Search Results (50)

Although the coking industry is a major polluter, it is still an important and irreplaceable industry in many countries. Wastewater from the coking industry typically contains large amounts of various hazardous substances, including phenols, cyanides, and thiocyanates; we conducted a comprehensive study on their ecotoxicity. This included five different toxicity tests with common species from different trophic levels: the bacteria Aliivibrio fischeri and Pseudomonas putida, the microalgae Chlorella sp., the duckweed Lemna minor, and the onion plant Allium cepa. These tests have rarely or never been used for these three toxicants. The results show that cyanide generally has the highest toxicity, while phenol has a relatively equal or higher toxicity than thiocyanate, depending on the test. Since no data on the joint toxic action of these three toxicants can be found in the literature, and although their joint occurrence in the aquatic environment is very likely, we performed joint toxic action analysis. The analysis was performed for binary and ternary mixtures of the toxicants using the Aliivibrio fischeri test. The concentration addition model was used as a reference model for the toxic behavior of these mixtures. The results obtained showed a synergistic deviation from the concentration addition model for combinations of phenol with cyanide and with thiocyanate, while the combination of cyanide and thiocyanate led to additive toxic behavior. Full article

Duckweeds are a family of small floating macrophytes (the Lemnaceae) that inhabit quiet freshwaters worldwide. They have long been employed to determine toxicity to higher plants in the aquatic environment, and standardized national and international protocols have been developed for this purpose using two representative species. While these protocols, which assess the growth of the leaf-like fronds of the tested duckweed, are indeed suitable and still frequently used for detecting the toxicity of water-borne substances to aquatic higher plant life, they are cumbersome and lengthy, determine endpoints rather than depict toxicity timelines, and provide no information as to the mechanisms involved in the indicated toxicity. Progress has been made in downscaling, shortening and improving the standardized assay procedures, and the use of alternative duckweed species, protocols and endpoints for detecting toxicity has been explored. Biomarkers of toxic effect have long been determined concomitantly with testing for toxicity itself, and their potential for the assessment of toxicity has recently been greatly expanded by transcriptomic, proteomic and metabolomic techniques complemented by FITR spectroscopy, transformation and genotoxicity and timescale toxicity testing. Improved modern biomarker analysis can help to both better understand the mechanisms underlying toxicity and facilitate the identification of unknown toxins. Full article

For several decades, cement production has caused concerns about CO₂ emissions. As the production of concrete has increased over the years, the fact that cement is its key component additionally raises a concern. By partially replacing cement with waste material such as biomass waste biochar, the reduction in waste and the reduction of CO₂ emissions could be addressed at the same time but raises a concern about the ecotoxicological potential of biochar-containing cementitious composites. During their use, recycling and disposal of biochar-containing mortars could pose hazardous environmental impacts due to their exposure to rain and other environmental conditions. The aim of the study was to determine the early-age mechanical properties of mortars with 5%, 10%, and 15% biochar as partial cement replacement. The environmental impact of biochar-containing mortars in terms of carbon footprint reduction and ecotoxicological potential was addressed simultaneously. The biochar used was prepared from waste wood biomass as carpentry waste wood. Results showed that added biochar caused no significant changes in flowability and fresh density of fresh mortar mixture. The strength tests revealed mortars with 5% and 10% biochar had higher 3-day flexural strength, while only mortar with 5% biochar had higher 7- and 28-day compressive strength (4% and 6%) than the conventional mortar. The X-ray diffraction (XRD) analysis detected five main crystalline phases in biochar-containing mortars. SEM-EDS showed the strong embedment of biochar particles in cement paste. Ecotoxicological assessment based on acute toxicity tests with mortar leachates using duckweed and mustard seeds showed low toxicity of leachates with the highest inhibition values around 50%. The calculations of the total CO₂-equivalent emissions for selected mortars revealed mortars with biochar as partial cement replacement had lower CO₂-equivalent emissions than the conventional mortar and can contribute to carbon footprint reduction and at the same time to natural resource conservation. Full article

