Concentrations Of Toxic Heavy Metals Research Articles

Potential of Selected Species of Spiraea L. for Phytoremediation of Heavy Metals from Soils of Urban Areas

Four taxa of Spiraea were selected for this study: S. × cinerea Zabel ‘Grefsheim’, S. nipponica Maxim. ‘Snowmound’, S. splendens É. N. Baumann ex K. Koch and S. × vanhouttei (Briot) Carrière growing for a minimum of 5 years along heavily trafficked traffic routes. This study included the genus Spiraea due to its popularity in horticultural practice (commercial availability, widespread in urban environments). In addition, the use of ornamental shrubs for phytoremediation in urban green spaces effectively combines the aesthetic needs of residents with those of caring for the urban environment. This study was conducted in Poznań (population 550,000, the fifth largest city in Poland). Soils and foliage were examined in spring and autumn. Soil pH and specific electrolytic conductivity (EC) were determined. The content of micronutrients (Cu, Fe, Mn, Ni, Zn) and toxic heavy metals (Cd, Cr, Pb) in soil dry matter and leaves was determined. The uptake capacity of bioavailable forms of heavy metals by Spiraea from the soil was analyzed by determining the bioconcentration factor (BCF). It was found that the studied taxa meet the basic requirements for plants used for soil phytoremediation processes, especially for chromium phytoextraction. The degree of salinity of the tested soils did not pose a threat to the shrubs growing there, and most of the sites, despite the alkaline reaction, are suitable for their cultivation. S. × cinerea and S. × vanhouttei have BCFs for lead <1. The remaining taxa are characterized by strong concentrations of all analyzed elements. A particularly high BCF, above 10, was recorded for chromium and high for manganese and nickel.

Metal contamination in mangrove tissues, seeds, and associated sediments from the Vattanam mangrove forest of Palk Bay, southeastern India: An ecological risk assessment

In the present work, the concentrations of toxic heavy metals in mangrove sediments, mangrove leaves, and seeds collected from five stations in the Vattanam mangrove of Palk Bay, southeastern India, as well as the effects of the monsoon season on toxic heavy metals concentrations were determined. The concentrations were 17.5 μg/g for zinc (Zn), 9.11 μg/g for copper (Cu), and 6.03 μg/g for lead (Pb) in sediments; 10.71 μg/g (Zn) and 8.94 μg/g (Cu) in mangrove leaves; and 26.24 μg/g (Zn) and 17.01 μg/g (Cu) in mangrove seeds. At all sampling stations, the Cd concentration was below the limit of detection. These mangroves seem to have adapted successfully to their environment given their selective intake of only essential metals (Cu and Zn) and the restricted movement of non-essential metals (Cd and Pb). The concentrations of metals were below the maximum residual limits regulated by national and international standard limits.

Metal tolerance of Río Tinto fungi.

Southwest Spain's Río Tinto is a stressful acidic microbial habitat with a noticeably high concentration of toxic heavy metals. Nevertheless, it has an unexpected degree of eukaryotic diversity in its basin, with a high diversity of fungal saprotrophs. Although some studies on the eukaryotic diversity in Rio Tinto have been published, none of them used molecular methodologies to describe the fungal diversity and taxonomic affiliations that emerge along the river in different seasons. The aim of the present study was to isolate and describe the seasonal diversity of the fungal community in the Río Tinto basin and its correlation with the physicochemical parameters existing along the river's course. The taxonomic affiliation of 359 fungal isolates, based on the complete internal transcribed spacer DNA sequences, revealed a high degree of diversity, identifying species belonging primarily to the phylum Ascomycota, but representatives of the Basidiomycota and Mucoromycota phyla were also present. In total, 40 representative isolates along the river were evaluated for their tolerance to toxic heavy metals. Some of the isolates were able to grow in the presence of 1000 mM of Cu2+, 750 mM of As5+ and Cd2+, and 100 mM of Co2+, Ni2+, and Pb2+.

Toxic heavy metals content in different agrochemicals available in markets of Bangladesh and their loads to the agricultural lands.

