.
- Not all Aspergillus flavus strains possess AFB1-producing capabilities.
- The aflR gene shows a direct correlation with AFB1 production, while ver-1 and omt-1 influence the level of AFB1 produced.
More Related Videos
09:44RNAi-mediated Control of Aflatoxins in Peanut: Method to Analyze Mycotoxin Production and Transgene Expression in the Peanut/Aspergillus Pathosystem
Published on: December 21, 2015
10:24Author Spotlight: Quantification of Aflatoxins and Phytoalexins in Peanut Seeds to Identify Genetic Resistance Against Aspergillus
Published on: April 19, 2024