OPTIMIZATION OF CULTIVATION MEDIUM COMPOSITION OF AN L-LYSINE PRODUCING MUTANT - THE USE OF RESPONSE-SURFACE METHODOLOGY

The response surface methodology and experimental central composite de sign was applied to search for optimal medium composition for L-lysine bioprocess optimization. The factors selected for test were glucose, ammonium sulphate, yeast extract, MnCl2 and biotin. To study the effec t of these factors, a second-order polynominal model was used to estim ate the coefficient of regression. The path of the steepest ascent app lied based on the model proved effective in searching for the optimal levels of the chosen medium nutrients. The optimum component compositi on was found to be 11.9, 3.5, 0.54, 5.88 and 58.6, respectively. Compl ementary experiments within this optimum gave a yield of 56.2 g/dm3 L- lysine.