Agricultural potential and safety assessment of biochar obtained from river biomass.

The paper presents results from seed germination and root elongation tests for the evaluation of Lake Orta sediment contamination. The protocol for this test was developed after a literature survey and careful investigation of the proper conditions for obtaining the germination of commercially available seeds of several plants. Cucumis sativus, Lactuca sativa, and Lepidium sativum were finally chosen and used to detect the phytotoxicity of both liquid and solid phases of Lake Orta sediments. To assess whether exchange at the water – sediment interface could represent a hazard for the environment and the actual bioavailability of the toxicants present into the sediments, the phytotoxicity of samples collected in 1992, 1994, 1996, 1997, and 1998 from selected stations was tested on seeds of three different plant species (Lactuca sativa, Lepidium sativum and Cucumis sativus). The obtained results allow drawing distribution maps of the germination index, which confirm the persistence of toxic effects. However, the lake seems to positively respond to the restoration treatment, since the more contaminated layers of sediments are presently buried under less toxic sediments.

Combining genotoxicity/mutagenicity tests and physico-chemical methodologies can be useful for determining the potential genotoxic contaminants in soil samples. The aim of our study was to evaluate the genotoxicity of soil by applying an integrated physico-chemical-biological approach. Soil samples were collected at six sampling points in a Slovenian industrial and agricultural region where contamination by heavy metals and sulphur dioxide (SO(2)) are primarily caused by a nearby power plant. The in vitro alkaline version of the comet assay on water soil leachates was performed with Caco-2 and HepG2 cells. A parallel genotoxicity evaluation of the samples was performed by Ames test using Salmonella typhimurium and the Tradescantia micronucleus test. Pedological analyses, heavy metal content determination, and different physico-chemical analyses, were also performed utilizing standard methodology. Water leachates of soil samples were prepared according to standard methods. Since only a battery of biotests with prokaryotic and eukaryotic organisms or cells can accurately estimate the effects of (geno)toxicants in soil samples and water soil leachates, a combination of three bioassays, with cells or organisms belonging to different trophic levels, was used. Genotoxicity of all six water soil leachates was proven by the comet assay on both human cell lines, however no positive results were detected by bacterial assay, Ames test. The Tradescantia micronucleus assay showed increase in micronuclei formation for three samples. According to these results we can assume that the comet assay was the most sensitive assay, followed by the micronucleus test. The Ames test does not appear to be sensitive enough for water soil leachates genotoxicity evaluations where heavy metal contamination is anticipated.

Six commercial quinones (2,5 - dihydroxy-1,4-benzoquinone [1], camphorquinone [2], phenantrequinone [3], anthrarufin [4], sodium sulfonate anthraquinone [5] and lapachol [6]) were tested as for their phytotoxic potential. The compounds were tested on Sorghum bicolor , Cucumis sativus , and Desmodium tortuosum cultivated in washed sand in Petri dishes and on Lactuca sativa , Cucumis sativus , Desmodium tortuosum , Hyptis suaveolens and Euphorbia heterophylla , cultivated in pots, containing washed sand, for 20 days. In the tests in Petri dishes, quinone 2 caused a little inhibition (25.62%) to the development of S. bicolor . Quinones 1, 2, 3 and 5 caused a very little effect on C. sativus . None of the tested quinones caused a significant inhibition effect to D. tortuosum . In the bioassays in pots, quinones 2, 3, 4 and 6 caused a significant inhibition (9.52 to 71.43%) to the root system of H. suaveolens

Soil invertebrate avoidance behavior identifies petroleum hydrocarbon contaminated soils toxic to sensitive plant species.

Salad Crops: Leaf-Type Crops

Indium

Anaerobic digestate is a by-product from the biogas production which can be applied as replacement for mineral fertilizers. But digestate has both phytostimulating and phytotoxic effects on plants. Fertilizers toxicity and phytotoxicity should be measured to preserve the environment. The phytotoxicity of digestate from anaerobic digestion of swine manure was evaluated using several official protocols. Germination toxicity was tested on Pisum sativum L. and Lepidium sativum L., roots elongation on Hordeum vulgare L. and shoots elongation on Lactuca sativa L. To determine digestate growth toxicity, pot experiments were performed on two Solanum lycopersicum L. cvs. Digestate dilutions ranging from 5 to 30 % were tested in the different assays. Standard protocols were applied to non-standard species: Cichorium endivia L. (shoots elongation) and two Capsicum annuum L. cvs (pot trials). Digestate concentrations stimulating germination and early life stages were between 2 and 3 %. Pot trials suggested that during more advanced growth stages, digestate can be applied at 20–30 %. The main finding was that to minimize digestate phytotoxicity, direct contact with germinating seeds or young plants should be avoided. During plants late growth, digestate administration might be increased carefully to minimize salinity and ammonia excess. Soil samples from the pot trials were analysed at the starting, mid- and final experimental stages. Conclusion was that digestate utilization may have also a soil liming effect, increasing electric conductivity, pH and contrasting soil acidification.

