A Highly Purified L-Glutaminase From Immobilized Pseudomonas Sp. Ras123 Cultures With Antitumor and Antibacterial Activities

Abstract

L-glutaminase (E.C.3.5.2.1) is an antineoplastic enzyme and in the present study, an extracellular L-glutaminase was produced from a marine local strain identified as Pseudomonas sp. RAS123. The enzyme was produced from free cultures and from cultures immobilized on and in different supports. Pseudomonas sp. RAS123 L-glutaminase produced from immobilized cultures was purified to homogeneity. The specific activity of the enzyme reached 698.655 U/mg protein, with Km and Vmax value of 3.2 mg/ml and 2000 U/ml, respectively. A single band with a molecular weight of about 32.0 kDa was produced by the purified enzyme on SDS-PAGE. Further findings indicated that the pure enzyme's maximum activity occurred at 50°C and pH 9. The enzyme was stable at 60°C for 60 min and in the pH range of 8.0 to 10.0, The effect of chemicals showed that Mn2+, Mg2+, Ni2+ and Fe2+activated the enzyme, while SDS (10% w/v) strongly inhibited the activity of the enzyme. The purified enzyme showed cytotoxic activity against HCT-116, HepG2, MCF-7, HeLa, and CCL-86 cell lines tested with IC50 values of 122, 175, 195, 306, and > 500 µg/ml, respectively. Also, the antibacterial effect of the enzyme showed activity against Staphylococcus aureus, Bacillus subtilis, Streptococcus mutants, Enterobacter cloacae and Escherichia coli. These findings demonstrate that L-glutaminase might be used in numerous biotechnological applications, particularly food and pharmaceutical processing.

L-glutaminase Production from New Halophilic Marine Streptomyces griseorubens NAHE Isolated from Mangrove Sediment, Red Sea, Egypt

“…These optimum conditions improved the average yield of L-glutaminase from S. griseorubens NAHE culture by 1.47-fold in comparison with the conditions implemented prior to optimization. The use of PBD in optimization studies has shown its efficacy in improving the yield of L-glutaminase (Iyer & Singhal, 2010; Pandian et al, 2014;Jesuraj et al, 2017;Elborai et al, 2023). The synthesis of Lglutaminase by B. subtilis JK-79 was greatly improved with the use of PBD, resulting in much higher enzyme titers.…”

“…In contrast, the cells that were trapped inside the Ca-alginate matrix resulted in slow diffusion of glutamine and air into the alginate beads, reducing the production of the L-glutaminase enzyme. It was suggested that sodium alginate is the most suitable matrix for immobilizing microorganisms to produce different enzymes (Divatar et al, 2015;Shen et al, 2021;Elborai et al, 2023).…”