Inorganic Se Research Articles

Effects of mixed selenium sources on the physiological responses and blood profiles of lactating sows and tissue concentration of their progeny.

This study was conducted to investigate the effects of selenium benefits on the physiological responses, litter performance, blood profiles and milk composition of lactating sows and tissue concentration of their progeny when mixed form of selenium was provided in a lactation diet. A total of 45 multiparous sows (Yorkshire×Landrace) with similar body weight, backfat thickness, and parity were assigned to one of three treatments with 15 sows per treatment in a completely randomized design. Organic and inorganic selenium were mixed and added to the diet at 0.15 ppm and 0.25 ppm, respectively. A non-Se-fortified corn-soybean meal basal diet served as a negative control. Treatments were as follows: i) Control: corn-soybean meal based diet, ii) ISOS15: control+ inorganic Se 0.15 ppm+organic Se 0.15 ppm, iii) ISOS25: control+inorganic Se 0.25 ppm+organic Se 0.25 ppm. Serum selenium concentrations of sows and piglets were increased by the supplemental Se mixture at 7 days of lactation compared with the control (p<0.01, respectively). The kidney and muscle selenium concentrations of piglets were increased by the supplemental Se mixture at 21 days of lactation compared with the control (p = 0.03; p = 0.04, respectively). Consequently, supplementation with mixed inorganic and organic selenium in a lactating diet could improve the selenium status of sows and piglets; no differences were observed among the mixing levels.

Selenium-Enriched Mushroom Powder Enhances Intestinal Health and Growth Performance in the Absence of Zinc Oxide in Post-Weaned Pig Diets.

Simple SummaryThe imminent ban on zinc oxide in pig diets within the European Union is a major challenge facing the swine industry. Commercial weaning is associated with abrupt dietary, environmental and social changes resulting in stress, reduced feed intake and gut developmental issues in the post-weaned pig. Mushrooms are rich in natural bioactives and have long been regarded as a health-promoting food due to their immunomodulatory and antioxidant effects and their ability to modulate the gut microbiota. Mushrooms can become abundant in organic selenium when grown under certain conditions. The present study aimed to determine the optimum Se level, using Se-enriched mushrooms and selenite, in weaned pig diets to enhance intestinal health, performance and antioxidant capacity. Our study demonstrated that 0.3 ppm selenium inclusion, using selenium-enriched mushroom powder, led to positive effects on faecal scores and had similar pig performance compared to zinc oxide during the first 21 days post-weaning. The selenium inclusion level of 0.6 ppm, using selenium-enriched mushroom powder and selenite, enhanced pig performance and aspects of gastrointestinal health during days 21 and 39 post-weaning.This study was conducted to examine the effects of varying selenium (Se) inclusion levels, in the form of Se-enriched mushroom powder (SeMP) and selenite, on post-weaning growth performance (Period 1; day 1–21), intestinal health and antioxidant capacity (Period 2; day 21–39). Weaned pigs were blocked according to live weight, sex and litter of origin and randomly assigned to the following experimental groups: basal (basal + selenite (0.3 ppm Se)); ZnO (basal + ZnO + selenite (0.3 ppm Se)); 0.15 SeMP (basal + SeMP (0.15 ppm Se)); 0.3 SeMP (basal + SeMP (0.3 ppm Se)) and 0.6 SeMP/Sel (basal + SeMP (0.3 ppm Se) + selenite (Sel) (0.3 ppm Se)) with eight replicates/experimental group. After 21 days, the ZnO experimental group was removed from the experiment and the remaining pigs continued on their respective diet until day 39 post-weaning (Period 2). In Period 1, 0.15 SeMP supplementation reduced (p < 0.05) average daily gain (ADG), average daily feed intake (ADFI) and day 21 body weight, and increased (p < 0.05) faecal scores compared to the ZnO group. Supplementation with 0.3 SeMP and 0.6 SeMP/Sel during Period 1 resulted in similar (p > 0.05) ADG, ADFI, gain-to-feed ratio (G:F) and body weight compared to the ZnO group. However, 0.6 SeMP/Sel supplementation increased (p < 0.05) faecal scores compared to the ZnO group. In Period 2, 0.6 SeMP/Sel increased (p < 0.05) ADG, feed efficiency and day 39 body weight compared to the basal group. Supplementation with Se-enriched mushroom powder, at all inclusion levels, increased (p < 0.05) the abundance of Prevotellaceae and Prevotella, decreased (p < 0.05) the abundance of Sporobacter and increased (p < 0.05) the expression of SELENOP in the jejunum compared to the basal group. Lactobacillaceae and Lactobacillus was increased (p < 0.05) in 0.15 SeMP and 0.3 SeMP pigs compared to the basal group. Selenium deposition in muscle and liver tissue increased (p < 0.001) as a function of inclusion level while pigs supplemented with 0.3 ppm organic Se (0.3 SeMP) had an increase (p < 0.05) in total Se in the muscle compared to pigs supplemented with 0.3 ppm inorganic Se (basal). In conclusion, 0.3 SeMP supplementation led to positive effects on faecal scores and had similar pig performance compared to ZnO in Period 1, while the addition of 0.3 ppm selenite to 0.3 SeMP (0.6 SeMP/Sel) in Period 2 led to enhanced pig performance and aspects of gastrointestinal health.