Sustainability is becoming increasingly important in the world we live in, because of the rapid global population growth and climate change (drought, extreme temperature fluctuations). People in developing countries need more sustainable protein sources instead of the traditional, less sustainable meat, fish, egg, and dairy products. Alternative sources (plant-based, such as grains (wheat, rice sorghum), seeds (chia, hemp), nuts (almond, walnut), pulses (beans, lentil, pea, lupins), and leaves (duckweed), as well as mycoproteins, microalgae, and insects) can compensate for the increased demand for animal protein. In this context, our attention has been specifically focused on duckweed—which is the third most important aquatic plant after the microalgae Chlorella and Spirulina—to explore its potential for use in a variety of areas, particularly in the food industry. Duckweed has special properties: It is one of the fastest-growing plants in the world (in freshwater), multiplying its mass in two days, so it can cover a water surface quickly even in filtered sunlight (doubling its biomass in 96 hours). During this time, it converts a lot of carbon dioxide into oxygen. It is sustainable, environmentally friendly (without any pesticides), and fast growing; can be grown in indoor vertical farms and aquaculture, so it does not require land; is easy to harvest; and has a good specific protein yield. Duckweed belongs to the family Araceae, subfamily Lemnoideae, and has five genera (Lemna, Spirodela, Wolffia, Wolffiella, Landolita) containing a total of approximately 36–38 recognised species. Duckweed is gaining attention in nutrition and food sciences due to its potential as a sustainable source of protein, vitamins, minerals, and other bioactive compounds. However, there are several gaps in research specifically focused on nutrition and the bioaccessibility of its components. While some studies have analysed the variability in the nutritional composition of different duckweed species, there is a need for comprehensive research on the variability in nutrient contents across species, growth conditions, harvesting times, and geographic locations. There has been limited research on the digestibility, bioaccessibility (the proportion of nutrients that are released from the food matrix during digestion), and bioavailability (the proportion that is absorbed and utilised by the body) of nutrients in duckweed. Furthermore, more studies are needed to understand how food processing (milling, fermentation, cooking, etc.), preparation methods, and digestive physiology affect the nutritional value and bioavailability of the essential bioactive components in duckweed and in food matrices supplemented with duckweed. This could help to optimise the use of duckweed in human diets (e.g., hamburgers or pastas supplemented with duckweed) or animal feed. More research is needed on how to effectively incorporate duckweed into diverse cuisines and dietary patterns. Studies focusing on recipe development, consumer acceptance, palatability, and odour are critical. Addressing these gaps could provide valuable insights into the nutritional potential of duckweed and support its promotion as a sustainable food source, thereby contributing to food security and improved nutrition. In summary, this article covers the general knowledge of duckweed, its important nutritional values, factors that may affect their biological value, and risk factors for the human diet, while looking for technological solutions (covering traditional and novel technologies) that can be used to increase the release of the useful, health-promoting components of duckweed and, thus, their bioavailability. This article, identifying gaps in recent research, could serve as a helpful basis for related research in the future. Duckweed species with good properties could be selected by these research studies and then included in the human diet after they have been tested for food safety. Full article

The purpose of the study was to determine the mechanical and ecotoxicological properties of mortars with differently shaped recycled PET plastics as a partial natural aggregate replacement and assess its environmental impact. Different methods were used for determining mechanical properties, while ecotoxicity tests with two types of plants were performed for the assessment of the ecotoxicological potential of mortars. Results of strength tests revealed that PET in mortars increased 28-day compressive strength by up to 3% and decreased flexural strength by up to 14% compared to conventional mortar. Ultrasonic pulse velocity and dynamic modulus of elasticity were lower in PET mortars, while XRD and SEM-EDS showed fewer hydration products in PET mortars. Duckweed ecotoxicity test results revealed that frond growth inhibition values in PETS and conventional mortar leachate (100 g L⁻¹) were around 50%, while root growth inhibition values did not exceed 40%. Mustard seed germination test results revealed root growth inhibition values in both mortar leachates were lower than 20%. Ecotoxicity tests showed that conventional and PET mortar were non-toxic to duckweed in aquatic environments and non-toxic to mustard seeds in terrestrial environments. Characterization of mortar leachates showed a significant increase in chloride, Ca, Si, and Ba content as potential causes for growth inhibition of both plants. Plastic waste reduction due to the potential use of PET in mortars confirmed that plastic waste could be completely eliminated and the global consumption of primary natural resources for concrete production reduced up to 4%. Such an approach could increase mortar sustainability. Full article

