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<table style="height: 470px;" border="0" cellspacing="0" cellpadding="0" width="498" align="left"><tbody><tr><td height="470" align="left" valign="top"><p>Aflatoxins are produced as secondary metabolites by <em>A. flavus, A. parasiticus, A. nomius</em> and <em>A. tamarii</em>. The aflatoxin biosynthetic pathway involves several enzymatic steps and genes (<em>apa-2</em>, <em>ver-</em>1) that appear to be regulated by the <em>aflR</em> gene in these fungi. The aim of this work was the detection of aflatoxins by the HPLC method and the ascertainment of factors influencing their production. <em>A. parasiticus </em>CCM F-108,<em> A. parasiticus</em> CCF 141,<em> A. parasiticus </em>CCF 3137 and two isolates <em>A. flavus </em>were used. These toxigenic isolates were recovered from spice (strain 1) and wraps (strain 2). The gene for the production of aflatoxin B1 for each species of fungi was detected using an optimized PCR method. <em>Rhodotorula </em>spp.^*, <em>Lactococcus lactis </em>subsp.<em> lactis </em>CCM 1881, <em>Flavobacterium</em> spp. and fungal strain <em>Pythium oligandrum</em>^* were tested for inhibition of aflatoxins production and fungal growth.<em> </em>Having used the HPLC detection, various preservatives (propionic acid, citric acid, potassium sorbate) were tested from the viewpoint of their influence on the growth of aflatoxigenic fungi followed by the production of aflatoxins. The growth of <em>A. flavus</em> and <em>A. parasiticus</em> and aflatoxin production in Potato Dextrose Agar supplemented with propionic acid (1000-2000-3000 mg/kg), citric acid (2000-3000-4000 mg/kg) and potassium sorbate (500-800-1000 mg/kg) was tested by Agar Dilution Method. After 72 h of incubation was evaluated growth of fungi, all samples were frozen for later extraction and aflatoxins quantification by HPLC. Effect of peptone and sucrose additions were studied in yeast extract (2%) supplemented with peptone (5-10-15%) or sucrose (15%). Growth inhibition of <em>Aspergillus</em> by <em>Pythium oligandrum</em> was tested on wood surface. As shown, the highest inhibition effect on the aflatoxins production was obtained when propionic acid was applied in concentrations since 1000 mg/kg. A total inhibition of the fungi growth and aflatoxins production was observed in all samples containing peptone in the concentration range tested. Significant limitation of the growth and production of aflatoxins was also observed in the presence of other microorganisms such like <em>Pythium oligandrum</em> and<em> Rhodotorula </em>spp.</p></td></tr></tbody></table> <!--[endif] -->