The development of antimicrobial agents with excellent antimicrobial activity, high thermal stability, and non-toxic properties is an essential demand in food packaging, pharmaceutical, and biomedical applications. In the present study, MgO nanoflakes were synthesized via the co-precipitation method by varying calcination temperatures at 400, 500, and 600 °C. The effect of calcination temperature on the morphology, thermal stability, antimicrobial activity, and cytotoxicity of the MgO nanoflakes was analyzed. All synthesized MgO samples showed a Face-Centered Cubic (FCC) structure. As the calcination temperature increased, the MgO crystallite and particle sizes increased, whereas the surface area decreased. In addition, the MgO synthesized from higher calcination temperatures showed higher thermal stability and crystallinity. The MgO synthesized from the lower calcination temperatures (400 and 500 °C) showed superior antimicrobial activity against Escherichia coli (100% R) and Staphylococcus aureus (100% R) than that from the higher calcination temperature (600 °C). The cytotoxicity test demonstrates slight cytotoxicity in MgO-400 °C at concentrations ranging from 100 to 200 µg/mL. Interestingly, MgO-500 °C and MgO-600 °C demonstrate biocompatibility and exhibit non-cytotoxic effects, respectively, highlighting their potential for practical applications in active food packaging and biomedical fields.

: The variety of microorganisms represents the most prevalent sources utilized within diverse industries and research fields. Enzymes with microorganisms are applied in the use of industrial biotechnology. Since the dawn of civilization, there are techniques like extraction and fermentation that use plant or bacterial enzymes as well as other byproducts. Enzymes, the natural catalysts, are intricately involved in many aspects of life. Enzymes pose remarkable specificity for their substrate, which implies that these metabolic cycles in a living cell need to be executed by a team working in collaboration. The major sources of these enzymes are yeast, some fungi and bacteria. Just like all living forms, microbes interact with their environment in which they must live in order to survive. A large number of microorganisms that are capable of producing great varieties of enzymes are important in the production of bread, cheese, yogurt, beer, and many other foods. One of the most widely used lipolytic enzyme is lipase from various sources including food and dairy industry, leather, detergent, pulp and paper, bioenergy and even pharma. With the latest innovation in biotechnology, the need for organisms that produce different commercially important lipases which other strains of lipases do is increasing. Lipases produced from microbial cells have a major industrial significance because of their property of versatility and ease of mass production. This review seeks to clarify the sources of microorganisms, lipase production and purification processes, as well as the environmental and industrial uses of lipase enzymes. One-Sentence Summary: This manuscript explores the diverse microbial sources of lipase, their production processes and the crucial applications in industries such as food, pharmaceuticals, and biofuels.

Polylactic acid (PLA)-curcumin (CCM) composites, incorporating various contents of surface-functionalized dual-metal-doped copper oxide (SF-M-CuO), were prepared by the solution casting method. Synthesized composite films were evaluated for their antioxidant, biocompatible, photothermal, and antibacterial properties. The 4% CCM exhibits excellent compatibility based on total color difference, antioxidant activity, and controlled curcumin release behavior. In addition, different contents of SF-M-CuO (1–4%) were added to the PLA-4%-CCM polymer matrix. Synthesized composite films were characterized through functional, structural, and topographical analyses. FTIR and XRD analyses confirmed the successful incorporation of CCM and SF-M-CuO into the PLA matrix, which enhanced interfacial interactions and increased the crystallinity index by acting as effective nucleating agents. ABTS and DPPH radical scavenging assays revealed dose-dependent antioxidant activity due to the synergistic effects of CCM and SF-M-CuO. Biocompatibility evaluation using RAW 264.7 macrophage cells demonstrated non-toxic responses and enhanced cell proliferation in PLA-4%-CCM composite films containing up to 3%-SF-M-CuO. Among the fabricated films, PLA-4%-CCM-3%-SF-M-CuO exhibited superior photothermal performance and excellent antibacterial activity against Staphylococcus aureus and Escherichia coli, reducing bacterial counts to below the limit of detection. These findings demonstrate the potential of PLA-4%-CCM-3%-SF-M-CuO composite films as sustainable multifunctional materials for food safety and biomedical applications.