Antibiotics with significant environmental toxicity, e.g., tetracyclines (TCs), are often used in large quantities worldwide, with 50–80% of the applied dose ending up in the environment. This study aimed to investigate the effects of exposure to tetracycline hydrochloride (TC) and minocycline hydrochloride (MIN) on L. minor. Our research evaluated the phytotoxicity of the TCs by analyzing plant growth and biomass and evaluating assimilation pigment levels and fluorescence. The research was extended with the ability potential of duckweed as a tool for removing TCs from water/wastewater. The results demonstrated that both TCs influenced Ir, Iy, biomass, and photosynthetic efficiency. The uptake of TC and MIN by duckweed was proportional to the concentration in the growth medium. The TC was absorbed more readily, reaching up to 8.09 mg × g⁻¹ of dry weight (DW) at the highest concentration (19.2 mg × L⁻¹), while MIN reached 6.01 mg × g⁻¹ of DW. As indicated, the consequences of the influence of TC on plants were slightly smaller, in comparison to MIN, while the plants could biosorb this drug, even at the lowest tested concentration. This study has shown that using plants for drug biosorption can be an effective standalone or complementary method for water and wastewater treatment. Full article

In this study, the ecotoxicological effects of a selected OSB material on three model plants (green freshwater algae Desmodesmus subspicatus, duckweed Lemna minor, and seeds of lettuce Lactuca sativa) were tested. A 24 h and 168 h leachate of the same OSB material was prepared. Mg, Si, Ca, K, Fe, Zn, Mn, and Na were found in the samples. Their higher residues were measured in the 168 h leachate. Biogenic elements (N, P, C) were not detected. The acute effect was relatively slow (for algae up to 26%, for duckweed up to 20%, and for lettuce seeds with stimulation up to 37%). Prolongation of the leaching time did not show any effect on the results of the plant tests. Acute toxicity for the three plant species used was slow. Full article

Agricultural systems must improve their sustainability and productivity to meet the growing global demand for food. A cost-effective and sustainable way is the development of biostimulants from plants rich in bioactive compounds. This study aimed to test an aqueous extract from Lemna minor L. (duckweed) on tomato plants at different concentrations (LE—0.1, 0.5 and 1.0%—weight/volume, w/v). Photosystem I and II activity, linear electron flow (LEF), electrochemical gradient across the thylakoid membrane (ECSt), shoot biomass production, root phenotyping, pigment and metabolite content were studied. LE improved many of these traits, with LE 0.5% being the most effective dosage. Compared to the untreated samples, LE significantly stimulated photosystems to use light energy while reducing the amount lost as heat (PhiNPQ and NPQt) or potentially toxic to chloroplasts (PhiNO). These results were supported by the improved shoot biomass production (number of leaves and fresh and dry weight) and root traits (number of tips, surface, volume and fresh and dry weight) found for LE-treated samples compared to untreated controls. Finally, the study highlighted that LE increased pigment and flavonoid contents. In conclusion, the research indicates that this species can be an effective and eco-friendly tool to stimulate beneficial responses in tomato. Full article

Dasatinib (DAS), a potent anticancer drug, has been subjected to formulation enhancements due to challenges such as significant first-pass metabolism, poor absorption, and limited oral bioavailability. To improve its release profile, DAS was embedded in a matrix of the hydrophilic polymer polyvinylpyrrolidone (PVP). Drug amorphization was induced in a planetary ball mill by solvent-free co-grinding, facilitating mechanochemical activation. This process resulted in the formation of amorphous solid dispersions (ASDs). The ASD capsules exhibited a notable enhancement in the release rate of DAS compared to capsules containing the initial drug. Given that anticancer drugs often undergo limited metabolism in the body with unchanged excretion, the ecotoxicological effect of the native form of DAS was investigated as well, considering its potential accumulation in the environment. The highest ecotoxicological effect was observed on the bacteria Vibrio fischeri, while other test organisms (bacteria Pseudomonas putida, microalgae Chlorella sp., and duckweed Lemna minor) exhibited negligible effects. The enhanced drug release not only contributes to improved oral absorption but also has the potential to reduce the proportion of DAS that enters the environment through human excretion. This comprehensive approach highlights the significance of integrating advances in drug development while considering its environmental implications. Full article