A study was conducted to determine the concentration of toxic heavy metals in various agrochemicals available in Bangladesh and to assess the burden of these metals on agricultural soils. An atomic absorption spectrophotometer (AAS) was used to measure the content of 4 toxic metals (Cd, Pb, Cr, and Ni) in the aqueous extract of various agrochemicals. There were significant differences in the amounts of Cd, Pb, Cr, and Ni in different brands of insecticides (mean < 0.01, 3.16, 17.32, and 47.33 µgg-1), fungicides (mean 12.42, 10.19, 9.63, and 243.34 µgg-1), phosphatic fertilizers (mean 25.43, < 0.01, 206.33, and 210.69 µgg-1), micronutrient fertilizers (mean 0.68, < 0.01, 43.43, and 65.79 µgg-1), and plant hormones (mean < 0.01, < 0.01, 9.90, and 43.08 µgg-1). The concentrations of Cd and Ni were on anaverage higher in phosphatic fertilizers, which exceeded the maximum acceptable limit of fertilizers in Bangladesh by 2.5 and 4.2 times, respectively. The study also revealed that the burden of toxic heavy metals from agrochemicals on farm soils was in the following order: phosphatic fertilizers > fungicides > micronutrient fertilizers > plant hormones > insecticides. Among the toxic heavy metals, Ni posed the highest burden on Bangladeshi farm soils due to a single application of different agrochemicals in a year. The average total burden of each metal in the soils of Bangladesh showed a decreasing trend in the order of Ni > Cr > Cd > Pb, resulting in a total metal burden of 22.88gyear-1ha-1. Finally, the study recommended that certification about the content of metals be made mandatory for agrochemical manufacturing firms to ensure that their products entering in Bangladeshi markets are free from toxic metals.

Analysis of Fibropapillomatosis in Roe Deer (Capreolus capreolus) Confirms High Content of Heavy Metals.

In recent decades, there has been an increase in European wild ungulate populations, often associated with a decline in health and spread of disease. This is true for the roe deer (Capreolus capreolus), the most common European cervid, with populations apparently affected by fibropapillomatosis, an increasingly common cancer. To date, however, there has been little research into this disease, thus many interactions remain unclear and descriptions of tumour composition are poorly validated. The main aim of the present study was to evaluate the presence and concentration of toxic heavy metals in roe deer skin tumours. Our results confirmed the presence of virtually all the metals tested for, i.e., Pb, Hg, Cd, As, Cr, Mn, Al, Co, Cu, Ni, Se, Zn, and Fe, with the highest average concentrations found for Cr (0.99 mg/kg-1 ± 2.23 SD), Cd (0.03 mg/kg-1 ± 0.03 SD), and Hg (0.02 mg/kg-1 ± 0.02 SD), exceeding FAO limits for meat from slaughtered animals. We also observed a significant positive relationship between heavy metal concentration and age, especially for Pb, As, Hg, Mn, Se, Al, Zn, and Ni. Our findings provide a strong baseline for further research on the impact of fibropapillomatosis, not only on the welfare and health status of game but also on the final consumer of venison, which in many respects is regarded as a high-quality, ecological, and renewable wild resource. While deer with this disease are not considered qualitatively or medically defective, they could represent a potential reservoir of substances toxic to humans and could affect substance levels in adjacent tissues or the animal as a whole.

Hybrid machine learning approach integrating GMDH and SVR for heavy metal concentration prediction in dust samples.

