Trypsin inhibitor activity in the field bean (Vicia faba L.)

In vitro evidence is presented for the presence of a heat‐labile inhibitor of trypsin in both cotyledon and testa of the field bean (Vicia faba L.). Inhibitor activity is destroyed by heating at 110°C for 40 min. The inhibitor has, in vitro, approximately one fifth of the strength of an extract of raw soyabeans.

Bioproduction and purification of rubratoxin B

Methods were developed for bioproduction and extraction of rubratoxin B from liquid cultures of Penicillium rubrum P-13 (NRRL A-11785). A maximum of 874.7 mg of toxin per liter of medium was attained in 21 days using stationary cultures of Mosseray's simplified Raulin solution enriched with 2.5% malt extract. Malt extract was required for rubratoxin production. Rubratoxin was not produced in either shake flasks or in fermentors with restricted aeration. Crystalline toxin was obtained by liquid-liquid extraction of concentrated culture medium with ethyl ether. Adhering colored impurities were removed by column chromatography and by recrystallization from acetone.

Investigation of reported aflatoxin production by fungi outside the Aspergillus flavus group

A screening study of 121 fungus isolates, representing 29 species, for aflatoxin synthesis demonstrated this property only in Aspergillus flavus and A. parasiticus. Eight of the organisms found negative were isolates reported by other investigators to produce aflatoxin. Since similar negative reports have come from several other workers, it is concluded that only the A. flavus group of Aspergillus can presently be certified as sources of these toxins. Reasons for possible false-positive findings are discussed along with precautionary measures and differential analytical procedures useful in aflatoxin screening studies.

Mycotoxin from Penicillium puberulum

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Toxins other than aflatoxins produced by Aspergillus flavus

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