Metallic nanoparticles and photosynthesis organisms: Comprehensive review from the ecological perspective.

This review presents a comprehensive analysis of the ecological implications of metallic nanoparticles (MNPs) on photosynthetic organisms, particularly plants and algae. We delve into the toxicological impacts of various MNPs, including gold, silver, copper-based, zinc oxide, and titanium dioxide nanoparticles, elucidating their effects on the growth and health of these organisms. The article also summarizes the toxicity mechanisms of these nanoparticles in plants and algae from previous research, providing insight into the cellular and molecular interactions that underpin these effects. Furthermore, it discusses the reciprocal interactions between different types of MNPs, their combined effects with other metal contaminants, and compares the toxicity between MNPs with their counterpart. This review highlights the urgent need for a deeper understanding of the environmental impact, considering their escalating use and the potential risks they pose to ecological systems, especially in the context of photosynthetic organisms that are vital to ecosystem health and stability.

Cu, Ni, and Zn effects on basic physiological and stress parameters of Raphidocelis subcapitata algae.

The submitted work observed Cu, Ni, and Zn effects on selected physiological and stress parameters of the alga Raphidocelis (Pseudokirchneriella) subcapitata. In 96-h experiments, EC50 values for algal specific growth rates (SGR) inhibition in Cu, Ni, and Zn presence were estimated as 0.15, 0.50, and 0.20 mg l-1. In addition to growth inhibition, the effect of metals at various concentrations on algal SGR was also monitored. While these experiments confirmed approximately the same toxicity of Zn and Cu on SGR, Ni toxicity on this parameter was observed as the lowest. In terms of the effect of metals on the level of selected photosynthetic pigments, chlorophyll a, chlorophyll b, and carotenoids, the following inhibition orders can be established: Zn > Cu > Ni, Ni > Cu > Zn, and Ni > Cu ≥ Zn, respectively. As a novelty of our research, we included monitoring and evaluation of the intensity of stress, which was the response of algal cells to the presence of Cu, Ni, and Zn, and its correlation with respect to production factors and metal accumulation in algal cells. As stress factors, thiol (-SH) group and TBARS (thiobarbituric acid reactive substances) as significant indicators of lipid level peroxidation were determined. The content of -SH groups depended on the concentration of metal, and its level was the most stimulated by Zn, less by Cu and Ni. The TBARS content was 2 to 5 times higher in Cu than in Zn or Ni presence. In the presence of Zn and Ni, TBARS content reached approximately the same levels. For this parameter, the following rank order can be arranged: Cu >> Ni ≥ Zn. While Cu and Ni accumulation in R. subcapitata was confirmed, Zn accumulation was not determined or was below the detectable limit. Regression analyses revealed significant positive correlation between Cu accumulation and TBARS while carotenoids as possible antioxidants confirmed with TBARS mostly negative correlations.

Assessment of the suitability of phytotoxkit plastic vertical containers compared with petri dishes for standard seedling growth tests.

This study compares two cultivation methods (Petri dishes vs. Phytotoxkit containers; tap water vs. Knop's solution) for standard seedling growth tests. Seeds and young seedlings of Sinapis alba and Hordeum vulgare were used as study subjects and the adverse effect of Cd was assessed. Under testing conditions, only H. vulgare showed a significant decrease in seed germination in Petri dishes when tap water was used as the growth medium (70.8 % ± 46.4 %). No significant differences in IC50 values were found in either plant type for root growth between plants cultivated in Phytotoxkit containers and those cultivated in Petri dishes. The same findings were confirmed for shoot growth in H. vulgare, but not in S. alba. Suitability of Phytotoxkit containers over traditionally used Petri dishes for phytotoxicity determination was confirmed by higher correlation coefficients for all tests.

Arsenic and selenium interactive effect on alga Desmodesmus quadricauda.

