Fig. 1.

3-D response surface curves of the L-Met titer as a function of combinational effects of multiple variables. (a), glucose and yeast extract; (b), glucose and KH₂PO₄; (c), glucose and MgSO₄.7H₂O; (d), yeast extract and KH₂PO₄; (e), yeast extract and MgSO₄.7H₂O; (f), KH₂PO₄ and MgSO₄.7H₂O (f)