Development of a Strategy for Enhancing the Biomass Growth and Lipid Accumulation of Chlorella sp. UJ-3 Using Magnetic Fe3O4 Nanoparticles

Abstract

In this study, magnetic Fe3O4 nanoparticles (NPs) were used as an effective enhancer to increase the biomass and total lipid production of Chlorella sp. UJ-3. It was found that the biomass of algal cells increased significantly when they were exposed to low concentrations of Fe3O4 NPs (20 mg/L), while the best total lipid content of algal cells was achieved when they were exposed to high concentrations of Fe3O4 NPs (100 mg/L). Therefore, we established a strategy to promote the growth and lipid accumulation of microalgae by initially exposing the algal cells to low concentrations of Fe3O4 NPs and then treating them with an increased concentration of Fe3O4 NPs after 12 days of culture. For this strategy, the biomass and total lipid production of algal cells increased by 50% and 108.7%, respectively, compared to the untreated control. The increase in lipid production and change in the fatty acid composition of Chlorella cells were found to help them to cope with the increased number of reactive oxygen species produced due to oxidative stress in alga cells after the addition of Fe3O4 NPs. This study provided a highly efficient way to improve the lipid production of microalgae using nanoparticles.

Effects of citrate-stabilized gold and silver nanoparticles on some safety parameters of Porphyridium cruentum biomass

“…There are cases where low concentrations of nanoparticles have shown positive effects, while high concentrations have exerted negative effects ( Pádrová et al, 2015 ; Cepoi et al, 2020 ). In other cases, however, an inverse relationship has been revealed ( Wang et al, 2021 ). In the context of nanoparticle effects on organisms, the notion of low and high concentrations refers more to the effects produced rather than the quantity.…”

“…A similar response was found under the growth conditions of mixotrophic Chlorella sp . UJ-3 in the presence of low concentrations of Fe 3 O 4 nanoparticles in nutrient medium ( Wang et al, 2021 ). In the case of AuNPs of both sizes, lipid content in biomass was significantly higher, but the effect was not concentration–dependent.…”

“…Thus, stimulatory effects of some nanoparticles on lipid accumulation have been revealed in other algal cultures treated with different types of nanoparticles: Oedogonium sp., Cladophora sp., Ulothrix sp., and Spirogyra sp. using AgNPs ( Hasnain et al, 2023 ); Scenedesmus obliquus exposed to Fe 2 O 3 and Fe 3 O 4 nanoparticles ( He et al, 2017 ; Wang et al, 2021 ); Trachydiscus minutus , Desmodesmus subspicatus and zerovalent iron (ZVI) nanoparticles ( Pádrová et al, 2015 ); Chlorella vulgaris upon influence of TiO 2 nanoparticles and MgNPs ( Kang et al, 2014 ; Sibi et al, 2017 ).…”

Biotechnological Approaches for Biomass and Lipid Production Using Microalgae Chlorella and Its Future Perspectives

“…Many studies have shown the importance of cultivation conditions for microalgal growth and lipid accumulation. Nutrients [ 19 , 20 ], high salinity [ 21 , 22 ], metal ions [ 23 ], light intensity, temperature, pH, and abiotic/biotic treatments are regarded as critical parameters for microalgal growth and lipid accumulation. This review presents updated research on Chlorella biomass and lipid production, published mainly in the last five years, and discusses the subsequent progress and perspectives.…”

Cultivation and Biorefinery of Microalgae (Chlorella sp.) for Producing Biofuels and Other Byproducts: A Review

“…in POME as medium was obtained in the optimal condition of 10.9% CO 2 and 9963.8 lux of light intensity through central composite designs [3]. The microalgal growth and lipid production were enhanced by the addition of phytohormone indole-3-butyric acid (IBA) [2], ferroferric oxide (Fe 3 O 4 ) nanoparticles [29], sodium nitrate (NaNO 3 ) [30], glycerol [31], etc. Additionally, the producing biomass microalgal CO 2 fixation can be used to produce specific components that can be refined as high-value byproducts to realize the economic sustainability [32].…”