Original Articles
El-Sayed E. Mostafa, Azza M. N
Abstract
Fifty Streptomyces isolates were collected and screened for their capability for L-asparaginase (L-ASNase) activity. The SAH1_CWMSG isolate was found to be a promising L-ASNase producer. The SAH1_CWMSG strain possesses phenotypic characteristics typical of Streptomyces. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed (99%) similarity with Streptomyces ghanensis. The strain was named Streptomyces ghanensis SAH1_CWMSG (Gen Bank ID: KT953341).The crude enzyme showed an antifungal activity against common fungal strains. In vitro, anticancer evaluation revealed that the pure enzyme exerted its action in HepG2 and MCF-7 cancer cell lines and showed promising anticancer activity compared to doxorubicin. SAH1_CWMSG strain produced L-ASNase activity of 13 IU under submerged fermentation by shake flask. The maximal activity of 106.90 IU was obtained using ammonium sulfate as nitrogen source at 28°C and 120 h on 200 rpm. The purified enzyme has Km and Vmax of 27 mMol and 69 IU/mL, respectively, with molecular weight of 38 kDa by SDS-PAGE. This is the first report on the production and characterization of L-ASNase by the SAH1_CWMSG strain. These results provided additional information on L-ASNase production and its application as an anticancer agent