Pollutants accumulate in aquatic habitats due to mining activities. The duckweed family includes water plants such as Lemna gibba and Lemna minor, which are tiny, delicate, free-floating aquatic plants. L. minor and L. gibba were used in this study to examine the accumulation capacities of Mo⁴⁺, Pb⁺⁺, and Cu⁺⁺ in acidic fluids from copper mining. Two reactors were assigned to L. gibba and L. minor, respectively. These plants and the reactor water were gathered daily for 8 days. Acid mine water pH, temperature, and electric conductivity were also tested daily. L. gibba and L. minor were cleaned, dehydrated, and burned in a drying oven for a whole day at 300 °C. ICP-MS (inductively coupled plasma mass spectroscopy) was used to determine the Mo⁴⁺, Pb⁺⁺, and Cu⁺⁺ content of the plant and water samples. The Mo, Pb, and Cu concentrations in the copper mining acidic fluids were 30 ± 4, 260 ± 12, and 15,535 ± 322 μg L⁻¹, respectively. Regarding Mo, Pb, and Cu extraction from copper mining acidic fluids, L. gibba and L. minor performed more efficiently than control samples, gathering 29 and 177 times more Mo, 30 and 109 times more Pb, and 495 and 1150 times more Cu, respectively. Considering these findings, L. gibba and L. minor are good plants for rehabilitating polluted waters and can efficiently remove Mo, Pb, and Cu from acid mine fluids. Full article

In this study, we exposed a commonly used duckweed species—Lemna gibba L.—to twelve environmentally relevant metals and metalloids under laboratory conditions. The phytotoxic effects were evaluated in a multi-well-plate-based experimental setup by means of the chlorophyll fluorescence imaging method. This technique allowed the simultaneous measuring of the growth and photosynthetic parameters in the same samples. The inhibition of relative growth rates (based on frond number and area) and photochemical efficiency (F_v/F_o and Y(II)) were both calculated from the obtained chlorophyll fluorescence images. In the applied test system, growth-inhibition-based phytotoxicity endpoints proved to be more sensitive than chlorophyll-fluorescence-based ones. Frond area growth inhibition was the most responsive parameter with a median EC₅₀ of 1.75 mg L⁻¹, while F_v/F_o, the more responsive chlorophyll-fluorescence-based endpoint, resulted in a 5.34 mg L⁻¹ median EC₅₀ for the tested metals. Ag (EC₅₀ 0.005–1.27 mg L⁻¹), Hg (EC₅₀ 0.24–4.87 mg L⁻¹) and Cu (EC₅₀ 0.37–1.86 mg L⁻¹) were the most toxic elements among the tested ones, while As(V) (EC₅₀ 47.15–132.18 mg L⁻¹), Cr(III) (EC₅₀ 6.22–19.92 mg L⁻¹), Se(VI) (EC₅₀ 1.73–10.39 mg L⁻¹) and Zn (EC₅₀ 3.88–350.56 mg L⁻¹) were the least toxic ones. The results highlighted that multi-well-plate-based duckweed phytotoxicity assays may reduce space, time and sample volume requirements compared to the standard duckweed growth inhibition tests. These benefits, however, come with lowered test sensitivity. Our multi-well-plate-based test setup resulted in considerably higher median EC₅₀ (3.21 mg L⁻¹) for frond-number-based growth inhibition than the 0.683 mg L⁻¹ median EC₅₀ derived from corresponding data from the literature with standardized Lemna-tests. Under strong acute phytotoxicity, frond parts with impaired photochemical functionality may become undetectable by chlorophyll fluorometers. Consequently, the plant parts that are still detectable display a virtually higher average photosynthetic performance, leading to an underestimation of phytotoxicity. Nevertheless, multi-well-plate-based duckweed phytotoxicity assays, combined with chlorophyll fluorescence imaging, offer definite advantages in the rapid screening of large sample series or multiple species/clones. As chlorophyll fluorescence images provide information both on the photochemical performance of the test plants and their morphology, a joint analysis of the two endpoint groups is recommended in multi-well-plate-based duckweed phytotoxicity assays to maximize the information gained from the tests. Full article

Intensive poultry production may result in substantial emissions of pollutants into the environment, including pharmaceuticals and other chemicals used in poultry farming. The objective of this study was to verify the presence of ciprofloxacin, enrofloxacin, carbamazepine, metoclopramide, trimethoprim, diflufenican, flufenacet, and p,p′-DDE in soil and water in the immediate vicinity of a poultry manure heap. The influence of soil contaminants on the growth and selected physiological parameters of seed peas and common duckweed (as indicator plants) was tested. It has been proven that the cultivation of pea plants on soil coming from the close proximity of a heap of manure results in a deterioration of both morphological parameters (root length, shoot length) and physiological parameters (chlorophyll absorption, aminolevulinic acid dehydrogenase (ALAD) activity, aminolevulinic acid (ALA) content, lipid peroxidation, mitochondrial damage or production of HSP70 proteins). Similarly, water extracts from cultivated soils had a significant effect on duckweed, and it was found that contaminant leachates are indeed detectable in soil, groundwater, and deep water. Special attention should, therefore, be paid to the location, methods of storage, and use of poultry fertilizer. Full article

