Bacterial pigments (e.g.,
melanin and
carotenoids) are considered to be among the most important secondary metabolites due to their various pharmacological activities against
cancer and microbial resistance. Different pigmented bacterial strains were isolated from soil samples from El Mahmoudiyah governance and screened for their antimicrobial activity. The most promising pigment producer was identified as Micrococcus lylae MW407006; furthermore, the produced pigment was identified as
echinenone (β-
carotene pigment). The pigment production was optimized through a central composite statistical design to maximize the biomass production, pigment concentration, and the antimicrobial activity. It was revealed that the most significant fermentation parameters were the
glucose (as a
carbon source) and
asparagine (as a
nitrogen source) concentrations. Nano-
echinenone was synthesized using the ball milling technique, characterized, and finally assessed for potential antimicrobial,
antioxidant, and antitumor activities. The data revealed that the synthesized nano-
echinenone had higher antimicrobial activity than the crude pigment. The cytotoxic potency of
echinenone and nano-
echinenone was investigated in different cell lines (normal and
cancer cells). The inhibition of cell proliferation and induction of cell death was observed in Caco-2 and Hep-G2 cells. The data proved that nano-
echinenone is a suitable candidate for use as a safe antimicrobial and anti-
hepatocellular-carcinoma agent.