Cumulative effect of zinc oxide and titanium oxide nanoparticles on growth and chlorophyll a content of Picochlorum sp.

Abstract

The use of nanoparticles (NPs) is of increasing significance due to their large potential for various applications. Great attention should be paid on the possible impacts of nanoparticles on the environment as large amounts of them may reach the environment by accident or voluntarily. Marine algae are potential organisms for usage in nanopollution bioremediation in aquatic system, because of their ability to adapt to long exposure to NPs. Thus, it is of prime importance to study the possible interactions of different NPs with microalgae in assessing their potential environmental risks. Most studies on potential environmental effects of ZnO and TiO2 NPs have been performed independently and following the widely accepted, standardized test systems, which had been developed for the characterization of chemicals. In this study, we have examined the cumulative effect of ZnO and TiO2 NPs on Picochlorum sp. in addition to the individual effects of these NPs over 32 days. Our results indicate that the toxicity and availability of NPs to marine algae are reduced by their aggregation and sedimentation. NPs are found to have a negative effect on algal growth and chlorophyll a concentration during the early growth stages. In contrast, the case is reversed during the late growth stages. There is no significant difference between the effect of the NPs when they are used separately and when both ZnO and TiO2 are used together in the test (P > 0.05).

Effects of TiO2 nanoparticles and water-deficit stress on morpho-physiological characteristics of dragonhead (Dracocephalum moldavica L.) plants

“…Negative effect of TiO 2 NPs on chlorophyll a concentration during the early growth stages of algae (Picochlorum sp.) has been also reported (Hazeem et al, 2016). However, there are other diverse reports showing TiO 2 NPs have no effect on chlorophyll and carotenoid content in bread wheat (Larue et al, 2012) and even promoted chlorophyll formation in spinach and mung bean (Raliya et al, 2015).…”

Titanium Dioxide Nanoparticles Improve Growth and Enhance Tolerance of Broad Bean Plants under Saline Soil Conditions

“…Nanotechnology offers a great advantage in the field of chemical priming as the effectiveness of chemicals can be enhanced in their nano-form, thus reducing their environmental load (Khan et al, 2017). A wide range of nanoparticles (NPs), such as zinc oxide (nZnO), titanium oxide (nTiO 2 ), cerium dioxide (nCeO 2 ), silicon dioxide (nSiO 2 ), magnetite (nFe 3 O 4 ), aluminium oxide (nAl 2 O 3 ), copper oxide (nCuO) and carbon nanotubes, have been tested for their potential towards growth promotion and stress amelioration in plants (Marchiol et al, 2016;Abdel Latef et al, 2017), diatoms (Deng et al, 2016) and algae (Hazeem et al, 2016). nTiO 2 is one of the major engineered NPs produced in large quantities by cosmetics, chemical, agriculture and food industries (Liu et al, 2014).…”

Assessing the Impact of Biologically Synthesized ZnO Nanoparticles as Source of Nutrient on the Growth of Zea mays L.

“…According to our results, seed priming may be an effective method to enhance the growth parameters. Seed priming with ZnO NPs has been reported by Munir et al (2016) As concern to nanoparticle dose, Hazeem et al (2016) reported lower Zn concentration in cucumber shoot with Zn NPs concentration of 125 mg/kg than 25 mg/kg which could be due to higher Zn levels that deform the plant cells. While, contrary to this, Moghaddasi et al (2017) reported higher Zn concentrations in plants treated with high NPs concentration and correlated it with higher penetration of NPs into plant cells However, more studies are required to understand the absorption mechanism within the plant cells.…”