l-asparaginase II (ASNase) is the biopharmaceutical of choice for the treatment of acute lymphoblastic leukaemia. In this study, E. coli BL21 (DE3) transformed with the pET15b + asnB vector which expresses recombinant ASNase was used as a source to obtain this enzyme. The ideal conditions to produce ASNase would be a high level of secretion into the extracellular medium, which depends not only on the application of molecular biology techniques but also on the development of a strategy to modify cell permeability such as the addition of substances to the culture medium that stimulate destabilisation of structural components of the cell. Thus, the growth of E. coli BL21 (DE3) in modified Luria–Bertani broth, supplemented with 0.8% (w/v) glycine and 6% (v/v) n-dodecane, increased the total yield of ASNase by about 50% (15,108 IU L⁻¹) and resulted in a 16-fold increase in extracellular enzymatic productivity (484 IU L⁻¹ h⁻¹), compared to production using the same medium without addition of these substances. Most of the enzyme (89%) was secreted into the culture medium 24 h after the induction step. This proposed approach presents a simple strategy to increase extracellular production of ASNase in E. coli.

L-天冬酰胺酶 II ( ASNase ) 是治疗急性淋巴细胞白血病的首选生物药物。本研究以表达重组ASNase的pET15b+asnB载体转化的大肠杆菌BL21(DE3)为来源获得该酶。生产 ASNase 的理想条件是高水平分泌到细胞外培养基中，这不仅取决于分子生物学技术的应用，还取决于开发改变细胞通透性的策略，例如向培养物中添加物质刺激细胞结构成分不稳定的培养基。因此，大肠杆菌的生长BL21 (DE3) 在改良 Luria-Bertani 肉汤中，添加 0.8% (w/v) 甘氨酸和 6% (v/v) 正十二烷，使 ASNase 的总产量增加约 50% (15,108 IU L ^-1 )与使用不添加这些物质的相同培养基的生产相比，细胞外酶生产力提高了 16 倍 (484 IU L ^-1  h ^{-1 )。}在诱导步骤后 24 小时，大部分酶 (89%) 被分泌到培养基中。这种提议的方法提出了一种简单的策略来增加大肠杆菌中 ASNase 的细胞外产量。