Page 278 - Demo

282 PROCEEDINGS OF INTERNATIONAL SCIENTIFIC CONFERENCE ON APPLIED BIOTECHNOLOGYAll Previous studies have shown that K2HPO4 has a significant positive effect on MK-7 production yield when using Bacillus subtilis natto [7,8]. In this experiment, the effect of K2HPO4 concentration (ranging from 0.5 to 10 g/L) on vitamin K2 production by strain BST2 was investigated. Figure 1 shows that the fermentation medium supplemented with 0.5 g/L K2HPO4 produced the highest yield of vitamin K2, reaching 1309.7 %u00b5g/L. However, at higher K2HPO4 concentrations, vitamin K2 production significantly declined, reaching 717.8 %u00b5g/L at 10 g/L K2HPO4.Figure 1. Effect of K2HPO4 concentration on vitamin K2 production by strain BST2Figure 2. The vitamin K2 band on TLC plate under UV light