In agricultural regions prone to dust storms, heavy metal contamination of soil and crops from airborne particulates poses significant risks to food safety and public health. This study has assessed the potential of machine learning models for predicting concentrations of toxic heavy metals like arsenic, chromium, and lead in dust from the agricultural Sistan region of southeastern Iran. This region experiences frequent dust storms mobilizing particulates from local dried lakes onto agricultural lands. The metals including nickel, copper, magnesium, cobalt, zinc, chromium, arsenic, and lead were measured in summer dust samples during 2012-2018 across 15 stations. Two hybrid models were developed combining group method of data handling (GMDH) and support vector regression (SVR) machine learning with harmony search optimization (H) so as to predict toxic metals arsenic, chromium, and lead using nickel, copper, magnesium, cobalt, and zinc inputs. Standard error maps were uncertainty higher in southern and western areas, and they are most impacted by dust storms. Results demonstrated that the hybrid GMDH + H and SVR + H models improved the accuracy of individual GMDH and SVR models in predicting heavy metals. The GMDH + H model performed the best for the lead with an agreement index (d-index) of 0.98, root mean square error (RMSE) of 2.87ppm, normalized RMSE (NRMSE) of 0.12, and coefficient of determination (RR) of 0.96. The SVR + H model showed the highest accuracy for arsenic and chromium, obtaining d-index 0.96, RMSE 0.47ppm, NRMSE 0.09, and RR 0.92 for arsenic, and d-index 0.96, RMSE 11.24ppm, NRMSE 0.16, and RR 0.93 for chromium. Taylor's diagram and heatmap analysis confirmed the superiority of the hybrid techniques. This work demonstrates the utility of state-of-the-art computing for addressing complex environmental health challenges.

Evaluation of toxic heavy metal content in marketed Ayurvedic decoctions using closed vessel microwave digestion in ICPMS

Evaluation of toxic heavy metal content in marketed Ayurvedic decoctions using closed vessel microwave digestion in ICPMS

Determination of potentially toxic heavy metals in selected wood treatment sites in Uasin Gishu County and their associated health concerns

One of the monumental environmental and public health concerns of our time lies in the use of toxic preservatives in wood treatment plants. In this investigation, we report the results of potentially toxic heavy metals from wood treatment plants in Uasin Gishu County. A 20 g ground and sieved soil sample from each sampling site Cheplaskei (CK), Outspan (OS) and Sukunanga (SK) was weighed and treated with 0.5 M nitric acid for 2 h. The sample was then analyzed for potentially toxic metals using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The statistical treatment of the data was done using Principal component analysis (PCA) and Pearson’s correlation. The highest concentration of copper was observed at SK, which contributed approximately 37% of all the potentially toxic heavy metal content analyzed, whereas the concentration of lead was found to be about 33% of the total heavy metal content analyzed at the same sampling site. Furthermore, the most abundant metal in the sampled sites is manganese, which was found to be 390.0 ± 8.63, 279.0 ± 8.05and 44.5 ± 2.95 ppm in OS, CK, and SK, respectively. PCA showed that the heavy metals in the sample sites originated from two independent sources—natural and anthropogenic. Evidently from the concentration profile data, all the potentially toxic heavy metals had concentrations above the World Health Organization (WHO) acceptable limits, although, based on the contamination factors determined, the wood treatment sites are less polluted; however, there is need for regular monitoring to ensure adherence to proper public and environmental health practices.

Heavy metals in wastewater and fish collected from waste stabilization pond and human health risks in southwestern Ethiopia

IntroductionThis study aimed to measure the concentration of toxic heavy metals in wastewater samples and Nile tilapia (Oreochromis niloticus) species inhabiting wastewater (waste stabilization ponds) and evaluate their safety as a food source in southwestern Ethiopia. For this purpose, toxic metals like lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) in wastewater samples and fish tissues (muscle, gill, and liver) were independently examined.MethodsA laboratory-based cross-sectional study was performed to ascertain the levels of Pb, Cd, As, and Hg in the fish tissues of O. niloticus and wastewater samples. Heavy metal levels were analyzed by microplasma atomic emission spectrometry (Agilent 4210 MP-AES) and hydrogen-generated atomic absorption spectrometry (HGAAS, novAA 400P, Germany).ResultsHeavy metal concentrations were measured in the following decreasing order (µg L−1): Cd &amp;gt; Pb &amp;gt; As &amp;gt; Hg in facultative and maturation ponds, with Cd (27.66 µg L−1) having the highest concentration and Hg (0.349 µg L−1) having the lowest concentration. Among the heavy metals detected in the wastewater samples, Hg showed a statistically significant difference between the sampling points (p = 0.023). The maximum metal concentration was measured for Pb (0.35 mg kg−1) and Cd (0.24 mg kg−1) in the muscle tissue of O. niloticus. The value of arsenic (0.02 mg kg−1) detected in fish edible muscles exceeded the FAO/WHO maximum permissible limit (MPL = 0.01) for human consumption. The carcinogenic and non-carcinogenic health risks of consuming fish due to trace metals were relatively low and posed fewer potential threats to human health. According to this finding, children were more susceptible to heavy metal exposure than adults.ConclusionDue to the high quantities of these harmful heavy metals, wastewater from oxidation ponds should not be used for fishing to avoid bioaccumulation. The target carcinogenic risk (TR) and target hazard quotient (THQ) indicated that all heavy metals were below the safe threshold. This research will provide a baseline for monitoring trace metals in various edible aquatic creatures and for future research in artificial habitats and regulatory considerations.

