표면반응방법을 이용한 Beijerinckia indica L3에 의한 PS-7 생산 최적화

Abstract

The production of heteropolysaccharide-7 (PS-7) by Beijerinckia indica (B. indica L3) was evaluated in shaker flask culture. The medium optimization was studied using response surface methodology (RSM). A five-level three-factor central composite design was employed to determine the maximum PS-7 yield at optimum levels for whey lactose, glucose and ammonium nitrate contents. The validity of the model could be determined by the regression coefficient, R2. The values of R2 were 0.72, 0.64 and 0.85 in PS-7, DCW and viscosity, respectively. The optimal medium combinations of whey lactose, glucose and ammonium nitrate concentrations on the PS-7 production were whey lactose (2%), glucose (1%) and ammonium nitrate 5 mM, respectively. The result indicated that PS-7 production was affected significantly by the addition of glucose to whey lactose based on medium and C/N ratio.