Influence of Interaction Between α-Fe2O3 Nanoparticles and Dissolved Fulvic Acid on the Physiological Responses in Synechococcus sp. PCC7942

Abstract

The ecotoxicity of α-FeO nanoparticles (NPs) and its interaction with a typical natural organic matter (NOM), fulvic acid (FA) on the physiological responses of Synechococcus sp. PCC7942 was studied. α-FeO NPs inhibited the algae growth at concentration higher than 10 mg L and induced oxidative stress, indicated by enhanced antioxidant enzymes activities, elevated protein and sugar content. FA could efficiently recover cell growth and reduce antioxidant enzyme activities which induced by α-FeO NPs, indicating the toxicity of NPs was alleviated in the presence of FA. α-FeO NPs could form large aggregates coating on cell surface and inhibit cell growth. FTIR spectra verified FA interacted with α-FeO NPs through carboxyl groups, partly replaced the binding sites of α-FeO NPs on algal cell walls, thus reduced NPs aggregates coating on cell surface. This favors reducing the oxidative stress caused by direct contact and increasing light availability, thus mitigate NPs toxicity.

Algal extracellular polymeric substances (algal-EPS) for mitigating the combined toxic effects of polystyrene nanoplastics and nano-TiO2 in Chlorella sp.

“…The same patternwas observed in Synechoccocus sp. when it was treated with iron nanoparticles coated with fulvic acid (a form of NOM) (He et al 2017). In response to the ROS produced in the presence of NMs, SOD could get activated in Chlorella sp., and convert superoxide radicals into H 2 O 2 .…”

Effects of manufactured nanomaterials on algae: Implications and applications

“…On the other hand, algae is considered as a unique feedstock to produce biofuel (Saber et al, 2016;Yap et al, 2021), while the efficiency and cost-reduction of the cultivation and harvesting steps remain key obstacles (Jones and Mayfieldt, 2012;Kim et al, 2013;Fazal et al, 2021). Due to the MNMs-algae interactions, the biofuel production could be promoted via the induction of intracellular lipid accumulation by nutrient competition and/or stress environments (Farooq et al, 2016;Kim et al, 2016;Liu et al, 2016;He et al, 2017), enhancement of cell growth and/or pigment by light scattering (Torkamani et al, 2010;Pattarkine and Pattarkine, 2012;Eroglu et al, 2013), increased cell separation efficiency and processing time in culture media (Borlido et al, 2013;Hu et al, 2013), and integrated one-pot harvest/cell division (Lee et al, 2014).…”