Standardization and Quality Assessment of Drakshavaleha: Insights from Three Marketed Brands

Drakshavaleha, a traditional Ayurvedic formulation, is widely used for its therapeutic benefits in treating respiratory and digestive ailments. This study aims to standardize and evaluate the quality of Drakshavaleha from three different marketed brands through a comprehensive assessment of their physicochemical and pharmacognostical properties, alongside an estimation of toxic heavy metals content and microbial contamination, and phytochemical profiles. Materials and Methods: Three brands of Drakshavaleha were meticulously assessed through a range of tests, including organoleptic analysis, physicochemical evaluations, heavy metal content analysis, microbial contamination assessments, and qualitative phytochemical screenings. Standardized protocols and methodologies from pharmacopoeias were used for all evaluations to ensure reliable and consistent results. Results and Discussion: The findings indicated notable variations in the evaluation parameters of the different brands. Physicochemical and Pharmaceutical analysis revealed disparities in pH levels and total reducing sugar levels. Heavy metal testing and microbial contamination levels were within acceptable ranges for all samples. The qualitative phytochemical screening identified differences in the concentration of key active ingredients, potentially impacting therapeutic efficacy. Conclusion: This study underscores the importance of standardization in maintaining the safety and efficacy of Ayurvedic formulations. By identifying variations in quality and safety parameters, it provides critical insights for manufacturers to improve their production processes. Ultimately, this research advocates for enhanced quality assurance practices to uphold the integrity of Ayurvedic medicine in the global market.

Arsenite tolerance and removal potential of the indigenous halophilic bacterium, Halomonas elongata SEK2.

The indigenous halophilic arsenite-resistant bacterium Halomonas elongata strain SEK2 isolated from the high saline soil of Malek Mohammad hole, Lut Desert, Iran, could tolerate high concentrations of arsenate (As5+) and arsenite (As3+) up to 800 and 40 mM in the SW-10 agar medium, respectively. The isolated strain was able to tolerate considerable concentrations of other toxic heavy metals and oxyanions, including Cadmium (Cd2+), Chromate (Cr6+), lead (Pb2+), and selenite (Se4+), regarding the high salinity of the culture media (with a total salt concentration of 10% (w/v)), the tolerance potential of the isolate SEK2 was unprecedented. The bioremoval potential of the isolate SEK2 was examined through the Silver diethyldithiocarbamate (SDDC) method and demonstrated that the strain SEK2 could remove 60% of arsenite from arsenite-containing growth medium after 48 h of incubation without converting it to arsenate. The arsenite adsorption or uptake by the halophilic bacterium was investigated and substantiated through Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), and Energy Dispersive X-ray (EDX) analyses. Furthermore, Transmission electron microscope (TEM) analysis revealed ultra-structural alterations in the presence of arsenite that could be attributed to intracellular accumulation of arsenite by the bacterial cell. Genome sequencing analysis revealed the presence of arsenite resistance as well as other heavy metals/oxyanion resistance genes in the genome of this bacterial strain. Therefore, Halomonas elongata strain SEK2 was identified as an arsenite-resistant halophilic bacterium for the first time that could be used for arsenite bioremediation in saline arsenite-polluted environments.

Modulatory Role of Biochar Properties and Environmental Risk of Heavy Metals by Co-Pyrolysis of Fenton Sludge and Biochemical Sludge.

