Fermented dairy such as yogurt, have gained popularity due to their potential health benefits. These products contain probiotic bacteria, including Bifidobacterium species, which are known for their positive effects on gut health. Overall, this study aimed to isolate and molecularly characterize different isolates of probiotic bacteria and to enhance their fermentation time by mutagenesis.  The local market and Faculty of Agriculture farm in Assiut University were used to collect different samples such as fermented dairy products, milk, and soybeans. These various sources were used to isolate different bacterial isolates.
Thirty-three different bacterial isolates were collected and identified biochemically, morphologically, and molecularly using PCR specific primers. Morphological, biochemical, and molecular tests showed that 13 isolates were identified as Bifidobacteria and further species identification were also done. Milk fermentation time was also tested for all the isolates. The fermentation time measurement showed that isolate no.11 had the lowest curd time (13 to 14 h). After mutagenesis, the mutant obtained from isolate No.11 recorded enhanced fermentation time of only 4 h.