Selenium-enriched peptides isolated from Cardamine violifolia are potent in suppressing proliferation and enhancing apoptosis of HepG2 cells.

Selenium (Se)-enriched peptides were isolated from Cardamine violifolia by enzymatic hydrolysis and ultrafiltration. S3 (molecular weight [MW] distribution of 3-5kDa) exhibited the strongest inhibitory effect on HepG2 cells and was thus screened using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay; it was found to have a high organic Se content. Its amino acid sequence was determined using HPLC-MS/MS. We then examined its ability to inhibit tumor cell proliferation and found that it arrested tumor cells in the S phase; moreover, it could induce cancer cell apoptosis. Following S3 treatment, we observed a decrease in mitochondrial membrane potential and an increase in cell calcium content. Upon S3 treatment at 60µg/ml, the relative activities of caspase-3 and caspase-9 increased by 1.48 times and 2.17 times, and the contents of PI3K and AKT decreased from 2.05ng/L and 1.95ng/L to 0.71ng/L and 0.50ng/L, respectively, when compared with the control group. Transcriptomic analysis revealed significant changes in the PI3K-AKT pathway following S3 treatment. This study thus established a foundation for additional development of Se-enriched peptides from C. violifolia as a functional food. PRACTICAL APPLICATION: Cardamine violifolia is a Se-tolerant cruciferous plant that can metabolically transform inorganic Se into organic Se that exists in the form of a selenoprotein. Se-enriched peptide obtained by extraction and enzymolysis of selenoprotein, as an organic combination of organic Se and peptide, possess valuable biological activities. In this paper, the effect of Se-enriched peptides of C. violifolia on tumor cells was studied via cell experiments, and its mechanism was preliminarily discussed, which should provide a theoretical basis for developing functional foods containing C. violifolia.

Selenium Speciation in Paired Whole Blood and Serum Samples From Pregnant Bangladeshi Women

ObjectivesWe aimed to characterize the relative concentrations of selected major selenium (Se) species in paired whole blood (WB) and serum samples collected from pregnant women at delivery in Dhaka, Bangladesh. Speciation analysis enabled differentiation of organic and inorganic Se, and quantification of the nutritionally bioactive reduced selenometabolite, selenoneine, which has been previously observed in WB from populations with high levels of fish consumption. MethodsPaired WB and serum specimens (n = 515) were collected at delivery among participants of the Maternal Vitamin D for Infant Growth trial. Quantification of total serum Se and total WBSe was conducted using inductively coupled plasma mass spectrometry (ICP-MS) at the Centers for Disease Control and Prevention (CDC). Speciation analyses were conducted in a subset of pairs (n = 20) to quantify selenometabolites using liquid chromatography coupled to ICP-MS at the University of Cincinnati. Concentrations of inorganic Se (IV), selenoneine, selenocysteine (SeCys), selenomethioneine (SeMet) were expressed as % of total Se. We assessed concordance between results generated across laboratories using paired t-tests. ResultsOverall (n = 515), mean (SD) serum Se and WBSe concentrations (μg/L) were 70 (14) and 135 (18), respectively, such that average Serum Se as a proportion of WBSe was 52%. Findings were similar in the speciation subset (n = 20) [total Serum Se: 82 (19); total WBSe: 138 (18), with a ratio of serum Se to WBSe: 60%]. Sums of quantified species accounted for most of the total serum Se (72 (10); 88% of total) and WBSe (135 (16); 98%). Organic forms were predominant in both serum and WB: SeCys: 15 (2) and 20 (3); and SeMet: 54 (9) and 92 (13), respectively. Selenoneine was detected in WBSe at mean concentrations of 24 (5) μg/L. Together, SeMet and selenoneine accounted for 85% of the additional WBSe not present in serum. Inorganic Se was not detected in WB but comprised 5% of serum. ConclusionsApproximately half of the Se in whole blood is in the cellular fraction. SeMet was enriched in WB and the most abundant form, relative to selenoneine which was not found in serum. Small amounts of inorganic serum Se may be artifactual due to freeze-thaw related degradation. These findings require confirmation in other settings but suggest that serum Se may not be a suitable biomarker of population status. Funding SourcesBMGF.