Recent studies have reported that Fenton sludge and biochemical sludge contain high concentrations of toxic substances and heavy metals (HMs), whereas improper treatment can pose serious threats to environmental safety. Pyrolysis is considered an efficient technology to replace conventional sludge treatment. This study investigated the pyrolysis and kinetic processes of Fenton sludge and biochemical sludge, revealed the physicochemical properties of sludge biochar, and highlighted the role of co-pyrolysis in sludge immobilization of HMs and environmental risks. Results showed that Fenton sludge and biochemical sludge underwent three stages of weight loss during individual pyrolysis and co-pyrolysis, especially co-pyrolysis, which increased the rate of sludge pyrolysis and reduced the decomposition temperature. The kinetic reaction indicated that the activation energies of Fenton sludge, biochemical sludge, and mixed sludge were 11.59 kJ/mol, 8.50 kJ/mol, and 7.11 kJ/mol, respectively. Notably, co-pyrolysis reduced the activation energy of reactions and changed the specific surface area and functional group properties of the biochar produced from sludge. Meanwhile, co-pyrolysis effectively immobilized Cu, Pb, and Zn, increased the proportion of metals in oxidizable and residual states, and mitigated the environmental risks of HMs in sludge. This study provided new insights into the co-pyrolysis properties of sludge biochar and the risk assessment of HMs.

Bacterial diversity and chemical ecology of natural product-producing bacteria from Great Salt Lake sediment.

Great Salt Lake (GSL), located northwest of Salt Lake City, UT, is the largest terminal lake in the USA. While the average salinity of seawater is ~3.3%, the salinity in GSL ranges between 5% and 28%. In addition to being a hypersaline environment, GSL also contains toxic concentrations of heavy metals, such as arsenic, mercury, and lead. The extreme environment of GSL makes it an intriguing subject of study, both for its unique microbiome and its potential to harbor novel natural product-producing bacteria, which could be used as resources for the discovery of biologically active compounds. Though work has been done to survey and catalog bacteria found in GSL, the Lake's microbiome is largely unexplored, and little to no work has been done to characterize the natural product potential of GSL microbes. Here, we investigate the bacterial diversity of two important regions within GSL, describe the first genomic characterization of Actinomycetota isolated from GSL sediment, including the identification of two new Actinomycetota species, and provide the first survey of the natural product potential of GSL bacteria.

Current and future perspectives of a microalgae based circular bioeconomy to manage industrial wastewater– A Systematic Review

AbstractPost technological advancements and industrialisation, the recovery of resources by treating wastewater is gaining momentum. As the global population continues to grow, the need for water is becoming increasingly urgent. Therefore, the re‐utilisation of water is becoming an increasingly important factor in the preservation of life on this planet. Wastewater is classified according to its source of origin. When left untreated, the effluent causes several environmental hazards and poses health issues as they have higher concentrations of nutrients and toxic heavy metals. Currently, several conventional methods exist to treat and handle wastewater, but they generate secondary waste post‐treatment and are not sustainable. Microalgae‐based treatment of wastewater is highly sustainable, cost‐efficient and aligns with the concept of circular bioeconomy. The biological treatment of effluents using microalgae has several advantages. Approximately 1.83 kg of CO2 is sequestered per kg of the dry biomass during microalgae cultivation. Among all the sustainable alternatives, microalgae offer better biomass productivity by utilising a higher concentration of nutrients in wastewater. The wastewater‐grown microalgae have higher efficiency in producing commercially important secondary metabolites. This systematic review highlights the competence of microalgae in different wastewater sources and their industrial perspectives. This also gives an overview of the biproducts produced from microalgae‐based wastewater treatment.

