Detoxification of cassava by Aspergillus niger B-1

The effects of fermentation of cassava by Aspergillus niger B-1 beta-glucosidase on its cyanide and protein content, and the optimal conditions for this enzyme's activity, were examined. This fermentation process reduced the cyanide content of cassava by 95% to 2 mg/kg, and increased its total protein content by 50%, thereby improving its nutritional value. A significant decrease in cyanogenic glycosides was detected after 3 days of fermentation. The optimal pH for A. niger beta-glucosidase activity on the cyanogenic glycoside linamarin was determined to be 3, the optimal temperature 55 degrees C, and its Km 0.3 mM. The findings presented here will facilitate the development of an improved method for detoxification of cassava and for enhancement of its nutritional value.