Title:Bioprocess Optimization for Enhanced Production of L-asparaginase via Two Model-Based Experimental Designs by Alkaliphilic Streptomyces fradiae NEAE-82
VOLUME: 9 ISSUE: 1
Author(s):Hoda M. Soliman, Noura El-Ahmady El-Naggar* and Sara M. El-Ewasy
Affiliation:Department of Botany, Faculty of Science, Mansoura University, 35516, Mansoura, Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, 21934, Alexandria, Department of Bioprocess Development, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technological Applications, 21934, Alexandria
Keywords:L-asparaginase production, Streptomyces fradiae NEAE-82, Plackett-Burman and Box-Behnken designs.
Abstract:Background: L-asparaginase is one of the most widely used chemotherapeutic agents for
the treatment of a variety of lymphoproliferative disorders and particularly acute lymphoblastic leukemia.
Due to increased applications of L-asparaginase in several industrial fields including food processing
and medical fields, its production needs to be increased to several folds.
Objective: The aim was (i) to identify the significant factors which affect L-asparaginase production by
Streptomyces fradiae NEAE-82 and (ii) to achieve higher production of L-asparaginase.
Methods: Sixteen assigned factors and three dummy factors were screened using Plackett-Burman experimental
design to determine the most important factors for the production of L-asparaginase by
Streptomyces fradiae NEAE-82.
Results: L-asparagine was determined to be the most significant positive independent factor (P-value
0.0092) affecting L-asparaginase production by Streptomyces fradiae NEAE-82 followed by pH and
NaCl with significant P-values of 0.0133 and 0.0272; respectively. These factors were further optimized
by Box-Behnken experimental design. The optimized fermentation conditions, which resulted in
the maximum L-asparagine activity of 53.572 UmL-1 are g/L: dextrose 4, L-asparagine 15, KNO3 2,
MgSO4.7H2O 0.5, K2HPO4 1, FeSO4.7H2O 0.02, NaCl 0.2, ZnSO4 0.01 and inoculum size 2 %, v/v for
7 days incubation at temperature 37°C, agitation speed 100 rpm, pH 8.5.
Conclusion: A total of 3.41-fold increase in the production of L-asparaginase was achieved in the medium
after statistical improvement (53.572 UmL-1) as compared to the unoptimized basal medium used
prior to the application of Plackett-Burman (15.704 UmL-1).
