Optimization of nutrient feeding was developed to improve the growth of Bacillus subtilis
batch fermentation to increase the production of jiean-peptide (JAA). A central composite design (CCD) was
used to obtain a model describing the relationship between glucose, total nitrogen, and the maximum cell dry
weight in the culture broth with fed batch fermentation in a 5 L fermentor.
The results were analyzed using response surface methodology (RSM), and the optimized values of
glucose and total nitrogen concentration were 30.70 g/L and 1.68 g/L in the culture, respectively. The highest
cell dry weight was improved to 77.50 g/L in fed batch fermentation, which is 280% higher than the batch
fermentation concentration (20.37 g/L). This led to a 44% increase of JAA production in fed batch fermentation
as compared to the production of batch fermentation.
The results of this work improve the present production of JAA and may be adopted for other
objective products' production.