Impact of nanoparticles on microalgae and the prospects for biofuel production: Current advancements and future outlook

Nanoparticles (NPs) are innovative, high-throughput materials that have revolutionized nearly every area of human life. Microalgae represent a highly favorable eco-conscious choice in the pursuit of biofuel production. The synthesis of biofuels such as biodiesel, bioethanol, bio-hydrogen, bio-methane, and syngas can utilize microalgal biomass as a feedstock. Microalgae cannot currently be used to produce large-scale biofuels due to a lack of economic viability. The addition of NPs to microalgal cultures can boost light conversion in the microalgae photobioreactor and increase CO₂ absorption yield. This study provides an in-depth review of the current trends and prospects of NPs applied to microalgae. It delves into how NPs can influence the metabolic pathways of microalgae and examines potential morphological toxicity. The research conducted in this area has revealed that the toxicity of NPs is influenced by various factors, including their nature (size, oxidation state, crystal structure), concentration, the composition of the cultivation media, and the specific microalgae species being used. This study suggested that the mechanism of nanoparticle internalization with microalgae via endocytosis, ion release (absorption through an ionic channel), shading influence, adsorption, and absorption by the pore route are all mechanisms by which NPs interact with microalgae. Moreover, the addition of NPs has demonstrated a significant positive impact on intracellular compound accumulation and overall growth.