Evaluating the potential of Halomonas pacifica DJ6.1 L-asparaginase: statistical production optimization, biochemical...

The study displays attributes of Halomonas pacifica DJ6.1 L-asparaginase, an extracellular enzyme from a haloalkalitolerant bacterium. The production parameters were optimized using response surface methodology, followed by enzyme purification via size exclusion and ion-exchange chromatography, achieving a 15.4-fold purification with a yield of 18.33 %. It catalyzed L-asparagine across a broad pH (4-10) and temperatures (10-100 °C), with optimal catalysis at pH 9 and 60 °C. It demonstrated 87 % reduction in acrylamide formation during French fry preparation when combined with a blanching process. Further, its cytotoxicity assays using human colon cancer (Caco-2) and normal skeletal muscle (L6) cell lines revealed selective inhibition of cancer cell proliferation, with minimal cytotoxic effects on normal cells. Apoptotic events in cancer cells were confirmed via DAPI and AO/EB staining, highlighting features such as nuclear damage, chromatin condensation, and characteristic morphological changes. Reactive oxygen species (ROS) analysis showed increased oxidative stress in enzyme-treated cancer cells. The gene expression analysis also indicated that the pro-apoptotic gene, Bax and the anti-apoptotic gene, Bcl2 were upregulated and downregulated, respectively. Thus, the findings suggest that H. pacifica DJ6.1 L-asparaginase holds promise for both food safety and anticancer applications.