title: Application of statistically based experimental designs for the optimization of exo-polysaccharide production by Cordyceps militaris NG3.
abstract: Statistically based experimental designs were applied to the optimization of medium composition for exo-polysaccharide production by Cordyceps militaris NG3 in shake-flask cultures. First, the Plackett-Burman design was used to search for the main factors on mycelia and exo-polysaccharide production. Among these variables, sucrose and corn steep powder were found to be two significant factors and had positive effects on mycelial yield (with confidence level >80%) and exo-polysaccharide production (with confidence level >90%). Subsequently, to study the mutual interactions between variables, the effects of the two main factors on exo-polysaccharide production were further investigated using a central composite design. The optimal composition was found to be 1.03 g/l corn steep powder, 2.95 g/l sucrose, 0.1 g/l K(2)HPO(4), 0.5 g/l MgSO(4) x 5H(2)O and 0.1 g/l KNO(3) for the enhanced production of the exo-polysaccharide, which was 2.604 g/l in shake-flask cultures. Under optimal culture conditions, the maximum exo-polysaccharide concentration in a 5 l stirred-tank bioreactor was 3.8 g/l.
authors.affiliation: Department of Biotechnology, Taegu University, Kyungsan, Kyungbuk 712-714, South Korea.
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Xu
authors.forename: Sang-Woo
authors.initials: SW
authors.lastname: Kim
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Yun
mesh_terms: D019149:Bioreactors; D002478:Cells, Cultured; D032661:Cordyceps / Q000254:growth & development / Q000378:metabolism*; D008954:Models, Biological; D015233:Models, Statistical; D025282:Mycelium / Q000254:growth & development; D011134:Polysaccharides / Q000096:biosynthesis*; D011786:Quality Control; D012107:Research Design; D012680:Sensitivity and Specificity
chemical_list: D011134:Polysaccharides