Assessment of Toxic Heavy Metal Content in Children Toys

The children toys are the most favorable things for children to play. But these children toys are not safe from toxic chemicals too. There is presence of different toxic heavy metals such as mercury, lead, barium, chromium, zinc etc. The standard value for different heavy metals is set up by the government of Nepal that came into effective from July 15, 2017. The standard was set up for the 12 toxic heavy metals as cadmium, chromium, lead, mercury, zinc, antimony, arsenic, barium, bisphenol A, bromine, selenium and phthalates. The study was focused on the study of the compliance of toxic heavy metals in children toys with the national standard. For the study total 52 toys were collected from different places of Nepal: Bhaktapur, Kathmandu, Lalitpur, Chitwan, Janakpur and Nepalgunj from the local vendors to the supermarkets. The toys were generally made up of plastic, rubber, metal, foam etc. After the collection and sampling of the toys they were tested in the lab of Nepal Handicraft Association of Nepal Bureau of Standard and Metrology (NBSM) by the X-Ray Fluorescence (XRF) technology. Among the 52 toys, no any heavy metals were detected in 15 toys and 37 toys were detected with multiple toxic heavy metals. The heavy metals detected in the toys were lead, cadmium, bromine, chromium, zinc and barium. Even most of the detected result is under the compliance it is very serious issue that the non-compliance result of heavy metals like lead is very much more (4688 ppm) than the standard value (90 ppm) in the toy: tortoise. In the same way, 22 children toys have the labelling and rest do not have the labelling. But the labelled children toys don’t have the labelling about the chemical safety. Though the national standard has been formulated the local or the parents themselves are unaware about the toxic heavy metals present in the toys. As well there has raised a big confusion in the standard of the toxic heavy metals as the new standard has been published omitting the standard of the heavy metals as phthalates, BPA, bromine and zinc. Thus, these points should be considered in order to implement the standard effectively and to save the children from the chemical hazards.

Chlorella pyrenoidosa as a potential bioremediator: Its tolerance and molecular responses to cadmium and lead

Heavy metal contamination negatively affects plants and animals in water as well as soils. Some microalgae can remove heavy metal contaminants from wastewater. The aim of this study was to screen green microalgae (GM) to identify those that tolerate high concentrations of toxic heavy metals in water as possible candidates for phytoremediation. Analyses of the tolerance, physiological parameters, ultrastructure, and transcriptomes of GM under Cd/Pb treatments were conducted. Compared with the other GM, Chlorella pyrenoidosa showed stronger tolerance to high concentrations of Cd/Pb. The reduced glutathione content and peroxidase activity were higher in C. pyrenoidosa than those in the other GM. Ultrastructural observations showed that, compared with other GM, C. pyrenoidosa had less damage to the cell surface and interior under Cd/Pb toxicity. Transcriptome analyses indicated that the “peroxisome” and “sulfur metabolism” pathways were enriched with differentially expressed genes under Cd/Pb treatments, and that CpSAT, CpSBP, CpKAT2, Cp2HPCL, CpACOX, CpACOX2, and CpACOX4, all of which encode antioxidant enzymes, were up-regulated under Cd/Pb treatments. These results show that C. pyrenoidosa has potential applications in the remediation of polluted water, and indicate that antioxidant enzymes contribute to Cd/Pb detoxification. These findings will be useful for producing algal strains for the purpose of bioremediation in water contamination.

Phytoremediation Indices of Water Hyacinth (Eichhornia crassipes) Growing in Panteka Stream, Kaduna, Nigeria

The aquatic environment is incessantly polluted by the release of high toxic concentrations of heavy metals which are bio-accumulative and persistent in nature. This investigation was conducted to assess the phytoremediation potential of water hyacinth (Eichhornia crassipes) growing in Panteka stream, Kaduna where mechanic and farming activities are carried out. Having three sampling points (A, B and C) and pond water, where farming is predominant served as the control site (D) using phytoremediation indices. The root and shoot samples of E. crassipes grown at the sampling points (A, B, C) and the control were analyzed to determine heavy metal concentrations of cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) through Atomic Absorption Spectrophotometry (AAS). The phytoremediation indices were calculated via bioaccumulation coefficient and translocation factor. The results showed that the root samples had higher accumulation of heavy metals than the shoot samples. During the analysis the heavy metal Zn was noted to be accumulated the highest in roots and shoots (335.32 ± 23.6 and 256.52 ± 30.82) mg/kg at sampling point B respectively. In this present analysis heavy metals were translocated efficiently and had bioaccumulation coefficient and translocation factor greater than one. Nickel had the highest bioaccumulation coefficient and translocation factor, and Zn had a translocation factor that was less than one across all samples. This implies that E. crassipes is a potential hyperaccumulator plant for phytoremediation.

