[Culture of Aspergillus parasiticus in apple juice. I. The influence of sodium benzoate and potassium sorbate on fungal growth and aflatoxin biosynthesis]. / Kultur von Aspergillus parasiticus im Apfelsaft. I. Einfluss von Natriumbenzoat und Kaliumsorbat auf Pilzwachstum und Aflatoxin-Biosynthese.

Sodium benzoate or potassium sorbate (100, 200, 300 and 400 mg/l) were added to cultures of Aspergillus parasiticus NRRL 2999 on apple juice (from syrup) and incubated quiescently at 25 degrees C for 3, 6, 9, 12 or 15 days. The cultures were analyzed for pH, mycelial dry weight and accumulation of aflatoxin B1 and G1. The initial pH of 2.5 remained constant in all instances throughout the incubation period. Sodium benzoate, at all concentrations, suppressed fungal growth and stimulated the biosynthesis of G1, whereas little influence was exerted upon the accumulation of B1. Potassium sorbate stimulated fungal growth at 100 mg/l, while at all concentrations it considerably inhibited toxin production (no detectable amounts of B1 and 3 to 5 times less G1 than in controls). The concentration of G1 surpassed that of B1 without exception.

[Culture of Aspergillus parasiticus in apple juice. II. The effect of butylhydroxyanisole (BHA) and butylhydroxytoluol (BHT) on fungal growth and aflatoxin biosynthesis]. / Kultur von Aspergillus parasiticus im Apfelsaft. II. Einfluss von Butylhydroxyanisol (BHA) und Butylhydroxytoluol (BHT) auf Pilzwachstum und Aflatoxin-Biosynthese.

Aspergillus parasiticus (NRRL 2999) was incubated in apple juice (from syrup), quiescently at 25 degrees C for up to 15 days in the presence of butylated hydroxyanisole (BHA) or butylated hydroxytoluene (BHT) at concentrations of 100, 200, 300, or 400 mg/l. Mycelial dry weight, pH and concentration of aflatoxin B1 and G1 were measured every 3 days with the initial pH of 2.5 remaining unchanged in all samples. BHA suppressed fungal growth and toxin accumulation during the observed incubation period. However, a concentration-dependent growth delay and earlier peaks of toxin accumulation suggested environmental adaptation of the mould. BHT (from 200 mg/l onwards), led to growth inhibition by about 25% (solubility limit of BHT lies between 200 and 300 mg/l), and at a concentration of 200 mg/l, it led to a reduction of toxin accumulation by approximately 45%. At 100 mg/l, however, BHT stimulated aflatoxin production (1.90 times more G1 and 6.65 times more B1 than in the controls). At all tested concentrations of BHA or BHT, as well as in the controls, the accumulation of aflatoxin G1, without exception, surpassed that of B1.