Novel nanoconjugates of metal oxides and natural red pigment from the endophyte Monascus ruber using solid‑state fermentation

<p>Background Antimicrobial resistance has emerged as a major global health threat, necessitating the urgent devel opment of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes.
With this view, we developed three novel nanoconjugates using microbial natural pigment for efective application
against certain pathogenic microbes.
Results A natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied
to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized
by diferent techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated.
Moreover, the antibioflm, protein leakage, growth curve, and UV light irradiation efect of the synthesized nanoconju gates were also studied. Our results confrmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO,
RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fun gal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO
against the tested microbes. The highest % inhibition of bioflm formation by the RP-ZnO nanoconjugate. Membrane
leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more efective than RP-MgO and RP-CuO nanoconju gates. Finally, UV light irradiation intensifed the antibiotic action of the three nanoconjugates and RP-ZnO potential
was greater than that of the RP-MgO, and RP-CuO nanoconjugates.
Conclusion These fndings pave the way for exploiting the synthesized nanoconjugates as potential materials in bio medical applications, promoting natural, green, and eco-friendly approaches</p>