[Feedstuffs contamination by Penicillium cyclopium Westling. Frequency of penicillic acid producing strains (author's transl)].

For the last six years, 246 samples of feedstuffs, suspected for animal disorder, have been subjected to mycological examination, Penicillium cyclopium was present with more than 10(3) and 10(5) propagules per gram respectively in 42% and 6% of samples. The feeds mainly concerned are, in decreasing order of P. cyclopium frequency and contamination level : barley, maïze mixed feeds (50%), the straw (41%), hays (21%) and milk replacers (10%) (table 1). The penicillic acid bioproduction by fifty strains freshly isolated from these feedstuffs is investigated on wet crushed corn (60% water). After incubation at 25 degrees C for a week, extraction by ethyl acetate and purification, quantification is done by fluorodensitometry on TLC plates after exposure to concentrated ammonia (fig. 1). Among the strains, 50% produces less than 5 ppm, 4% between 10-100 ppm, 20% (100-1 000), 20% (1 000-5 000) and 6% (5 000-10 000 ppm) (table 2). Maximal yield obtained was 8 240 mg/kg. Hypothesis of a log-normal distribution of toxigenic strength is not rejected (fig. 2). On the whole, frequency and toxic yields are higher for strains originating from cereals. One may think that only a quarter of the strains might be considered as actual potential penicillic acid producers in agricultural conditions.