Algal nanobionics and a nanobiohybrid system of biosynthesized ZnO-NPs to augment the cellular accumulation of biomolecules and its effect on microalgae

Algal nanobionics leverages nanotechnology to enhance microalgae-based biotechnology. This study presents an approach to synthesize zinc oxide nanoparticles (ZnO-NPs) from macroalgal bloom extract (MBE) and integrate them at various concentrations into Chlorella sorokiniana. The impact of MBE–ZnO-NPs on biocompatibility, biomass productivity, pigment contents, and intracellular dispersion was assessed. Results indicated that a 5 ppm concentration of MBE–ZnO exhibited high compatibility and significantly increased reactive oxygen species (ROS) levels (7.19 ± 0.4 μmol H2O2 g−1) and photosynthetic yields of chlorophyll ‘a’ (Chl ‘a’ 28.30%), chlorophyll ‘b’ (Chl ‘b’ 44.78%), and carotenoids (Car 37.94%) in microalgae. The lipid and protein contents increased, whereas carbohydrate content was reduced in the MBE–ZnO-NP-treated biomass. In addition, the biomass treated with MBE–ZnO NPs exhibited 29.28 mg/100 mg of total amino acid (AA) content, including 7.65 mg/100 mg of essential and 21.62 mg/100 mg of non-essential AAs. These findings highlight the necessity of green and natural NPs in optimizing and bioprospecting the potential of algae for sustainable ecological and economic approaches.