Substances known to be toxic in one-component solutions often exhibit unexpected effects when present in mixtures. Only a few efforts have been made to assess the effect of As-Se mixture in algae or plants in general. Due to the lack of information on this topic, the aim of this study was to examine the As-Se interactive effect in the alga species Desmodesmus quadricauda. The initial density of algal cells was 1.9×10(4), cultures were permanently illuminated (70µEm(-2)s(-1)) and As and Se adverse effect was expressed as EC (effective concentration) value. For all experiments three EC (EC(10), EC(20), EC(50)) values for both metalloids were used: for As 26.20, 29.05, 35.38mg L(-1) and for Se 1.93, 3.65, 12.24mg L(-1), respectively. During this study algal biomass growth, lipid peroxidation and protein-bound thiol content parameters were used to assess the As-Se interactions. The reciprocal effect of the elements on their uptake by the alga was also determined. The As-treated algae supplemented with Se exhibited impaired growth indicating a synergistic interaction between the two elements. In samples treated with As-Se mixture, the total algal As content showed marked increase depending on the Se concentration in the mixture. Se uptake was also positively affected by rising As concentrations in the mixture. Consequently, the As-Se-treated algae experienced greater damage to membranes, evidenced by marked elevation of the TBARS (thiobarbituric acid reactive substances) content. The TBARS content increased to a maximum level by 29.05mg L(-1) of As and 3.65mg L(-1) of Se, which was around 70 percent higher than that of the control. The thiol content was very close to that of the control treatment over the entire concentration range and for all As and Se combinations tested. Possible explanation for the synergism observed in D. quadricauda, is that the elevated uptake of As and Se upon their interaction and impaired antioxidant system, has added to the toxicity of the elements.

Removal of arsenic from aqueous environments by native and chemically modified biomass of Aspergillus niger and Neosartorya fischeri.

Arsenic removal from aqueous solutions by biomass of two fungal strains, Aspergillus niger and Neosartorya fischeri, was assessed. The biosorption capacity of fungal biomass was studied within the As(V) concentration range of approximately 0.2 to 5.0 mg L(-1) at two different pH values (pH 5 and 7). With increasing initial arsenic concentration, the biosorption capacity of both fungal strains increased almost linearly and achieved the sorption capacity of 0.317 and 0.124 mg g(-1) for biomass of N. fischeri and A. niger, respectively. The effect of biomass treatment with FeCl3 and HCI on As(III) and As(V) uptake was also studied. The optimum biosorption pH as well as the effect ofbiomass treatment was found to be dependent on the fungal strain used. Treatment with FeCl3 and HCl did not result in any significant increase in arsenic uptake. To the contrary, treatment with ferric oxyhydroxide was found to be very effective and virtually 100% of the arsenic was removed from the samples of contaminated natural water.

Assessment of Cr and Ni phytotoxicity from cutlery-washing waste-waters using biomass and chlorophyll production tests on mustard Sinapis alba L. seedlings.

