Lactococcus spp., mediated MgO nanoparticles: Assessment of antimicrobial and anticancer activities against intestinal disorder

•Bio fabricated MgO NPs using Lactococcus spp.•Bio fabricated MgO NPs were characterized by UV–Vis, FT-IR, XRD, FE-SEM, TEM and AFM.•MgO NPs were proven to be efficient antimicrobial and cytotoxicity activity. Owing to the obvious rise in junk foods, people are suffering from a variety of intestinal disorders, health problems besides the fact that these foods largely pollute our environment. This has become a major public concern. In this investigation, Lactococcus spp., was isolated and identified from cow’s milk and Magnesium oxide (MgO) nanoparticles (NPs) were fabricated using green method. The formation, shape, crystallinity, functional groups, morphology, topography and size of the green fabricated MgO NPs were validated by several characterizations such as UV–vis spectrometery, XRD, FT-IR, FE-SEM with EDX, AFM and TEM. Tetragonal crystalline structure of the synthesized NPs was studied by XRD and crystalline size was found to be 19 nm. The fabricated MgO NPs was investigated by FE-SEM with an average particle size of 32 nm. The well diffusion technique was used to examine the antimicrobial properties of fabricated MgO NPs against microbial infections. The cytotoxicity was assessed using the MTT and NRU tests. MTT and NRU evaluations of HT-29 cell lines revealed outstanding cytotoxic effects, with IC50 values of 82.3 and 36.8 g/mL, respectively. Therefore, the present findings proved that the fabricated MgO NPs have potential cell viability and possess antimicrobial agents.