Plant catalases exhibit spatial and temporal distribution of their activity. Moreover, except from the typical monofunctional catalase, a bifunctional catalase-peroxidase has been reported. The aim of this study was to investigate whether the leaf and root catalases from six different plant species (Lactuca sativa, Cichorium endivia, Apium graveolens, Petroselinum crispum, Lycopersicon esculentum, and Solanum melongena) correspond to the monofunctional or the bifunctional type based on their sensitivity to the inhibitor 3-amino-1,2,4-triazole (3-AT). The leaf catalases from all species seem to be monofunctional since they are very sensitive to 3-AT. On the other hand, the root enzymes from Lactuca sativa, Cichorium endivia, Lycopersicon esculentum, and Solanum melongena seem to be bifunctional catalase-peroxidases, considering that they are relatively insensitive to 3-AT, whereas the catalases from Apium graveolens and Petroselinum crispum display the same monofunctional characteristics as the leaves’ enzymes. The leaf catalase activity is usually higher (Lactuca sativa, Petroselinum crispum, and Solanum melongena) or similar (Cichorium endivia and Apium graveolens) to the root one, except for the enzyme from Lycopersicon esculentum, while in all plant species the leaf protein concentration is significantly higher than the root protein concentration. These results suggest that there are differences between leaf and root catalases—differences that may correspond to their physiological role.

<i>Tomato spotted wilt tospovirus</i>, <i>Impatiens necrotic spot tospovirus</i> and <i>Watermelon silver mottle tospovirus</i>

Carbon dioxide as a carrier gas and mixed feedstock pyrolysis decreased toxicity of sewage sludge biochar

Effects of garden and water cress juices and their constituents, benzyl and phenethyl isothiocyanates, towards benzo(a)pyrene-induced DNA damage: a model study with the single cell gel electrophoresis/Hep G2 assay

Toxicological potential of 2-alkylcyclobutanones – specific radiolytic products in irradiated fat-containing food – in bacteria and human cell lines

Zinc (Zn) is an essential micronutrient for plants and an important component for maintaining soil quality. Commonly found in the soil due to anthropogenic activities, such as industrialization and application of organic waste as fertilizers, in high concentrations, Zn may induce soil toxicity, affecting important communities, such as edaphic fauna. Despite its high concentrations found in the environment, Zn bioavailability can be affected by the type of soil, organic matter content and pH. In this work, Zn had its toxicity evaluated in a natural tropical soil, sampled in São Paulo-Brazil, for two soil invertebrates (Folsomia candida, Enchytraeus crypticus) and two seeds (Lactuca sativa and Phaseolus vulgaris), through ecotoxicological tests. The invertebrate E. crypticus was exposed to Zn concentrations of 10.0 (T1); 100.0 (T2); 150.0 (T3); 200.0 (T4); 400.0 (T5) mg Zn kg-1 of dry soil, while F. candida, L. sativa and P. vulgaris were exposed to Zn concentrations of 100.0; 200.0; 400.0; 800.0 (t6); 1600.0 (t7); and 2000.0 (t8) mg Zn kg-1 of dry soil. The outcome evaluated were seed germination, for L. sativa and P. vulgaris, and reproduction, for F. candida and E. crypticus. The EC50 obtained for E. crypticus, F. candida, L. sativa, and P. vulgaris were 261.5, 1089.7, 898.5, and 954.5mg Zn kg-1 of dry soil, respectively, being E. crypticus the most sensitive organism, and only at the highest Zn's concentrations the organisms' reproduction and seeds' germination showed a statistically significant inhibitory effect (p < 0.05). Therefore, this work's results showed that Zn does not present significant toxicity for the tested soil organisms and seeds and that at 100mg Zn kg-1 of dry soil it can be beneficial to F. candida and E. crypticus' reproduction and L. sativa's germination. These results imply that the presence of Zn in low concentrations, both in soil and biofertilizers, such as sewage sludge, not only is not a concern, but it can even benefit certain crops and functions of edaphic organisms, which may contribute to the engagement of sustainable agricultural practices and the quest for food security.

Titanium dioxide nanoparticles (TiO2-NPs) are being used increasingly for various industrial and consumer products, including cosmetics and sunscreens because of their photoactive properties. Therefore, the toxicity of TiO2-NPs needs to be thoroughly understood. In the present study, the genotoxicity of 10nm uncoated sphere TiO2-NPs with an anatase crystalline structure, which has been well characterized in a previous study, was assessed using the Salmonella reverse mutation assay (Ames test) and the single-cell gel electrophoresis (Comet) assay. For the Ames test, Salmonella strains TA102, TA100, TA1537, TA98 and TA1535 were preincubated with eight different concentrations of the TiO2-NPs for 4 h at 37 °C, ranging from 0 to 4915.2 µg per plate. No mutation induction was found. Analyses with transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) showed that the TiO2-NPs were not able to enter the bacterial cell. For the Comet assay, TK6 cells were treated with 0-200 µg ml(-1) TiO2-NPs for 24 h at 37 °C to detect DNA damage. Although the TK6 cells did take up TiO2-NPs, no significant induction of DNA breakage or oxidative DNA damage was observed in the treated cells using the standard alkaline Comet assay and the endonuclease III (EndoIII) and human 8-hydroxyguanine DNA-glycosylase (hOGG1)-modified Comet assay, respectively. These results suggest that TiO2-NPs are not genotoxic under the conditions of the Ames test and Comet assay.

Organic biodegradable waste composes a fair part of farm and vital activity waste. The disposal of this waste in municipal waste landfills pollutes the environment and soil. Therefore, the European Union and other countries look for alternatives to manage biodegraded waste. This paper seeks to analyse the properties of sludge that forms in the sewage treatment plants of the acid casein production, examines experience in managing and applying sludge. The results of an experiment show that sewage sludge from the acid casein production is suitable as a soil fertilizer for growing lettuce (Lactuca sativa L.) and garden cress (Lepidium sativum L.). After soil was fertilized with this sludge, the germination of lettuce and garden cress as well as the biomass of experimental alimentary plants increased. A suitable ratio of soil and sludge mixture was determined (for lettuce ‐ 1:1, for garden cress ‐ 3:1). Potassium sulphate which was added to a soil‐sludge mixture improved the values of fertility parame...