Production of polysaccharides from Angelica sinensis by microbial fermentation

Angelica sinensis polysaccharides are important active ingredients and biological resources in traditional Chinese medicine. Properly changing the fermentation conditions of microorganisms may alter the yield of fermentation products. Based on single factor test results, three factors with great influence on the yield of Angelica sinensis polysaccharides produced by Aspergillus niger were optimized: initial pH value, fermentation time, and culture temperature. According to the box Behnken central combination principle, a response surface analysis scheme with three factors and three levels was designed, and the yields of active polysaccharide of Angelica sinensis were taken as the response value to optimize the fermentation process. The results of response surface analysis showed that under the optimized fermentation temperature of 30 °C, cultivation time of 8 days, and initial pH value of 5, the predicted yield of active polysaccharides from Angelica sinensis was 15.5%, while the actual value was 15.35%, which was 0.11% lower than the predicted value. This indicated that using response surface analysis to optimize the fermentation conditions of Angelica sinensis polysaccharides was reasonable and feasible. This method can effectively improve the biological resource utilization rate of Angelica sinensis polysaccharides.