Optimized Amino Acid-Enhanced Medium for Efficient L-Asparaginase II Production in E. coli: From Shake Flask to Bioreactor

L-asparaginase (L-ASNase) is a key enzyme in the treatment of leukemia and lymphoma, with high demand in cancer therapies. Advances in recombinant protein production have improved yields and reduced costs, enabling large-scale production. However, optimizing culture conditions remains crucial for maximizing production. This study focused on optimizing the production of double mutant L-ASNase expressed in Escherichia coli BL21 (DE3) by supplementing media with amino acids. Five amino acids were evaluated at a shake flask scale using the design of experiments, with arginine and aspartate showing the most positive effects. Under optimized conditions (14.5 mM arginine, 12.7 mM aspartate, and 0 mM cysteine), the activity model reached 12,513 U L−1, experimentally validated at 10,089 U L−1. The maximum specific cell growth rate was µx,max = 0.74 h−1, with substrate–biomass conversion factor Yx/s = 1.16 g/g and cell–product conversion factor Yp/x = 13,891 U/gcell. Amino acid supplementation resulted in a ten-fold increase in L-ASNase activity. Finally, at the bioreactor scale, adding amino acids and the inducer at the end of the exponential phase increased activity by 135% compared to conventional MD, demonstrating its potential for industrial-scale production.