High Selenium Concentrations Research Articles

Proteomics Provide Insight into the Interaction between Selenite and the Microalgae Dunaliella salina

Dunaliella salina is currently one of the most commercially valuable microalgae species in the world. In reponse to selenite, D. salina is a microalgae with a high selenium content, thereby increasing its value, which is crucial for increasing its economic value as a nutrional supplement. However, the effects of selenite on D. salina are still unclear, and its molecular mechanism of the response to selenite stress is also elusive. Here, in order to study the effects of selenite on D. salina and the corresponding regulatory mechanism, we characterized the physiological phenotypes of D. salina under different selenite concentrations and carried out a quantitative proteomic study. The results showed that the effective concentration for 50% growth inhibition (EC50) of the algae was 192.7 mg/L after 11 days of cultivation. When selenite concentration was lower than 100 mg/L, selenite did not hinder the growth of D. salina in the early stage, but shortened the cell growth cycle, although cell growth was significantly inhibited when the concentration of selenium was higher than 250 mg/L. Bioaccumulation experiments showed that the content of intracellular selenium in D. salina cells reached the highest level under the treatment with 50 mg/L selenite, and the contents of total selenium and organic selenium in D. salina cells were 499.77 μg/g and 303.01 μg/g (dry weight), respectively. Proteomic analysis revealed that a series of proteins related to stress responses, amino acid metabolism and energy production pathways were profoundly altered by the selenite treatment. Glutathione peroxidase (GPX7), a selenium-containing protein, was identified in the group given the selenium treatment. Moreover, proteins involved in photoreactions and oxidative phosphorylation were significantly upregulated, indicating that D. salina effectively balanced the energy demand and energy production under selenite stress. This study provides novel insights into the responses to selenite of D. salina, a microalgae candidate as a biological carrier of selenium and would be helpful for the development of industrial strains rich in selenium.

Metabolism of microelements in cattle of the holsteen breed in biogeochemical conditions of the Astrakhan region

In connection with the intensification and specialization of agricultural production, in particular animal husbandry, in the Astrakhan region, the volume of work of veterinary specialists has sharply increased in carrying out planned measures to prevent and improve methods of treating internal noncommunicable diseases, as well as the study of metabolic disorders in productive animals, in particular, by application of biotic doses of microelements in animal husbandry. Our work presents data from biogeochemical studies of pasture ecosystems in the Astrakhan region.The studies were carried out in the spring -summer period of 2021-2022 on groups of different ages (6 months, 12 months, 36 months, 72 months) of Holstein cattle owned by citizens and farms of Limansky, Kamyzyaksky and Privolzhsky districts of the Astrakhan region.In addition, in 10 cattle animals, during planned slaughter, various tissues and organs were taken for analysis in order to determine the level of trace elements.Determination of the levels of trace elements in the ecosystem was carried out in the Astrakhan region at the latitude 46° 20’58" (46° 20'98) north latitude and longi tude 48°2'26" (48° 2'44) east longitude.Trace elements in the selected samples of the pasture ecosystem, as well as in the organs and tissues of cattle, were determined by the atomic absorption method. A low level of trace elements was found in the soil, plants and feed of the ecosystem of the Astrakhan region relative to the "reference" chernozem region, where animal hypomicroelementoses and regulatory data are not recorded.The highest concentration of iodine was recorded in the blood - 0.58 ± 0.008 mg/kg, and the lowest - in the muscle tissue (0.09 ± 0.002 mg/kg), the highest concentration of selenium was determined in the tissues of the kidneys and liver (0.74 ± 0.018 and 0 .72 ± 0.113 mg/kg, respectively), and the smallest - in the muscles and lungs. The concentration of manganese in the body of cattle ranged from 32.98 ± 1.18 to 67.46 ± 1.33 mg/kg.

Processing Gray Selenium in Phosphonium-Based Ionic Liquids.

