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. The most critical factor in the fermentation was initial substrate moisture content; wheat tempered at 30 to 31% moisture produced the highest yields. Other variables tested were agitation and aeration rates, initial static culture time, and inoculum types and volumes.