The optimized fermentation protocol of 5P12-RANTES producer strain Clone 17 at the 19 L scale, generated 419 g/L wet weight of cells and 1.60 g/L 5P12-RANTES in a total of 10.9 L culture supernatant. Two 150 L scale runs were performed, a shakedown run and a cGMP run. The shakedown run generated 315 g/L wet weight of cells providing 0.91 g/L 5P12-RANTES in a total of 91.8 L culture supernatant, and the cGMP run generated 218 g/L wet weight of cells, providing and 0.82 g/L 5P12-RANTES in a total of 100.4 L culture supernatant. The lower yields of wet cell weight and volumetric productivity of 5P12-RANTES compared to the 19 L scale fermentation are due adoption of an induction fermentation time of 72 h rather than 96 h. This change was introduced because significant levels of degradation products began to accumulate after 72 h under the fermentation conditions used at the 150 L scale.