The dissolution of gray selenium in tetraalkylphosphonium acetate ionic liquids was investigated by UV-vis, NMR, and Raman spectroscopy as well as quantum chemical calculations and electrochemical methods. Acetate anions and tetraalkylphosphonium cations facilitate the formation and stabilization of oligoselenides Sen2- and cationic Se species in the ionic liquid phase. Chemical exchange of selenium atoms was demonstrated by variable-temperature 77Se NMR experiments. Additionally, uncharged cycloselenium molecules exist at high selenium concentrations. Upon dilution with ethanol, amorphous red selenium precipitates from the solution. Moreover, crystalline Se1-xTex solid solutions precipitate when elemental tellurium is added to the mixture as confirmed by powder X-ray diffraction and Raman spectroscopy.

Preparation and anti-tumor activity of selenium nanoparticles based on a polysaccharide from Paeonia lactiflora

The combination of selenium and polysaccharides is one of the significant ways to ameliorate the anti-cancer effects of polysaccharides. PLP50-1, a homogeneous polysaccharide purified from the aqueous extract of Paeonia lactiflora, had a molecular weight of 1.52 × 104 Da and consisted of α-D-Glcp-(1→, →4)-α-D-Glcp-(1→, →6)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, and →6)-β-D-Fruf-(2→. PLP50-1 showed weak anti-tumor effects against A549 cells. To ameliorate the activity of PLP50-1, the complex nanoparticles combining P. lactiflora polysaccharide with selenium were constructed successfully. Structural properties of the polysaccharide-based selenium nanoparticles (PLP-SeNPs) were clarified using various means. The results displayed that a kind of monodisperse spherical nanoparticles containing high selenium content (39.1 %) with controllable size was constructed and showed satisfactory stability. The cellular anti-tumor assay indicated that PLP-SeNPs had stronger antiproliferative activity against A549 cells than PLP50-1. Additionally, the zebrafish experiments displayed that PLP-SeNPs inhibited the proliferation and migration of A549 cells significantly and blocked the angiogenesis.

Whole blood trace element and toxic metal concentration in dogs with idiopathic epilepsy and healthy dogs: A case-control study.

Idiopathic epilepsy (IE) is the most common neurological disease in dogs. Multiple genes and environmental factors interact to cause clinical signs, although the pathogenesis remains poorly understood. Extensive evidence from recent decades shows that trace elements play a role in epilepsy in humans, and recently it was shown for the first time that also dogs with IE have altered trace element status. On the other hand, toxic metals may cause seizures but research on their role in canine IE is lacking. Therefore, we aimed to investigate trace element and toxic metal concentrations in whole blood from dogs that had been diagnosed with IE and compare them to those of healthy dogs. Whole blood concentrations of trace elements (selenium, zinc, copper, manganese, iron, and chromium) and toxic metals (arsenic, cadmium, mercury, and lead) were analyzed from 19 dogs that had been diagnosed with IE by board-certified neurologists and 19 healthy control dogs using inductively coupled plasma mass spectrometry. The concentrations in study and control group were compared using the Mann-Whitney U test. Dogs diagnosed with IE had significantly higher blood copper concentration (P = 0.007), higher copper/zinc ratio (P = 0.04), and higher selenium concentration (P < 0.001), as well as lower chromium concentration (P = 0.01) when compared to healthy dogs. Treatment of IE with potassium bromide was associated with a significant elevation in blood arsenic concentration (P = 0.01). In conclusion, the present results support the role of altered trace element status in dogs diagnosed with IE and suggest that copper, selenium, and chromium may be involved in the pathogenesis of canine epilepsy or seizures. The results also suggest that potassium bromide may alter arsenic metabolism in dogs.

Determination of the Micronutrient (Vitamin A, C, E, Zinc and Selenuim) Content of Four Indigenous Aromatic Spices in Nigeria

Micronutrients are nutrients required for human’s physiological functions and health maintenance. They are described as organic compounds required in micrograms or milligrams This study is aimed at comparing the micronutrient (VitaminA, C, E, zinc and selenuim) content of four indigenous spices (Scent leaf, garlic, Aidan seed and guinea pepper) in Nigeria. Standard analytical methods was utilized for the analysis. Results revealed that Xylopiaaethiopca (guinea pepper) had the highest amount of vitamin C and E contents (38.17mg/100g and 113.63mg/100g)respectively. Tetrapleuratetratera contained the highest concentration of Zinc and selenium (4.74mg/g and 3.39mg/g) content while Allium Sativum (garlic) has the highest amount of beta-carotene (1.75mg/g).Overall, these results demonstrate that these different spices possess varying levels of essential vitamins and minerals. Guinea pepper and garlic are particularly rich in vitamin C, vitamin E, and beta-carotene, while Tetrapleuratetratera stands out for its high zinc and selenium content. Incorporating these spices into the diet can provide additional nutritional and potential health benefits.