The identification of natural and environmentally friendly pesticides is a key area of interest for the agrochemical industry, with many potentially active compounds being sourced from numerous plant species. In this study, we report the bioassay-guided isolation and identification of phytotoxic and antifungal compounds from the ethyl acetate extract of Helietta parvifolia stems. We identified eight compounds, consisting of two coumarins and six alkaloids. Among these, a new alkaloid, 2-hydroxy-3,6,7-trimethoxyquinoline-4-carbaldehyde (6), was elucidated, along with seven known compounds. The phytotoxicity of purified compounds was evaluated, and chalepin (4) was active against Agrostis stolonifera at 1 mM with 50% inhibition of seed germination and it reduced Lemna pausicotata (duckweed) growth by 50% (IC₅₀) at 168 μM. Additionally, we evaluated the antifungal activity against the fungal plant pathogen Colletotrichum fragariae using a thin-layer chromatography bioautography assay, which revealed that three isolated furoquinoline alkaloids (flindersiamine (3), kokusagenine (7), and maculine (8)) among the isolated compounds had the strongest inhibitory effects on the growth of C. fragariae at all tested concentrations. Our results indicate that these active natural compounds, i.e., (3), (4), (7), and (8), could be scaffolds for the production of more active pesticides with better physicochemical properties. Full article

Biosensors based on an oxygen electrode, a mediator electrode, and a mediator microbial biofuel cell (MFC) using the bacteria Gluconobacter oxydans B-1280 were formed and tested to determine the integral toxicity. G. oxydans bacteria exhibited high sensitivity to the toxic effects of phenol, 2,4-dinitrophenol, salicylic and trichloroacetic acid, and a number of heavy metal ions. The system “G. oxydans bacteria–ferrocene–graphite-paste electrode” was superior in sensitivity to biosensors formed using an oxygen electrode and MFC, in particular regarding heavy metal ions (EC₅₀ of Cr³⁺, Mn^2+, and Cd²⁺ was 0.8 mg/dm³, 0.3 mg/dm³ and 1.6 mg/dm³, respectively). It was determined that the period of stable functioning of electrochemical systems during measurements was reduced by half (from 30 to 15 days) due to changes in the enzyme system of microbial cells when exposed to toxicants. Samples of the products made from polymeric materials were analyzed using developed biosensor systems and standard biotesting methods based on inhibiting the growth of duckweed Lemna minor, reducing the motility of bull sperm, and quenching the luminescence of the commercial test system “Ecolum”. The developed bioelectrocatalytic systems were comparable in sensitivity to commercial biosensors, which made it possible to correlate the results and identify, by all methods, a highly toxic sample containing diphenylmethane-4,4′-diisocyanate according to GC-MS data. Full article

Aquatic environment are often contaminated with heavy metals from various industrial sources. However, physicochemical techniques for pollutant detection are limited, thus prompting the need for additional bioassays. We investigated the use of greater duckweed (Spirodela polyrhiza) as a bioindicator of metal pollution. We exposed S. polyrhiza to four pollutants (namely, silver, cadmium, copper, and chromium) and assessed metal toxicity by measuring its frond area and the length of its regrown roots. The plant displayed significant differences in both frond size and root growth in response to the four metals. Silver was the most toxic (EC₅₀ = 23 µg L⁻¹) while copper the least (EC₅₀ = 365–607 µg L⁻¹). Direct comparisons of metal sensitivity and the reliability of the two endpoint assays showed that root growth was more sensitive (lower in terms of 50% effective concentration) to chromium, cadmium, and copper, and was more reliable (lower in terms of coefficient of variation) than those for frond area. Compared to conventional Lemna-based tests, the S. polyrhiza test is easier to perform (requiring only one 24-well plate, 3 mL of medium and a 72-h exposure). Moreover, it does not require livestock cultivation/maintenance, making it more suitable for repeated measurements. Measurements of S. polyrhiza root length may be suitable for assessment when copper and chromium in municipal and industrial wastewater exceed the environmentally permissible levels. Full article