Breeding of L-arginine-producing strain and optimization of fermentation conditions

摘要

A L-arginine-producing mutant Corynebacterium glutamicum ZD2009 was selected out by arginine-methylester (AE) resistance after stepwise mutagenic treatment withN-methyl-N-nitro-N-nitrosoguanidine (NTG) from Corynebacterium glutamicum DSM1412. This mutant also has good stability of descendibility of L-arginine. After investigating fermentation medium by orthogonal analysis, results showed optimal medium containing glucose 9.0%, corn steep liquor 3.0%, (NH_4)_2SO_4 6.0%, KH,PO_4 0.05%, MgSO_4~-7H,0 0.03% and calcium carbonate 2.0%, inoculum size 6%, pH 7.0, liquid volume 15 ml/100 ml. Mutant Corynebacterium glutamicum ZD2009 could accumulate L-arginine 44 g/1, on average, which increased about 41.9% more than before in this optimized medium when it was cultured at 30°C for 4 days.