Abstract
Background: Whey as the sewage of dairy factories with a large amount of BOD (Biochemical oxygen demand 5000 PPM) is a dangerous environmental pollutant. This important Source of lactose (4-5% Lactose) is a useful substrate for producing a large kind of useful products.
Method: Single cel1 protein (SCP) is one of these products with a large cost of nutrition and comparable with other proteins. Now it is a nutrient regulator for herbivorous animal and birds.
Results: In this research the microbial strain was chosen from a lot of microorganisms in whey. The criterions of election were the weight of dried Biomass, rate of lactose reduction in whey, the rate of microbial growth and the reduction of chemical oxygen demand (COD).
Conclusions: The elected microorganism was yeast. The optimum conditions of fermentation were, 31 oc, pH=8.3, agitated at 800 rpm and aeration of 2VVm. After 25 hours fermentation was terminated and centrifugation of broth gave 8.8 g/l Biomass.