Production of L-Asparaginase II by Recombinant Escherichia Coli Cells

Abstract

The current paper presents some studies focused on the development of an experimental system to overproduce L-asparaginase II in two local isolated E. coli strains (E. coli ICCF20 and E. coli IBB13) using recombinant DNA methods in order to transfer a DNA fragment able to improve the level of enzyme activity. Chromosomal DNA from E. coli IBB13 was isolated and cleaved with Bam HI restriction enzyme. The Bam HI restriction fragments were cloned in pUC19 and the recombinant molecules were used for the transformation of E. coli HB101. The recombinant plasmids isolated from E. coli HB101 transformants (24 transformants resistant Apr Lac-) were isolated and used for the transformation of E. coli E13 and E. coli E20. The efficiency of transformation with recombinant plasmids was reduced; all the colonies grown on selective medium were tested for L-asparaginase production, by qualitative and quantitative assays. Six of the transformants have shown a level of L-asparaginase II higher with 63-117% than the parental strains.