Proximate composition and characterization of the vitamins and minerals of dandelion (Taraxacum officinale) from the Middle Doce River region – Minas Gerais, Brazil

This study aimed to determine the chemical composition and the vitamin, carotenoid, and mineral profile in dandelion (Taraxacum officinale) collected from the Middle Doce River region (Médio Rio Doce) in the state of Minas Gerais, Brazil. To accomplish this, the physicochemical parameters, such as titratable acidity, pH, and soluble solids were determined, in addition to the evaluation of the plants’ proximate composition (moisture, ash, proteins, dietary fibers, and lipids). The vitamin E, carotenoids and vitamin C were determined by HPLC and the minerals were analysed by inductively coupled plasma atomic emission spectrometry. The T. officinale samples presented a low content of macronutrients, a total energy value of 27.88 kcal.100 g−1 FW, a high fiber content (3.7 g.100 g−1 FW), low levels of total vitamin E (43.67 μg.100 g−1 FW), total carotenoids of 11.95 g.100 g−1 FW, and did not present vitamin C in detectable levels. The mineral analysis revealed a high concentration of iron, manganese, copper, zinc, and selenium, and small amounts or traces of aluminium, cadmium, nickel, and chromium. In conclusion, T. officinale was shown to be an important source of nutrients, especially fiber, iron and manganese.

Improving the productive traits of steers when using selenium-containing feed additives in their rations

Currently, there is great interest in the use of selenium preparations in animal husbandry. Chickpeas are high in selenium and protein. The feed additive benut made on the basis of chickpeas has a high content of selenium. At the same time, an active interaction of selenium with proteins was revealed. In this regard, the study of the beef productivity of steers when using the drug DAFS-25 in the ration separately and together with the feed additive benut is important and relevant. The purpose of the work was to increase the meat productivity and quality of beef of steers when using the selenium-containing drug DAFS-25 in rations separately and in combination with the high-protein feed additive benut. In the experiment, the steers of the 1st control group received the main ration (MR); the 2nd experimental – MR + DAFS-25 (1,6 mg/kg of concentrates); the 3rd experimental – MR + 0,5 kg of benut feed additive (0,5 kg/head/day) instead of an equivalent amount of concentrates + DAFS-25 to ensure the content of selenium, as in the ration of animals of the 2nd experimental group. The beef productivity of fattened steers of Aberdeen Angus breed, indicators of blood composition, digestibility and assimilation of feed nutrients, beef quality and effi ciency of its production were studied. The economic evaluation of the research results showed that on average 1 head additional costs from the use of selenium-containing additives amounted to 140,6 rubles in the 2nd experimental group and 138,7 rubles in the 3rd experimental group. The use of these additives made it possible to reduce the prime-cost of 1 c of growth in the 2nd experimental group by 24,9 and the 3rd group by 265,8 rubles. Profi ts from the sale of beef in the 2nd experimental group were received by 84,4 rubles more and in the 3rd group by 574,8 rubles more than in the 1st control group. In the 2nd and 3rd experimental groups the level of profitability increased by 1,2 and 13,2 abs.% compared with the 1st experimental group, where it amounted to 27,3 %.

Depthwise Variation of Selenium in Groundwater in Parts of Punjab, India

ABSTRACT Selenium is an essential trace element in human diet with carcinogenic effect when consumed in excess. This paper examines the depthwise variartion of selenium in the aquifers of northeastern Punjab (India) in the Indo-Gangetic Plains in a piedmont zone. Out of 210 km2 hydrogeologically studied area in parts of Hoshiarpur and Nawanshahr districts of Punjab State, about 50% of area was found affected by high selenium concentration problem in groundwater. Three aquifer groups were identified, i.e., aquifer group I, II and III with depth ranges of about 75-95 m (thickness ~90 m), 120-230 m (thickness ~110 m) and beyond 255 m, respectively. A clay horizon of about 15-35 m thickness separates aquifer group of I and II and that of about 15-30 m thickness aquifer group of II and III. Aquifer group I is unconfined, aquifer group II is semi-confined and aquifer group III is confined in nature. High concentrations of selenium is observed in aquifer groups I and II with concentrations decreasing with depth. Aquifer group III is devoid of selenium. The symptoms of high contents of selenium started emerging when people deepened their wells in the 1970s to a depth of 20-45 m in a sandy clay horizon. This, however, is yet to be verified and warrants further investigation.