Impact of Sulfur on Biofortification and Speciation of Selenium in Wheat Grain Grown in Selenium-Deficient Soils

Selenium (Se) is an essential micronutrient in humans that is required for both physical and mental well-being. Low Se content in food crops is linked to Se-deficient soils globally. The aim of this study was examined the influence of sulfur (S) on the speciation and accumulation of selenium (Se) in three wheat cultivars grown in Se-deficient soils. Plants were grown in soil under glasshouse conditions with two doses of S (0 and 14 mg kg−1) as sulfate and three doses of selenium (0, 1, and 2 mg kg−1) as selenate (SeVI) in a randomized factorial design. Selenium speciation was determined using liquid chromatography inductively coupled plasma mass spectroscopy after enzymatic hydrolysis. Selenocysteine (SeCys), seleno-methyl-cysteine (SeMeCys), selenomethionine (SeMet), selenite (SeIV), and selenate (SeVI) were determined. The addition of SeVI increased the Se content in grain in all wheat cultivars compared to the control treatment. Selenium accumulated to the highest extent in leaf tissue while stem accumulated low amounts of Se. Speciation analysis in grain showed that most of the Se accumulated in wheat grain in the organic forms, SeCys and SeMeCys. Inorganic Se was below 10%, primarily as SeVI. Longsword, a multi-tillering variety, accumulated the highest proportion of SeMeCys (67%). Fertilization with S concurrently with Se resulted in decreased production of SeCys and SeMeCys in grain. The findings from this study provide new insights into the Se biofortification and speciation transformation processes in wheat as impacted by S supplementation in Se-deficient soils.

Fractionation of Dissolved Selenium Isotopic composition during a Phytoplankton Bloom in an Estuary

Selenium (Se) isotopes have been widely used to track the Earth's redox evolution based on the assumption that terrestrial Se is faithfully transported at the land-ocean interface without nonconservative behavior or biological fractionation affecting its isotope composition. However, dissolved Se isotope behavior in estuaries is poorly constrained, which calls this assumption into question. In this study, we present the first dissolved inorganic Se (DISe) isotope dataset along a salinity gradient during transport of the Changjiang river. Water and phytoplankton samples from a bloom event were collected. The δ82/76DISe values increased from 0.96‰ to 1.74‰ along the salinity gradient (from 0.1 to 34.5). The nonconservative behavior of DISe was revealed by large offsets of δ82/76DISe from theoretical mixing of the bloom waters. The dynamics of δ82/76DISe in the Changjiang Estuary (CJE) were controlled by the combination of physical mixing and biological utilization. In those bloom waters, the heavy δ82/76DISe values (1.66‰ ± 0.07‰) in the waters corresponded to the light Se isotopes for phytoplankton (−0.35‰ ± 0.18‰). The significantly increased δ82/76DISe signatures in the bloom waters due to the utilization of DISe by phytoplankton led to an Se isotope fractionation factor (reported as ε82/76Se = 1000 × (α82/76Se − 1) in) of −1.92‰ ± 0.16‰ (Rayleigh model) or −2.14‰ ± 0.18‰ (steady-state model). We propose that biological activities modify the nonconservative activity of Se and induce significant Se isotope fractionation with a factor of approximately −2‰ during transport. Our findings highlight that interpreting Se isotopes in the sedimentary record requires the consideration of nonconservative behavior and biological fractionation of Se.

