Improvement in the production of L-Lysne by ENU treated Chemical mutagenesis of ddh gene recombinant strain of Corynebacterium glutamicum MTCC25069

Auxotrophic mutant formed from ddh gene recombinant MTCC25069with blocked homoserine dehydrogenase showed an increased yield of L Lysine of 24.89 g/l from normal ddh gene recombinant MTCC25069strain which had a yield of 20.66 g/l of L Lysine. The maximum yield of Llysine for the auxotrophic mutant is attained at 7.5 pH, 300C of temperature and an incubation time of 96 hrs. The Auxotrophic mutant of ddh recombinant C. glutamicum showed nearly 6.52 g/l more amount of l lysine than Auxotrophic mutant of wild type with 18.57 g/l of L Lysine. The Chemical mutagen ENU caused mutation in the Homoserine serine dehydrogenase enzyme diverted the Aspartyl â semialdehyde to bind with 2, 3Dihydrodipicolinate synthase to participate in the L Lysine synthesis through 2, 3 meso-Diaminopimelate (Meso-Dap). Being a recombinant for diaminopimelate dehydrogenase (ddh) the auxotrophic mutant for the homoserine dehydrogenase follows the ddh pathway by overexpression of ddh by deviating the Acetyltransferase and Succinyl transferase is the reason for the high yield of L Lysine production.