Abstract
The production of vitamin B12 and folate under solid state fermentation was investigated by using different mutants of klebsiella penumonia. The results showed that the isolate no ( EM33TE) produce the maximum B12 and folate yields ( 77.45 and 88.22 ug/ml) respectively. The supplementation of the fermentation medium by different carbon sources (glucose, fructose, mannose, sucrose, maltose, lactose ,starch and dextrin) indicated that the best carbon source was glucose and the maximum B12 yield (356.9ug/ml) was obtained by the sequential addition of glucose(10g ) to the fermentation medium . PCR studies revealed that clear differences at bands number and size between the original strain and its mutants using RAPD analysis by three different random primers, these differences in RAPD profiles confirmed the evidence of genetic variations of mutants and K.pneumonia genome after EMS-mutagenesis