Significance of yeasts in the fermentation of maize for ogi production

Saccharomyces cerevisiae, Candida krusei, C. tropicalis, Geotrichum candidum, G. fermentans and Rhodotorula graminis were isolated during the fermentation of maize for ogi production. All the isolates except Geotrichum fermentans and Rhodotorula graminis were able to degrade phytate. All the yeasts strains exhibited lipase and esterase activities. Only S. cerevisiae (2.60%) and C. krusei (7.41%) exhibited amylase activities. Candida sp. produced wider zone of inhibition than the other yeasts strains tested during lipase activity while S. cerevisiae strains produced significantly wider zone of clearing as compared to the other yeasts for esterase activities. The study of inter-relationships between Lactobacillus plantarum and yeasts (C. krusei and S. cerevisiae) showed that the growth of the yeast strains were enhanced during fermentation by the presence of the lactic acid bacteria, but the growth of the L. plantarum strain was significantly enhanced especially by the C. krusei.