Zinc oxide nanoparticles (ZnO-NPs) are a type of metal oxide nanomaterial, recognized as a valuable and adaptable inorganic compound owing to its distinctive physical and chemical properties. Nanosized ZnO particles exhibit substantial antibacterial properties attributable to their diminutive size, which can activate various bactericidal mechanisms within the bacterial cell, including interactions with the bacterial surface or core, the generation of reactive oxygen species (ROS), the release of Zn2+, and potential endocytosis by cells. ZnO NPs nanoparticles were extracellularly produced using pigment extracts from the PP6 strain. Agar well screening indicated that PP6 secondary metabolites possess antibacterial properties. UV–Vis spectroscopy was used to analyze the external growth of nanoparticles. Scanning Electron Microcopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction (XRD) techniques were employed to analyze the shape, stability, crystalline structure, and coating of strain PP6 ZnO NPs. The PP6 ZnO NPs demonstrated an antibiofilm impact on the bacterial pathogens tested, which was dependent on the dosage. Elevated levels of lipid peroxidation (LPO) and reduced antioxidant activity are indicative of apoptosis in cancer cells. The synthesized ZnO NPs nanoparticles were assessed for their anticancer properties by performing the MTT assay on HT-29 human colorectal adenocarcinoma cells. ZnO NPs nanoparticles exposed to HT-29 cells the viability was reduced significantly in proportion to the concentration of nanoparticles. Additional comprehensive study will be needed to fully understand their mechanism.