Use of radiation for the improvement of fungal strains as the nutritional additive in the carbohydrate-rich root crops of Nigeria. Coordinated programme on radiation microbiology

After a short introduction describing the use of West African root plants (yams, cassava) as food and ways of increasing the protein content of this food, experiments on protein production by microbial fermentation of starches are described. Cassava starch was fermented as solid extrusions and in liquid phase with Rhizopus oligosporus wild and mutant strains (mutants obtained by irradiation with Co 60 source). The mutant strain was found to produce more proteins both on solid cassava starch extrusions and in liquid starch media. Experiments were carried out also with combinations of Rhizopus and other micro-organisms (Candida, Endomycopsis, Geotrichum, Saccharomyces) and with cassava starch supplemented with sugar cane molasses. The cyanogen glucoside content of cassava and the effect of cyanide on the protein production was also investigated