Dual RNA and 16S ribosomal DNA sequencing reveal arbuscular mycorrhizal fungi-mediated mitigation of selenate stress in Zea mays L. and reshaping of soil microbiota

Excessively high concentrations of selenium (Se) in soil are toxic to crop plants, and inoculation with arbuscular mycorrhizal fungi (AMF) can reverse Se stress in maize (Zea mays L.). To investigate the underlying mechanisms, maize seedlings were treated with sodium selenate (5 mg Se[VI] kg-1) and/or AMF (Funneliformis mosseae and Claroideoglomus etunicatum). Dual RNA sequencing in mycorrhiza and 16 S ribosomal DNA sequencing in soil were performed. The results showed that Se(VI) application alone decreased plant dry weight, but increased plant Se concentration, total Se content (mainly selenocysteine), and root superoxide content. Inoculation with either F. mosseae or C. etunicatum increased plant dry weight, decreased Se accumulation and selenocysteine proportion, enhanced root peroxidase activity, and alleviated oxidative stress in Se(VI)-treated plants. Inoculation also downregulated the expression of genes encoding Se transporters, assimilation enzymes, and cysteine-rich receptor-like kinases in Se(VI)-stressed plants, similar to plant–pathogen interaction and glutathione metabolism related genes. Conversely, genes encoding selenium-binding proteins and those related to phenylpropanoid biosynthesis were upregulated in inoculated plants under Se(VI) stress. Compared with Se(VI)-free plants, Se tolerance index, symbiotic feedback percentage on plant dry weight, and root colonization rate were all increased in inoculated plants under Se(VI) stress, corresponding to upregulated expression of ‘key genes’ in symbiosis. AMF inoculation increased bacterial diversity, decreased the relative abundances of selenobacteria related to plant Se absorption (e.g., Proteobacteria and Firmicutes), and improved bacterial network complexity in Se(VI)-stressed soils. We suggest that stress-mediated enhancement of mycorrhizal symbiosis contributed to plant Se(VI) tolerance, whereas AMF-mediated reshaping of soil bacterial community structure prevented excessive Se accumulation in maize.

Age-related alterations in the nutritional quality of Arctic grayling (Thymallus arcticus).

The biochemical composition of the muscle in Arctic graylings at three age stages was evaluated and compared. For conventional biochemical composition, there was no significant difference in the crude protein content among the three age stages, but the crude fat content in the 1 year old was significantly lower than that of the others (P<0.05). For amino acids composition, there was no significant difference in the content of essential amino acids and delicious amino acids among the three age stages, but the essential amino acid index of the 2 year old was the highest (72.205), indicating that its essential amino acid composition was more suitable for human needs. For fatty acids composition, the content of monounsaturated fatty acids (2.759mg/g) and polyunsaturated fatty acids (3.422mg/g) of the 3 year old was significantly higher than that of the others (P<0.05), and it also had relatively lowest atherogenicity index (0.419) and thrombogenicity index (0.179) and the highest hypocholesterolemic/hypercholesterolemic fatty acid ratio (2.404), indicating that its fatty acid composition was healthier and more beneficial to the prevention of human cardiovascular and cerebrovascular diseases. For minerals composition, the contents of iron, zinc, and copper increased with age, while the contents of selenium and manganese decreased with age, with the highest selenium content in the 1 year old (1.522mg/kg). The chromium, arsenic, lead, and cadmium contents were all lower than the Chinese national standard. In conclusion, the nutritional composition of Arctic graylings variated with age and consumers could select suitable Arctic graylings based on their nutritional needs. PRACTICAL APPLICATION: This work analyzed the nutritional components in the muscle of Arctic graylings at different ages, which can provide an effective reference for consumers when purchasing Arctic graylings.

