Selection of Basic Medium and Culture Condition Using Fractional Factorial and Central Composite Design for Cell Growth and Production of Phycobiliprotein by Synechocystis PCC6701

초록

BG-11 is a universal medium for cyanobacteria cultivation. However, BG-11 is normally a me-dium of maintaining cell condition for genetic engineering. So, selection of basic medium for cell culture and production of phycobiliprotein was carried out in illuminated shaking incubator with various media for freshwater condition. The growth rates for various media were 0.21/day in BG-11, 0.57/day in medium for Scenedesmus sp. and 0.18-0.32/day in the other tested media for 11 days. Medium for Scenedesmus sp. maintain neutrality because of high phosphate content. Medium for Scenedesmus sp. was selected as the basis and optimized by fractional factorial design and central composite. Fractional factorial design had seven factors:KNO3, NaNO3, NaH2PO4, Na2HPO4, Ca(NO3)2, FeNaEDTA, each one at two levels. From the result of frac-tional factorial design, the significant factors were identified as nitrate and phosphate. Central composite design was applied by four variables as nitrate, phosphate, pH, light intensity at five levels. Parameters such as dry cell weight, phycoerythrin and phycobiliprotein were used to se-lect the optimum value of the four variables. The cell growth and phycobiliprotein were correlated to nitrate and light intensity and to pH and light intensity, respectively. The optimum values of nitrate, phosphate and light intensity were 0.51g/L, 0.17g/L and 10 mmol/m2/s for cell growth and phycobiliprotein production.