Enhanced Production of Novel Glutaminase Free Recombinant L-Asparaginase II of Erwinia Carotovora Subsp. Atroseptica Scri 1043 in Escherichia Coli BL21 (DE3) in a Batch and Fed-Batch Culture

L-asparaginase (E.C.3.5.1.1) is used for treatment of acute lymphoblastic leukemia. It is also used as a processing aid for reducing the formation of acrylamide in starchy foods preparations. In this study, the effects of glucose, controlled pH and Dissolved Oxygen Concentration (DOC) level on cell growth and production of novel glutaminase free recombinant L-asparaginase II of Erwinia carotovora subsp. atroseptica SCRI 1043, expressed in Escherichia coli BL21 (DE3) were investigated in a batch bioreactor using Taguchi experimental design technique. At optimum circumstances of glucose (1.5 g/l), controlled pH (7.0) and DOC (40%), the maximum dry cell weight and production of recombinant L-asparaginase II was found to be 1.84 g/l and 24.57 U/ml, respectively. Fed-batch culture is used frequently to increase expression of heterologous recombinant proteins in Escherichia coli. Therefore, the production of recombinant L-asparaginase II was performed in fed batch culture. In fed-batch fermentation, 7.35 g/l of dry cell weight and 96.78 U/ml of recombinant glutaminase free L-asparaginase II were achieved, corresponding to about four fold increase in dry cell weight and production as compared with the batch culture.