Recombinant Escherichia coli strain C600/pBV-TRAIL (encoding for 114-281 amino acids of TRAIL's soluble fragment) produced a recombinant human tumor necrosis factor-related apoptosis-inducing ligand (Apo2L/TRAIL). Using a combined strategy of exponential feeding and pH-stat feeding, high concentrations of biomass (65 g dry wt l(-1)) and active soluble TRAIL (1.4 g l(-1)) were obtained within 30 h. The accumulation of acetate, which usually occurs during the process of high-density culture of Escherichia coli and especially in the induction stage of protein synthesis, was avoided.