Background: Optimization of nutrient feeding was developed to improve the growth of Bacillus subtilis in fed batch fermentation to increase the production of Jiean-peptide (JAA¹). 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 5l fermentor.

Results: 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.

Conclusion: The results of this work improve the present production of JAA and may be adopted for other objective products' production.