title: Investigation the Effects of Lactobacillus acidophilus and Lactobacillus casei on aflR Gene expression in Aspergillus parasiticus by Real Time-PCR.
abstract: BACKGROUND
  The effect of probiotic bacteria (Lactobacillus acidophilus and L. casei) as safe organisms was examined on fungal growth and aflatoxin gene regulation in Aspergillus parasiticus.
  
  
  METHODS
  The fungus was cultured in presence of two different concentrations of L. acidophilus and L. casei in MRS broth medium. Mycelia dry weight is indicated as criteria to evaluate fungal growth. Besides, investigation of aflR gene expression by Real Time PCR was performed for analysis of gene regulatory effects in aflatoxin biosynthetic pathway.
  
  
  RESULTS
  Both Lactobacillus strongly inhibited fungal growth in the concentrations of 1. 5×10(2), [Formula: see text] . Expression analysis of aflatoxin genes pathway by real time PCR showed inhibitory effect of L. acidophilus and L. casei on expression of aflR gene. The gene expression revealed to be reduced at the approximate rates of 99. 7% and 98% respectively by L. acidopholus and L. casei in concentrations of [Formula: see text] and more.
  
  
  CONCLUSIONS
  L. acidophilus and L. casei may be used successfully as suitable candidates in controlling of A. parasiticus growth on food and feed as well as reducing of aflatoxin contamination.
authors.affiliation: Division of Microbiology, Dept. of Biology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Nateghi
authors.affiliation: Division of Microbiology, Dept. of Biology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Noorbakhsh
authors.affiliation: Division of Molecular Biology, Dept. of Medical Mycology & Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ensieh
authors.initials: E
authors.lastname: Lotfali
authors.affiliation: Division of Molecular Biology, Dept. of Medical Mycology & Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sassan
authors.initials: S
authors.lastname: Rezaie
keywords: Aflatoxin; Aspergillus parasiticus; Lactobacilus acidophilus; Lactobacilus casei; Real Time-PCR; aflR gene