BACKGROUND, AIM, AND SCOPE: The aim of this work was to determine phytotoxicity of washing waste-waters from a cutlery production line with high content of Cr and Ni. These waters were previously classified, without verification, as dangerous and it is now necessary to question the justice of the present classification under the new legislation for waste management (Waste Law No. 223/2001) in the Slovak Republic. METHODS: Young seedling of the dicotyledon terrestrial plant mustard Sinapis alba L. were used for determination of the dry and fresh root and shoot biomass and photosynthetic pigment production. Observed parameters were evaluated in laboratory experiments with three types of washing waste-waters from a cutlery production line. All contamination of tested washing waste-waters came from heavy metals (Ni, Cr), non-polar extractable compounds (NEC; residues of oils and waxes from polishing of stainless steel cutlery) and detergents (used for cutlery degreasing). Photosynthetic pigments (chlorophyll a, b, and total carotenoids) were extracted in 96% ethanol and measured spectrophotometrically at 665, 649, and 470 nm. All phytotoxicity tests were carried out in triplicate, and they included a control in tap water. RESULTS: All tested washing waters reduced root dry mass, whereas the shoot dry mass was either unaffected or it increased. The tested washing waters' effect was stronger on fresh mass production than on dry mass production. This indicated problems in water reception and translocation. The adverse effect on photosynthetic pigments production increased only slowly with remaining washing waste-water concentration. Almost all Chl a/b ratios were the same as for the control and this indicated no significant differences in the reduction of either a or b chlorophylls. As opposed to chlorophylls, carotenoids content increased in the presence of tested washing waste-waters and equaled or exceeded their content in the control. As the ratio of Chl(a + b)/Car was lower than that for the control for almost all tested samples, a stronger reduction in chlorophylls than in carotenoids was confirmed. DISCUSSION: The phytotoxicity of waste-waters from cutlery production line washing reservoirs was evaluated and the effects on dry and fresh mass production and photosynthetic pigments amount was discussed as Cr and Ni toxicity. CONCLUSIONS: It is concluded from the present study that washing waste-waters from cutlery production line are quite toxic to plants, thus reducing biomass and photosynthetic pigment production and influencing water translocation through the plant. RECOMMENDATIONS AND PERSPECTIVES: These determined adverse effects of washing waste-waters from this cutlery production line classified them as too dangerous to be spread on open-land soil. On the basis of this study, high toxicity of the presented waste-waters from metal surface-finishing as well as justness of their liquidation as hazardous wastes by legally assigned persons were recommended.

Se(IV) phytotoxicity for monocotyledonae cereals (Hordeum vulgare L., Triticum aestivum L.) and dicotyledonae crops (Sinapis alba L., Brassica napus L.).

The phytotoxicity of Se(IV) was determined through root and shoot growth inhibition, biomass (dry (DM), fresh (FM)) production, water content, photosynthetic pigment (chlorophyll a, chlorophyll b and carotenoids) levels and Se accumulation in the roots and shoots. The sensitivities of monocotyledonae (Hordeum vulgare, Triticum aestivum) and dicotyledonae plants (Sinapis alba, Brassica napus) were also compared. Except for H. vulgare, Se(IV) inhibited root growth more than shoot growth. As for biomass production, Se reduced both FM and DM of all studied plants' roots. Although in shoots FM was decreased with increased Se concentration, DM was reduced only in monocotyledonae plants (H. vulgare, T. aestivum). No significant differences between roots and shoots were confirmed for the DM/FM relationship, except for S. alba seedlings. In all of the tested plants, except for B. napus, chlorophyll b was the strongest reduced pigment. Accumulation of Se was higher in the roots than in the shoots of all studied plants. Selenium concentration in the roots was at least 3-times higher than that in controls. Se(IV) accumulation in the shoots was not significantly different from that in controls. The exception was confirmed only for B. napus (87 mg Se(IV)l(-1)) and T. aestivum (36 mg Se(IV)l(-1)).

The degradative action of peroxynitrite on high-molecular-weight hyaluronan.

OBJECTIVES: This contribution presents the results of the kinetics of HA degradation by peroxynitrite, which represents one of the main reactive oxygen species degrading various biomacromolecules under inflammatory conditions. METHODS: Two simple procedures have been adapted to prepare sodium peroxynitrite: the first containing an excess of H(2)O(2), and the second in which the H(2)O(2) excess had been decomposed by MnO(2) treatment. The kinetics of hyaluronan degradation by action of peroxynitrite was monitored by rotational viscometry. RESULTS: High-molecular-weight hyaluronan was degraded by peroxynitrite. The degradation was increased in the presence of ONOO(-) previously treated by MnO(2) in order to remove residual hydrogen peroxide. One of the reasons of this finding could be that by the action of the residual metal the pathway of ONOO(-) decomposition starts to be manifested immediately on mixing traces of metals originally present in the HA sample with the ions of manganese. CONCLUSIONS: Trace amounts of transition metal(s) should be taken into consideration on evaluating the experimental results. Purchase of the marketed peroxynitrite product appears to be the appropriate approach to simplify and standardize the quality of ONOONa.