Microbial functional communities and the antibiotic resistome profile in a high-selenium ecosystem

Enshi City, in the Hubei Province of China, is known as the world capital of selenium with the most abundant selenium resource. An important selenium hyperaccumulator plant, Cardamine violifolia, was found to naturally grow in this high-selenium ecosystem. However, relatively little is known about the impact of the selenium levels on microbial community and functional shifts in C. violifolia rhizosphere. Here, we tested the hypothesis that underground microbial diversity and function vary along a selenium gradient, including antibiotic resistance genes (ARGs). Comprehensive metagenomic analyses, such as taxonomic investigation, functional detection, and ARG annotation, showed that selenium, mercury, cadmium, lead, arsenic, and available phosphorus and potassium were correlated with microbial diversity and function. Thaumarchaeota was exclusively dominant in the highest selenium concentration of mine outcrop, and Rhodanobacter and Nitrospira were predominant in the high-selenium ecosystem. The plant C. violifolia enriched a high concentration of selenium in the rhizosphere compared to those in the bulk soil, and it recruited Variovorax and Polaromonas in its rhizosphere. Microbial abundance showed a trend of increasing first and then decreasing from low to high selenium concentrations. Annotation of ARGs showed that the multidrug resistance genes adeF, mtrA, and poxtA, the aminoglycoside resistance gene rpsL, and the sulfonamide resistant gene sul2 were enriched in the high-selenium system. It was discovered that putative antibiotic resistant bacteria displayed obvious differences in the farmland and the soils with various selenium concentrations, indicating that a high-selenium ecosystem harbors the specific microbes with a higher capacity to enrich or resist selenium, toxic metals, or antibiotics. Taken together, these results reveal the effects of selenium concentration and the selenium hyperaccumulator plant C. violifolia on shaping the microbial functional community and ARGs. Metalloid selenium-inducible antibiotic resistance is worth paying attention to in future.

Methylselenized glucose: An efficient organoselenium fertilizer enhancing the selenium content in wheat grains

Selenium (Se) is an essential mineral element for human and other animals, and has been proved to improve plant growth and development and tolerance to different abiotic stresses. Selenium biofortification is considered to be a key strategy to increase the selenium content of edible parts of crops, which is helpful for improving human health. In this work, foliar fertilization with different concentrations and selenium forms was carried out on two wheat varieties at the flowering stage to compare the selenium enrichment effect of Na2SeO3, methylselenized selenocysteine (MSC), methylselenized glucose (MSG) and methylselenized lactide (MSL) in wheat grains. Surprisingly, MSG was found to be the preferable fertilizer. After the application of MSG, the highest selenium content in wheat gains reached 6 mg/kg in this experiment, and the average selenium content was 2–4 times versus that of Na2SeO3 application. Since MSG has high utilization rate and is easily available at relatively low cost, it can be employed as a potential selenium source for selenium biofortification to enhance the added value of agricultural industry.

Insight into the antioxidant activities of ten Fabaceae plant species that are medicinally used by the Aucan Tribal Peoples from the Republic of Suriname (South America).

Fabaceae are associated with a high antioxidant activity (AA) and a high total phenolic (TPC), total flavonoid (TFC), and selenium content (SeC). In this study, the aqueous extracts from ten Fabaceae species that are medicinally used by the Aucan Tribal Peoples from Suriname (South America), were evaluated for AA using a DPPH and a FRAP assay, and for TPC, TFC, and SeC using Folin-Ciocalteu's, an AlCl3 colorimetric, and an azure B-based method. Associations between pairs of these variables were determined by Pearson correlation coefficient. One-way ANOVA with post-hoc Tukey's test was used to evaluate the data for statistically significant differences (p < 0.05). The I. stipularis (bark), C. guyanensis (bark), A. jupunba (twigs), and M. urens (fruit) extracts had the highest DPPH IC50 values (36 - 70 μg/mL) and FRAP values (346 - 573 μM FeE/100 μg) and the highest TPC (25 - 41 GAEq/100 μg), TFC (21 - 39 REq/100 μg), and SeC (4 -17 μg/g). The values for the T. indica (leaf), P. macroloba (bark), M. pigra (whole plant), S. quinquangulata (leaf), A. sensitiva (whole plant), and L. leucocephala (leaf) extracts were > 10-fold lower. AA, TPC, TFC, and SeC correlated well with each other (correlation coefficient ≥ 0.83, p ≤ 0.0030). Thus, AA, TPC, TFC, and SeC may represent important determinants of the health benefits of the former four samples but not of the others. Future studies should focus on the precise contribution of AA, TPC, TFC, and SeC to the therapeutic value of medicinal Fabaceae.

