Statistical optimization of medium components for improved synthesis of riboflavin by Eremothecium ashbyii

Statistical designs were used to determine optimum levels of medium nutrien ts for riboflavin production in shake flask fermentation. The medium compon ents considered include molasses, sesame seed cake (SSC), yeast extract, KH 2PO4, MgSO4 . 7H(2)O, NaCl and Tween-80. Information about the effects of d ifferent medium components on riboflavin production were investigated by us ing the Plackett-Burman experimental design. MgSO4 . 7H(2)O and NaCl were f ound to significantly influence the riboflavin production (confidence level s above 70%). For obtaining the mutual interaction between the variables re quired, for achieving the optimal concentrations, a 2(2)-factorial central composite design was employed. The optimal concentrations for the enhanced production of riboflavin were (g/l): molasses = 50.0 (glucose equivalents); SSC = 50.0; yeast extract = 2.0; KH2PO4 = 2.0; MgSO4. 7H(2)O = 0.117 and N aCl = 1.13.