TY - JOUR AU - Elborai, Aliaa AU - Sayed, Rahma AU - Farag, Aida AU - Elassar, Samy PY - 2023/05/09 Y2 - 2024/03/29 TI - A HIGHLY PURIFIED L-GLUTAMINASE FROM IMMOBILIZED PSEUDOMONAS SP. RAS123 CULTURES WITH ANTITUMOR AND ANTIBACTERIAL ACTIVITIES JF - Journal of microbiology, biotechnology and food sciences JA - J microb biotech food sci VL - 13 IS - 1 SE - Biotechnology DO - 10.55251/jmbfs.5637 UR - https://office2.jmbfs.org/index.php/JMBFS/article/view/5637 SP - e5637 AB - <p>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 <em>Pseudomonas</em> sp. RAS123. The enzyme was produced from free cultures and from cultures immobilized on and in different supports. <em>Pseudomonas</em> 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 Mn<sup>2+</sup>, Mg<sup>2+</sup>, Ni<sup>2+</sup> and Fe<sup>2+</sup>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 IC<sub>50</sub> values of 122, 175, 195, 306, and &gt; 500 µg/ml, respectively. Also, the antibacterial effect of the enzyme showed activity against <em>Staphylococcus aureus</em>, <em>Bacillus subtilis</em>, <em>Streptococcus mutants</em>, <em>Enterobacter cloacae</em> and <em>Escherichia coli</em>. These findings demonstrate that L-glutaminase might be used in numerous biotechnological applications, particularly food and pharmaceutical processing.</p> ER -