Serum Selenium Levels in Patients With Graves Disease With or Without Thyroid Ophthalmopathy

BackgroundGraves disease is one of the most common autoimmune thyroid diseases. Thyroid has the highest concentration of selenium (Se) in the body. Se plays a crucial role in the functioning of some thyroid enzymes; however, there are controversial results regarding the administration of serum Se levels in patients with Graves disease. MethodsIn this study, patients with Graves disease with orbitopathy (GO group) or without orbitopathy (GD group) were recruited. Healthy individuals without a history of any disease were enrolled as the control group. Serum Se and thyroid hormone levels, including T3, T4, and thyroid-stimulating hormone (TSH), were measured using atomic absorption and radioimmunoassay techniques, respectively. ResultsIn this cross-sectional study, 60 and 56 patients and 58 healthy subjects were included in the GO, GD, and control groups. Serum Se levels in the GO, GD, and control groups were 94.53 ± 25.36 μg/dL, 96.82 ± 30.3 μg/dL, and 102.55 ± 16.53 μg/dL, respectively (P = .193). There was a reverse association between the serum Se level and thyroid hormones, including T3, T4, and TSH, in the GO group. However, serum Se levels exhibited a significant reverse association with T4 and TSH hormones but not with T3 in the GD group. ConclusionOur results showed no significant differences in the serum Se levels in the GO and GD groups compared with that in the control group. In addition, we did not detect any significant difference in the serum Se levels between the GO and GD groups.

The nutritional therapeutic values and chemical properties of goat milk

Goat is known as poor man’s animal. The fat globules are smaller in goat milk, which makes it easily digestible. Polyunsaturated fatty acids in goat milk fat, is mainly responsible for anticancerous behavior of goat milk. Although protein is somewhat low in goat milk than cow milk, the digestibility of goat milk protein is higher compared to cow milk protein. Taurine present in goat milk is reported to have inhibitory action on cardiovascular disease leads to synthesis of essential amino acids. Goat’s milk contains less lactose than cow’s milk, which is beneficial to lactose intolerance patients. Higher selenium concentration in goat milk, results in platelet regeneration when suffering from dengue fever. Bioactive peptides released during fermentation and invitro digestion are reported to produce antioxidant and antimicrobial peptides. Sialic acid present in caprine milk is also reported to help fast brain development. As compared to milk of other milch animals, goat’s milk has great potential to prevent various diseases. Beside nutritional properties, goat milk possesses potent nutraceutical and Therapeutic properties making it most suitable for infants, older and convalescent people. In this review, strong nutraceutical power of caprine milk is briefly explored.

Inverse Association between Serum Selenium Level and Severity of Liver Fibrosis: A Cross-Sectional Study.

Selenium has been well recognized for its important role in human health. Prior studies showed that low serum selenium was associated with various diseases, including cardiovascular disease, cancer, infertility, and cognitive decline. Recent studies demonstrated an association between selenium deficiency and liver cirrhosis. In our study, we aimed to explore the association between serum selenium levels and severity of liver fibrosis. In total, 5641 participants at an age of 12 and above, from the 2017–2018 United States National Health and Nutrition Examination Survey, were enrolled. The severity of liver fibrosis was determined by liver ultrasound transient elastography. There was a significant linear decrease in liver stiffness measurement (LSM) values in male groups with increased serum selenium levels. The beta coefficient (β) = −1.045 in male groups. A significantly negative association was also observed in the group of age ≥ 60. In addition, those in the highest quartile of serum selenium had lower LSM values (β = −0.416). This is the first study using LSM to demonstrate the correlation between selenium deficiency and severity of liver cirrhosis. Our findings suggest that a high plasma selenium concentration is negatively correlated with the severity of liver cirrhosis and there are gender and age differences.

