摘要
The production of poly(纬-glutamic acid) by Bacillus subtilis NX-2 from cane molasses and monosodium glutamate waste liquor (MGWL) was studied for the first time in this work. When batch fermentation was carried out with untreated molasses, 33.6 卤 0.37 g L鈭? PGA was obtained with a productivity of 0.46 卤 0.006 g L鈭? h鈭?. In order to minimize the substrate inhibition, fed-batch fermentation was performed with untreated or hydrolyzed molasses in 7.5 L bioreactor, giving 50.2 卤 0.53 and 51.1 卤 0.51 g L鈭? of PGA at 96 h, respectively. Further studies were carried out by using MGWL as another carbon source, resulting in a PGA concentration of 52.1 卤 0.52 g L鈭? with a productivity of 0.54 卤 0.003 g L鈭? h鈭?. These results suggest that the low-cost cane molasses and MGWL can be used for the environmental-friendly and economical production of PGA by B. subtilis NX-2.