Selenium accumulation and biotransformation in Streptococcus, Lactococcus, and Enterococcus strains

• Strains from LAB can accumulate and biotransform sodium selenite from growth medium. • First description of Se produced by Lactococcus lactis subsp. cremoris. • LAB transforms Se into selenocysteine and nanoparticles. • Se-enriched LAB can be used to develop new functional foods for humans. In the present study, we evaluated the ability of inorganic Se to accumulate and biotransform into different selenium species and Se nanoparticles (SeNPs) in seven bacteria from the Lactococcus , Streptococcus, and Enterococcus genera . The cytotoxicity of selenized strains to human adenocarcinoma Caco-2 and HT29 cells, the effect of selenium enrichment on antioxidant activity, and cell surface hydrophobicity of the tested strains were determined. When compared to that of lactococci and enterococci, increasing concentrations of sodium selenite in the cultivation media inhibited the growth of Streptococcus thermophilus strains. Thirty milligrams per liter Na 2 SeO 3 and its higher concentrations (50 and 100 mg/L) significantly reduced the viability of Caco-2 and HT29 cells by 40–75%. Bacteria mainly produced SeNPs and selenocysteine in Se form. Our results indicate that the tested strains can accumulate and transform inorganic selenium, which makes them promising candidates for selenization and possible application in functional foods.

Productive Performance, Serum Antioxidant Status, Tissue Selenium Deposition, and Gut Health Analysis of Broiler Chickens Supplemented with Selenium and Probiotics-A Pilot Study.

Simple SummaryFor several years, the benefits of dietary selenium or probiotics on growth and development of broilers have been reported. However, the effect of a combination of different forms of selenium and probiotics on broilers remains to be seen. Thus, the hypothesis of this study was that supplementing selenium and probiotics have positive synergistic effects and interactions on growth performance, antioxidant capacity, tissue selenium deposition, and intestinal health of broilers. The results of this study demonstrate that selenium and probiotics have positive interactions on the tissue selenium content, duodenum, and jejunum development, as well as the composition of cecum microbial, and there were no significant interactions on the growth performance, and antioxidant capacity. Overall, our findings suggest that the combination of organic selenium and probiotics is superior to inorganic or organic selenium alone in poultry production.The effect and interaction of dietary selenium (Se) and probiotics on three yellow chicken growth performance, tissue Se content, antioxidant capacity, and gut health were studied from 0 to 70 days of age. A total of 400 one-day-old broilers were distributed into four groups (I-Se, O-Se, I-Se + pros, and O-Se + pros groups) consisting of a 2 × 2 factorial design. The main factors were the source of Se (I-Se = inorganic Se: 0.2 mg/kg sodium selenite; O-Se = organic Se: 0.2 mg/kg Selenium yeast) and the level of probiotics (0.5% EM or 0% EM, the component of EM mainly includes Lactobacillus and Yeast at the dose of 2 × 108 cfu/kg and 3 × 107 cfu/kg, respectively). Each treatment had 5 duplicates consisting of 20 broilers. The results showed that the I-Se group had a greater (p < 0.05) ratio of feed: weight gain (F/G) of broilers at Starter (0–35 d) than the other treatments. Compared to the I-Se group, the O-Se group increased (p < 0.05) Se concentrations in the liver, pancreas, breast muscles, thigh muscle, and the activity of total antioxidative capacity (T-AOC) in serum, as well as the relative abundance of Barnesiella and Lactobacillus in cecum. Meanwhile, probiotics enhanced (p < 0.05) Se concentrations in the pancreas, thigh muscle, serum, and the activity of T-AOC and glutathione peroxidase (GSH-Px), the duodenum’s ratio of villi height to crypt depth (V/C), the jejunum villus height and V/C, and the ileum’s villus height. Furthermore, the significant interactions (p < 0.05) between Se sources and the level of probiotics were observed in Se concentrations in the pancreas, thigh muscle, serum, crypt depth of duodenum, and villus height of jejunum of birds, and Barnesiella abundance in the cecal. In conclusion, our results demonstrate that the combination of O-Se + pros can improve broiler early growth performance, tissue Se content in the pancreas, thigh muscle, and serum, promote intestinal development, and regulate the composition of intestinal flora, suggesting a better combination. These findings provide an effective method of nutrient combination addition to improving the performance of three yellow chickens.

