Factors affecting the fermentative production of L-valine were studied and optimal conditions were determined in the shake flask production by Aerobacter aerogenes NISR-B-801.
Optimal C/N-ratio, 100:7.8 (at 10% glucose), and adequate aeration, Kd. about 6.0×10-6 [gram-mole of oxygen per atm. min. cc of broth], were found to be the most important factors to bring about L-Valine fermentation. Chemical ingredients of media, especially trace elements (e.g., Ni, Mn, Mo) as well as bulk elements (phosphorus, Mg, K) have also remarkable influences on valine formation. The most efficient fermentation was performed with optimum inocula, 4-5 per cent(v/v) of media, under optimal pH 6.2-5.4.
The high yields of L-valine, about 20 per cent conversion of glucose, were obtained under the conditions studied.