The aim of this study was to characterize the different biochemical and microbiological changes and the effect of the cassava variety during the fermentation of traditional cassava starter. Two cassava varieties, (IAC) and (Bonoua) were investigated at different fermentation times. The load of microorganisms (lactic acid bacteria, coliforms, yeast and mould, aerobic mesophilic, Bacillus) and biochemical parameters (pH, titratable acidity, total and reducing sugar) were assessed. During fermentation, progressive acidification was observed in the pulp of both cassava varieties (0.02-0.12%). The sugar consumption was observed during cassava fermentation (2.4-1.1 mg/g). Rapid growth of coliforms (total and thermotolerant) was obtained between 0 and 48 hours followed by a decrease after 48 hours. The fermentative microflora (lactic acid bacteria, yeast and mould, Bacillus) growth was recorded up to 72 hours before a drop. Contrary to the cassava variety, fermentation time has a significant influence on the evolution of biochemical and microbiological parameters.

The present investigation was conducted on sandy soil at Is mailia Agricultural Research Station during the two successive summer seasons 2014 and 2015 to study the effect of biofertilizers with nitrogen (N) and potassium (K) mineral fertilizers at different rates on yellow corn single cross 173(SC 173) yield and some crop physicochemical as well as technological parameters. Three treatments of biofertilizer: 1) rhizobacterin, 2) potassiomage, 3) microbin and control (untreated) with two N rates: 60 and 120 kg fed-1 and two K rates: 12 and 24 kg K2 O fed-1 were used. Results showed significant differences among biofertizers for all traits. Corn plants were earlier in days to 50% tasseling (DTT) and days to 50% silking (DTS) when rhizobacterin or potassiomage was applied at 120:12 N:K kg fed-1 in the two seasons. The highest grain yield was obtained when potassiomage was applied at 120:12 N:K (kg fed-1) in both seasons. Analysis of grains showed that protein content significantly increased by biofertilizer application and the highest value of protein content was recorded by potassiomage treatment at 120:12 N:K (kg fed-1). Fat content increased significantly in potassiomage and microbin treatments relative to control at different N:K rates . Germ percentage increased significantly in all biofertilzer treatments. Applying of biofertilizers increased 100 grain weight, potassiomage treatment at 120:12, N:K (kg fed -1) s howed the highest value being 29.05g. NPK levels increased by biofertilizer application. Moreover, there was a significant increase of total carotenoid in bioferilized treatments relative to control. Regarding to corn protein fractions, results indicated that albumins and globulins fractions percentage increased significantly by biofertilizer application. The highest values of albumins and globulins were observed in potassiomage treatments at all N:K (kg fed-1) rates. Results of sensory evaluation revealed that tortilla with high quality produced by biofertilizer application.