Influence of Selenium Biofortification of Soybeans on Speciation and Transformation during Seed Germination and Sprouts Quality

Selenium (Se) biofortification during seed germination is important not only to meet nutritional demands but also to prevent Se-deficiency-related diseases by producing Se-enriched foods. In this study, we evaluated effects of Se biofortification of soybeans on the Se concentration, speciation, and species transformation as well as nutrients and bioactive compounds in sprouts during germination. Soybean (Glycine max L.) seedlings were cultivated in the dark in an incubator with controlled temperature and water conditions and harvested at different time points after soaking in Se solutions (0, 5, 10, 20, 40, and 60 mg/L). Five Se species and main nutrients in the sprouts were determined. The total Se content increased by 87.3 times, and a large portion of inorganic Se was transformed into organic Se during 24 h of germination, with 89.3% of the total Se was bound to soybean protein. Methylselenocysteine (MeSeCys) and selenomethionine (SeMet) were the dominant Se species, MeSeCys decreased during the germination, but SeMet had opposite trend. Se biofortification increased contents of total polyphenol and isoflavonoid compounds and amino acids (both total and essential), especially in low-concentration Se treatment. In conclusion, Se-enriched soybean sprouts have promising potential for Se supplementation and as functional foods.

Potential Mechanism and Effects of Different Selenium Sources and Different Effective Microorganism Supplementation Levels on Growth Performance, Meat Quality, and Muscle Fiber Characteristics of Three-Yellow Chickens.

A trial was conducted to investigate the effects of different Se sources, including sodium selenite (S-Se) and selenium yeast (Y-Se) and different effective microorganism (EM) addition levels on growth performance, meat quality, and muscle fiber characteristics of three-yellow chickens and its potential mechanism. A total of 400 birds were randomly distributed into 4 groups (S-Se, S-Se + EM, Y-Se, and Y-Se + EM groups) consisting of a 2 × 2 factorial arrangement. The main factors were the source of Se (ISe = inorganic Se: 0.2 mg/kg S-Se; OSe = organic Se: 0.2 mg/kg Y-Se) and the level of EM (HEMB = high EM: 0.5% EM; ZEMB = low EM: 0% EM). Each treatment had 5 replicates and each replicate consisted of 20 broiler chickens. The trial lasted for 70 days. The results showed that, in breast muscle, the broiler chickens fed OSe source decreased the pH24h, drip loss, shear force, perimeter, cross-sectional area, and diameter, but increased the and density compared with the broiler chickens fed ISe source (p < 0.05); broiler chickens supplied with HEMB level decreased the cross-sectional area and diameter, but increased the pH24h, and density compared with the broiler chickens supplied with ZEMB level (p < 0.05). In thigh muscle, OSe source and HEMB level also could improve the meat quality and change muscle fiber characteristics of broiler chickens (p < 0.05). Meat quality was correlated with the muscle fiber characteristics (p < 0.05). OSe source and HEMB level could regulate the expression levels of muscle fiber-relative genes in the breast and thigh muscles (p < 0.05). In conclusion, OSe source and HEMB level could improve the meat quality of the breast and thigh muscles of three-yellow chickens by changing the muscle fiber characteristics, and they changed the muscle fiber characteristics by regulating the expression levels of muscle fiber-relative genes.

Effects of Different Selenium Sources on the Laying Performance, Egg Quality, Antioxidant, and Immune Responses of Laying Hens under Normal and Cyclic High Temperatures.

