earticle

영어

In this study, a process of removing a half volume of the culture broth and replacing it with the same volume of substituted solution after 48 h of cultivation was developed to enhance the production of heteropolysaccharide-7 (PS-7) by Beijerinckia indica HS-2001. The optimal substitution time and volume of the substituted solution were found to be 48 h after cultivation and a half of the initial volume of the culture broth. The optimal concentration of glucose in the substituted solution and inoculum size were 20.0 g/L and 5.0% (v/v). Optimal composition for the substituted solution was found to be 20.0 g/L glucose, 10.0 g/L soybean pomace, 0.1 g/L MgSO4 .7H2O, 0.9 g/L NH4NO3, and 5.0 g/L potassium phosphate, which was the same composition as the medium developed in previous study for the production of PS-7 by B. indica HS-2001. Total amount and productivity of PS-7 by B. indica HS-2001 with a substitution under optimized conditions in a 7 L bioreactor for 96 were 49.28 g and 0.51 g/h, which were 1.76 and 1.31 times higher than those without a substitution for 72 h.