Plackett-burman design for screening of fermentation process parameters and their effects on l-methionine production

In the present study, economical fermentation medium process was developed to achieve the maximum production of L-methionine by Corynebacterium glutamicum through screening of different nutritional and physical parameters by Plackett-Burman design. A total of eleven process variables such as plantain as carbon source, groundnut as nitrogen source, CaCO₃, K₂HPO₄, KH₂PO₄, biotin, MgSO₄.7HO², inoculum size, agitation speed, volume ratio of medium/fermenter and pH were used for screening experiments. The PBD model results suggested that seven variables namely plantain as carbon source, groundnut as nitrogen source, CaCO₃, MgSO₄.7H₂O and KH₂PO₄ had shown a significant effect on L-methionine production, while remaining six variables didn't show a much effect on Lmethionine production. The R² value (0.99) of analysis of variance (ANOVA) recommended that the model used for response prediction is significant (p<0.05). In comparison with the unoptimized medium, 24% higher L-methionine production was obtained from the optimized medium and L-methionine production was found to be 5.6 g/l.