Simple SummaryHeat stress is a major environmental stressor in livestock production, which seriously threatens the global livestock industry and causes huge economic losses. Strategies to address heat stress are mainly divided into three categories: genetic regulation, environmental regulation, and nutritional diet regulation. Among them, nutritional regulation is one of the current research hotspots. Selenium is an essential trace element for animals and humans. As a component of some anti-oxidant enzymes and selenoproteins, it plays an important role in improving anti-oxidation, anti-stress, immune function, and reproduction performance. This study investigated the effects of different selenium sources on the laying performance, egg quality, antioxidant, and immune responses of laying hens under different temperatures. The results showed that supplementation with different selenium sources can increase the egg yolk color, antioxidant capacity, and immune status, and can alleviate heat stress damage. Additionally, the effect of organic selenium is better than that of inorganic selenium.The aim of this study was to evaluate the effects of different selenium (Se) sources on the laying performance, egg quality, antioxidant, and immune responses of laying hens under different temperatures. In an 8-week experiment, a total of 480 44-week-old laying hens were randomly divided into 8 groups, with 6 replicates for each group and 10 hens per replicate, and fed with a basal diet (BK), basal diet with 0.3 mg/kg of Se from sodium selenite (SS), from Se yeast (SY), or from selenium-enriched yeast culture (SYC) under normal temperature (NT, 26 ± 2 °C) and cyclic high temperature (CHT, 26 ± 2 °C~33 ± 2 °C). CHT decreased the laying performance and serum levels of Se, immunoglobulin G (IgG), and interleukin-10 (IL-10), and significantly increased the serum free triiodothyronine (FT3), deiodinase-I (DI-I), and heat stress protein (HSPs) (p < 0.05). In addition, SYC increased the egg yolk color, and SS increased serum IgG level. SS, SY, and SYC reduced the level of interleukin-6 (IL-6) (p < 0.05). In conclusion, Se can increase egg yolk color, antioxidant capacity, and immune capacity under heat stress, and the effect of organic Se is better than that of inorganic Se.

Selenium adsorption and desorption capacity and its influence on selenium uptake by green spinach

Selenium is important to human health and must be consumed in adequate amounts through a variety of food sources, particularly vegetables. In order to identify availability of soil Se to crops, Se adsorption-desorption process in soil must be understood. In this study, an adsorption-desorption study of inorganic Se in soils of various textural classes was performed with the following concentration of Se (0–2 mg L−1) applied as Se(VI) and Se(IV). A glasshouse experiment was then conducted in a factorial (2 × 5) completely randomized design, with two Se form—Se(IV) and Se(VI)—and Se at five rates (0–60 g ha−1 Se in solution form) to green spinach. First, soil texture appeared to be the main factor controlling Se adsorption in soils. Selenite was adsorbed more, however, Se(VI) was desorbed at higher rate compared to Se(IV). Contrary to other soil types, in peat, Se(IV) was desorbed at higher level compared to Se(VI), where more than 70% was retained. Higher retention of Se(IV) was found in clayey soil. Meanwhile, from glasshouse experiment, Se uptake was higher in plants when treated with Se(VI) than with Se(IV). However, higher dry matter and antioxidant activity of green spinach was observed when Se(IV) was applied. Selenium applied as Se(IV) had greater benefits to spinach yield and antioxidant activity than Se(VI) or conventionally grown spinach (0 g ha−1), even though plants treated with Se(VI) had greater Se uptake.

Efficient entrapment of inorganic Se species in water and beer samples with functional groups-rich monolith-based adsorbent.

An efficient multiple fibers solid-phase microextraction method based on porous monolith was established for Se(IV) and Se(VI) analysis. Poly(4-vinylphenylboronic acid/styrene-co-ethylene dimethacrylate/divinylbenzene) monolith was fabricated and employed as the extraction phase for efficient entrapment of Se(IV) complexed with o-phenylenediamine, followed by elution with a methanol/formic acid (99/1.0, v/v) mixture and quantification by high-performance liquid chromatography with diode array detector. The Se(VI) species was measured by the difference between total inorganic Se and Se(IV) after pre-reduction. Different characterization techniques were employed to inspect the structure and morphology of prepared adsorbent. A series of key extraction factors were optimized so as to achieve the expected extraction performance. Under the optimized separation and capture parameters, the linear range and limit of detection for Se(IV) in water sample were 0.050-200 and 0.013 μg/L, respectively. For beer sample, the corresponding values were 0.010-300 and 0.032 μg/L. The developed microextraction approach was successfully utilized to detect trace Se(IV) and Se(VI) in environmental water and beer samples with satisfactory fortified recovery and repeatability. Results well reveal the attractive merits of the established method in the analysis of Se species, including simple preparation of adsorbent, convenient extraction procedure, good sensitivity, high cost-effectiveness, and eco-friendliness.