Effects of foliar selenium application on Se accumulation, elements uptake, nutrition quality, sensory quality and antioxidant response in summer-autumn tea

Summer-autumn tea is characterized by high polyphenol content and low amino acid content, resulting in bitter and astringent teast. However, these qualities often lead to low economic benefits, ultimately resulting in a wastage of tea resources. The study focused on evaluating the effects of foliar spraying of glucosamine selenium (GLN-Se) on summer-autumn tea. This foliar fertilizer was applied to tea leaves to assess its impact on plant development, nutritional quality, elemental uptake, organoleptic quality, and antioxidant responses. The results revealed that GlcN-Se enhanced photosynthesis and yield by improving the antioxidant system. Additionally, the concentration of GlcN-Se positively correlated with the total and organic selenium contents in tea. The foliar application of GlcN-Se reduced toxic heavy metal content and increased the levels of macronutrients and micronutrients, which facilitated adaptation to environmental changes and abiotic stresses. Furthermore, GlcN-Se significantly improved both non-volatile and volatile components of tea leaves, resulting in a sweet aftertaste and nectar aroma in the tea soup. To conclude, the accurate and rational application of exogenous GlcN-Se can effectively enhance the selenium content and biochemical status of tea. This improvement leads to enhanced nutritional quality and sensory characteristics, making it highly significant for the tea industry.

Combination of intercropping maize and soybean with root exudate additions reduces metal mobility in soil-plant system under wastewater irrigation

The effects of root exudates and irrigation with treated wastewater on heavy metal mobility and soil bacterial composition under intercropping remain poorly understood. We conducted a pot experiment with maize and soybean grown in monocultures or intercultures, irrigated with either groundwater or treated wastewater. In addition, the pre-collected root exudates from hydroponic culture with mono- or inter-cropped maize and soybean were applied to the soil at four levels (0 %, 16 %, 32 % and 64 %). The results showed that application of root exudates increased plant growth and soil nutrient content. The analysis of “Technique for Order of Preference by Similarity to Ideal Solution” for higher plant biomass and lower soil Cd and Pb concentrations indicated that the best performance of soybean under treated wastewater irrigation was recorded under intercropping applied with 64 % of exudates, with a performance score of 0.926 and 0.953 for Cd and Pb, respectively. The second-best performance of maize under treated wastewater irrigation was also observed under intercropping applied with 64 % of exudates. Root exudate application reduced heavy metals migration in the soil-plant system, with a greater impact in intercropping than in monocropping. In addition, certain soil microorganisms were also increased with root exudate application, regardless of irrigation water. This study suggests that appropriate application of root exudates could potentially improve plant growth and soil health, and reduce toxic heavy metal concentrations in soils and plants irrigated with treated wastewater.

Evaluation of the Carbohydrate Composition of Crabapple Fruit Tissues Native to Northern Asia.

A comprehensive comparative analysis of the carbohydrate composition (soluble sugars and pectins) of fruit tissues of Malus baccata, Malus mandshurica, Malus chamardabanica, and Malus sachalinensis, characteristic of the vast territory of Eastern Siberia and the Far East, was carried out. It was shown that a large part of the soluble carbohydrates of the studied species were represented by transport sugars-sorbitol and sucrose. These compounds also provided the main variability in the carbohydrate composition of fruits in the studied material. The polymers pectins and protopectins isolated from the studied fruits were highly methoxylated (up to 60-70%), and their content averaged about 6% of dry weight. The greatest length of pectin polymers was found in the fruit tissues of M. chamardabanica and M. sachalinensis. Data on elemental analysis of fractions of pectins and protopectins of all studied species showed the absence of potentially toxic concentrations of heavy metals. Of note is the rather high content of calcium in both polymer fractions of the four studied species, while its content in protopectin is significantly higher. In addition, in all cases, the presence of low-molecular-weight oligosaccharide molecules with a low-dispersed linear structure was revealed in the tissues of the fruits. It is worth noting that the high content of ascorbic acid was observed in the fruits of all studied species. In addition to being of fundamental interest, information about the carbohydrate composition of the wild Malus species can be useful for apple breeding when choosing sources of genes underlying useful traits.