Assessment of phytoremediation potencial of Allium cepa L. in raw sewage treatment

Assessment of synthetic food dye erythrosine induced cytotoxicity, genotoxicity, biochemical and molecular alterations in Allium cepa root meristematic cells: insights from in silico study

Background

Synthetic food dyes are being exponentially used in food products and scarce studies regarding their toxicities and safety raise concern. Erythrosine is one of the synthetic food dyes being used in jams, fig, pineapple marmalades, dairy products, soft drinks, pickles, relishes, smoked fish, cheese, ketchup, maraschino cherries and a variety of other foods.

Methodology

In this study the cyto-genotoxic effect of erythrosine was evaluated, using root meristematic cells of Allium cepa for the cellular and molecular alternations at concentrations 0.1, 0.25, 0.5 and 1 mg/mL.

Results

The results revealed a significant decrease of 57.81% in the mitotic index after 96 h at the 0.1 mg/mL concentration. In biochemical analysis, the malondialdehyde content increased significantly (5.47-fold), while proline content, catalase activity and superoxide dismutase activity decreased gradually in a concentration-dependent manner showing a maximum decrease of 78.11%, 64.68% and 61.73% respectively at the highest concentration after 96 h duration. The comet assay revealed increased DNA damage with increasing concentration and attenuated total reflectance- Fourier transform infrared spectroscopy (ATR-FTIR) analysis showed significant alterations in biomolecules as indicated by multivariate analysis, i.e. Principal Component Analysis (PCA). Furthermore, molecular docking demonstrated a strong binding energy (Gbest = -11.46 kcal/mol) and an inhibition constant (Ki) of 3.96 nM between erythrosine and the DNA minor groove.

Conclusion

The present study's findings revealed the cytotoxic and genotoxic potential of erythrosine on A. cepa root cells. Further, the study also proposed the usefulness of A. cepa as a model system for studying the toxicity of food additives.

Phytoremediation as a way to clean technogenically polluted areas of Kazakhstan

One of the most serious problems worldwide is heavy metal (HM) pollution. HMs can have a toxic effect on human health and thus cause serious diseases. To date, several methods have been used to clean environments contaminated by HMs, but most of them are expensive, and it is difficult to achieve the desired result. Phytoremediation is currently an effective and affordable processing solution used to clean and remove HMs from the environment. This review article discusses in detail the technology of phytoremediation and mechanisms of HM absorption. In addition, methods are described using genetic engineering of various plants to enhance the resistance and accumulation of HMs. Thus, phytoremediation technology can become an additional aid to traditional methods of purification.

Phyto-genotoxicity assessment of different associations between sludges from Water and Sewage Treatment Plants, before and after the bioremediation process

Water Treatment Plants (WTP) and Sewage Treatment Plants (STP) generate residues known as sludge (WS and SS, respectively). SS and WS present some positive characteristics for reuse in agriculture. The aim of the present study was to evaluate, using the Allium cepa test, the effectiveness of the bioremediation process in the detoxification of SS and WS sludges. In this study, the phytotoxic, cytotoxic, genotoxic, and mutagenic potentials of pure sludge samples (WS and SS) were evaluated, as well as the association of these two sludges with soil (S), before and after the bioremediation process. In the T0 period (before undergoing bioremediation), the SS, SS + S, and SS + WS samples totally inhibited the germination of A. cepa, proving the high phytotoxic potential of these samples. For the T1 period (after 6 months of bioremediation), phytotoxicity was observed for the SS, SS + S, SS + WS, and SS + WS + S samples, but there was not a complete inhibition of germination and radicles growth, allowing the evaluation of the other parameters (cytogenotoxic and mutagenic potential). No cytotoxicity was observed for any sample, both in T0 and T1. As for the genotoxicity parameter, a significant result was observed for the pure WS sample in T0 and for all samples in T1, when compared to NC. The genotoxic alteration most found in meristematic cells exposed to treatments was of binucleated cells. Mutagenic potential was also observed for samples of WS and WS + S in T0. From this study, we can conclude that, after six months of bioremediation, despite the SS phytotoxicity being reduced, all samples were genotoxic to the A. cepa organism test.

Evaluation of Water Quality of Buritis Lake

The implementation of natural parks in cities is a current and controversial theme. Therefore, in Lake Buritis, which is a leisure area for the population of the city of Goiatuba, Goiás, Brazil, the quality of the water was analyzed, carrying out quantitative tests of the water samples at six different points between the source and the outlet of the lake that flows into the stream, Chico À Toa. Physical–chemical tests (turbidity, pH, alkalinity, electrical conductivity, color, nitrate and hardness parameters), microbiological tests for species identification, analysis of the antimicrobial susceptibility profile, metals analysis and Allium cepa test, were performed. The total coliforms number in water samples was higher than the maximum value established by Brazilian legislation, demonstrating high fecal contamination during the spring in samples from an artesian well. The bacterial diversity found was large and there were many pathogenic bacteria. The A. cepa test demonstrated a cytotoxic potential for water from the source and outlet of Buritis Lake. Statistical tests were applied to verify existing correlations between parameters. Among the analyzed data, the highest correlation was between the color and turbidity parameters and the grouping between the metals (lead, iron, cadmium and magnesium).

Catharanthus roseus potential for phyto-stabilizing metals in sewage sludge

This work evaluated the potential of Catharanthus roseus in phytoremediation of As, Ba, Cd, Cu, Cr, Ni, Pb, Se and Zn in sewage sludge-based substrates. C. roseus was cultivated for 108 days in a treatment containing sewage sludge:vermiculite (70:30%) and in the control with 100% commercial substrate. The plants cultivated in sludge showed approximately four times greater height, number of leaves and stem diameter, as well as 89% higher fresh mass than those of the control. The highest concentrations of the metals were obtained in the roots of plants grown in the sludge, and ranged from 2.04 (Cd) to 1121 mg kg^-1 (Zn). Cu, Cd and Zn had a higher bioconcentration factor than 1 in both treatments. On the other hand, the translocation factor value in the control was greater than 1 for Ba, Cd, Cu, Ni, Se and Zn. The results showed that C. roseus was efficient in the phytoremediation of the evaluated metals, in which the translocation process was progressive in the treatment that presented higher metal content.