Aug 27, 2013

Influence of temperature and substrate conditions on the omt-1 gene expression of Aspergillus parasiticus in relation to its aflatoxin production

International Journal of Food Microbiology
Daniel Lozano-OjalvoMar Rodríguez

Abstract

Most strains of Aspergillus parasiticus are able to produce high concentrations of aflatoxin (AF) B1 and G1 which are among the most potent mutagenic, teratogenic, and carcinogenic mycotoxins. Molecular studies in relation to activity of secondary metabolite gene clusters are crucial to improving food safety. In the present work, reverse transcriptase quantitative PCR (RT-qPCR) was used to monitor the influence of temperature, substrates containing nitrogen and incubation time on the omt-1 gene expression in A. parasiticus. Phenotypic AFB1 and G1 production was also evaluated by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The results demonstrated that temperature (25°C and 30°C) influenced relative expression of omt-1 gene throughout the time (maximum at 25°C) while substrate composition was not affected by it. However, when effect of temperature and substrate was analyzed at each incubation time, significant effects were found. Optimal conditions for biosynthesis of AFB1 and AFG1 were similar, and they were related to changes in temperature and sodium nitrate. The highest AFB1 and G1 production levels were found at 25°C. However, lower AFB1 and G1 values were obtained when A. parasiticus grew on the sub...Continue Reading

  • References38
  • Citations6

Mentioned in this Paper

Real-Time Polymerase Chain Reaction
Gene Expression Regulation, Bacterial
Tryptophan
LACE1 gene
Deoxyribonuclease I
Cacao Plant
Toxin
Aspergillus parasiticus
Candidate Disease Gene
Aflatoxins

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