Optimization of process parameters for tacrolimus (FK 506) production by new isolate of Streptomyces sp. using response surface methodology (RSM)

An isolate of Streptomyces was found to be positive for the production of tacrolimus. HPLC analysis on C-18 column at flow rate of 0.5 ml/min samples gave retention time of 4.26 min as standard. Soyoil, soybean meal and L-lysine were selected as significant model factors by plackett burman (PB) design. Response surface methodology was employed to optimize these factors. A second-order quadratic model and response surface method showed that the optimum conditions (soyoil: 23.40 gm/L; soybean meal gm/L: 18.40; L-lysine: 1.00 gm/L) resulted in the improvement of tacrolimus production (235.5± 1.96 mg/L) as compared to the initial level (135.6± 2.56 mg/L). It was about 1.73 fold increase as compared with that using the original medium. The value predicted by the quadratic model was (236.3 mg/L). Analysis of variance showed a high coefficient of determination (R2) value of 0.9978 ensuring a satisfactory adjustment of the quadratic model with the experimental data. This is first report on tacrolimus production using plackett burman design and response surface methodology in submerged fermentation.