Wild rice as fermentation substrate for mycotoxin production.

Many cereal grains have been studied for their suitability as substrates for the fermentative production of mycotoxins. However, except for aflatoxin, wild rice has not been investigated. Hence, five mold cultures known to produce the mycotoxins ochratoxin-A, penicillic acid, patulin, vomitoxin, and zearalenone were grown on wild rice under varying conditions of moisture and temperature to determine whether this grain would serve as a suitable substrate for toxin production.

Penicillic acid production in submerged culture.

Twenty known penicillic acid (PA)-producing Aspergillus and Penicillium cultures were grown under various conditions in shaken flasks to determine the highest yielding strains and their requirements for maximum toxin production. Abilities of the cultures to utilize eight different carbon sources in Raulin-Thom medium for mycotoxin synthesis were determined at four different incubation temperatures: 15, 20, 25, and 28 degrees C. Of the 20 cultures, P.

Solid-substrate fermentor for ochratoxin A production.

A laboratory-scale fermentor designed for solid-substrate fermentation was constructed and tested. Its capacity to produce ochratoxin under varied conditions was determined with wheat as substrate. Ochratoxin yields of 2,000 to 2,500 mug/g of wheat were regularly obtained, and occasionally yields as high as 4,000 mug/g were obtained.