Nerium oleander L. as a Phytoremediation of Heavy Metals in Diyala Governorate – Iraq

The study samples were collected during the months of April and May 2022, samples were collected from different regions in Diyala Governorate – Iraq. The study aimed to assess the role of oleander plant in the phytoremediation of heavy metals (lead , cadmium , arsenic and selenium) within Diyala Governorate by estimating their concentration in the leaves of the plant and the soil on which it grows as well as calculating the bioaccumulation factor (BAF). Al-Muqdadiyah Industrial area was one of the most polluted areas with lead, the highest concentration of lead appeared in the leaves of the oleander plant grown in this area, as well as the soil on which it grows (2.452 and 0.904 ) ppm respectively. The highest concentration of cadmium was recorded for oleander leaves in the old city of Baqubah (2.208ppm), while the highest concentration appeared in the soil on which it grows in the Al-Muqdadiyah Industrial area (0.363ppm). The Al-Muqdadiya industrial area also recorded the highest concentration of arsenic in the leaves of the oleander plant ( 0.559 ppm) ,but the highest concentration in the soil on which it grows was in the central city of Al-Muqdadiyah (0.218ppm) , followed by the industrial city off Al-Muqdadiyah.( 0.132ppm) . The highest concentration of selenium appeared in the industrial city of Al-Muqdadiya in both the leaves of the oleander plant and the soil on which it grows (0.441 and 0.104) ppm. The value of the bioaccumulation factor (BAF) shows the efficiency of the oleander plant in the phytoremediation of cadmium, followed by lead, arsenic and selenium in varying proportions. Keywords : Phytoremediation , Neium oleander , Heavy metals DOI: 10.7176/JEES/12-9-04 Publication date: September 30 th 2022

Selenium recovery from wastewater by the green microalgae Chlorella vulgaris and Scenedesmus sp.

Selenium (Se) is an important element for many living organisms and its supplementation may be needed in food, feed, and soil to make up for its deficiency. At the same time, high selenium concentrations can harm the environment, thus its management in sewage and the study of its removal from waste streams are important. Microalgae-based systems may be used for wastewater treatment and nutrients recovery, while producing biomass for bioproducts or bioenergy. In this study, Chlorella vulgaris and Scenedesmus sp. grown in urban wastewater with different selenium concentrations (50–1000 μg Se/L) were evaluated for their resistance and selenium removal/recovery efficiency. Chlorella vulgaris and Scenedesmus sp. were able to remove up to 43 and 52 % of Se from wastewater, respectively. Chlorella vulgaris accumulated up to 323 mgSe/kg DW (in urban wastewater with 1000 μg Se/L). The Se-rich biomass produced may be applied to the supplementation of animal feed or used for biofortification of crops.

Impact of management systems on selenium and zinc levels, heterophil: Lymphocyte ratio as biomarkers of immunity in chickens

This study investigated the impact of poultry management systems (intensive and extensive) on selenium and zinc concentrations and heterophil to lymphocyte ratio in chickens. Sixty chickens comprising 20 broilers, 20 local chickens and 20 layers obtained from poultry markets and houses around Ibadan, Oyo State, Nigeria were used in this study. Five millilitres of blood were collected through the brachial vein to analyse for selenium, zinc and complete blood count using atomic absorption spectrophotometry and standard haematological methods, respectively. There was a significantly (P&lt;0.05) higher red blood cell, haemoglobin and pack cell volume values in local chickens raised in the extensive management system compared to broilers and layers raised in the intensive management system. There was no significant difference (P&gt;0.05) in the white blood cell count between layers and local chickens. However, layers had higher white blood cell counts than local chickens. In contrast, local chickens had significantly (P&lt;0.05) lower white blood cell count than broilers. The respective lymphocyte and heterophil counts were significantly (P&lt;0.05) higher and lower in local chickens raised extensively compared to layers raised intensively. There were no significant differences (P&gt;0.05) in monocyte, eosinophil and basophil count in chickens raised from both management systems. Chickens raised in the extensive management system had a significantly (P&lt;0.05) higher selenium concentration with a lower heterophil to lymphocyte ratio than those raised in the intensive management system but had a significantly (P&lt;0.05) lower zinc concentration. Therefore, high selenium levels and low heterophil to lymphocyte ratio could contribute to the resistance of chickens to various stressors associated with an extensive management system as selenium is a known immunomodulator.