Salicylic acid alleviates selenium stress and promotes selenium uptake of grapevine.

To determine suitable cultivation measures to enrich selenium (Se) and alleviate the Se stress in fruit trees, the effects of different exogenous salicylic acid (SA) concentrations (0, 50, 100, 150 and 200mg/L) on the growth and Seuptake of grapevine under Se stress were studied. Under Se stress, SA increased the biomass of grapevine to some extent and had a linear relationship with both root and shoot biomass. The chlorophyll content, net photosynthetic rate, transpiration rate, stomatal conductance, and intercellular CO2 concentration of grapevine tended to increase when the concentration of SA was < 150mg/L and decrease when the concentration of SA was > 150mg/L. Different concentrations of SA enhanced the activity of superoxide dismutase, while reducing that of peroxidase. It had no significant effect on the catalase activity of grapevine. SA decreased the content of osmotically active substances in grapevine to some extent. SA also increased the contents of total Se, inorganic Se and organic Se in grapevine to some extent, and had a linear or quadratic polynomial relationship with the total Se contents in both roots and shoots. When the SA concentration was 250mg/L, the total Se contents in the roots and shoots were the highest and increased by 10.41% and 58.46%, respectively, compared with the control. Therefore, exogenous SA could promote the growth andSe uptake of grapevine under Se stress, with 250mg/L serving as the most effective concentration.

Biofortification of selenium in black soldier fly (Hermetia illucens) prepupae reared on seaweed or selenium enriched substrates

Selenium (Se) is an essential trace element for livestock. The element can be supplemented to feed in inorganic or organic Se forms, where the chemical form in the diet affects the accumulation of Se in animal tissues. Insects are known to be natural bioaccumulators of different nutrients, but no studies have so far looked up on the capacity of insects to be biofortified with Se, as a potential future source for Se in feed. In this study, black soldier fly (BSF, Hermetia illucens) larvae were reared on three different substrates: (1) a control substrate (CTR diet) of plant-ingredients (Gainesville diet); (2) Ascophyllum nodosum diet (AN30%), with 30% substitution of the alfalfa meal with the brown algae; and (3) a Se diet, where the CTR diet was fortified with 0.3 mg/kg of Se. All experiments were carried out under dark condition, at 25 °C with 70% relative humidity for two weeks, and the final BSF prepupae were analysed for Se, metals and minerals, and Se species. The mean total Se content in the prepupae reared on Se dietary group was over five times higher compared to the CTR group, whereas lower Se levels were detected in AN30% dietary group. Se speciation analyses showed that organic selenomethionine (SeMet) was the major Se species present, both in CTR and AN30% group. For the Se group, SeMet was accounting for 54% of the total Se. The levels of SeMet were higher in the Se group compared to the CTR group, indicating that BSF prepupae are able to convert inorganic Se to organic Se. The overall results show that the substrates hereby studied affect the total Se and Se species, as well as the levels of other elements, in the BSF prepupae.

Selenium Accumulation and Speciation in Chickpea (Cicer arietinum) Impacted by S in Soils: Potential for Biofortification

Dietary selenium (Se) deficiency is a well-known global problem originating from food crops grown in Se-deficient soil. Agronomic Se biofortification is one of the suitable options to minimize Se deficiency. Sulfur (S) is chemically similar to Se, and the role of S on the uptake and transformation of Se in grain has not been resolved. Considering this, our study examines the influence of S on the speciation and accumulation of Se in two chickpea cultivars (Amber and PBA sheamer) grown in Se-deficient soil under glasshouse conditions. Two doses of S (0 and 14 mg kg–1) as sulfate and three doses of Se (0, 1, and 2 mg kg–1) as selenate (SeVI) were used in a randomized factorial design. The addition of SeVI increased the Se content in grain in both cultivars compared to the control treatment. Speciation of Se analysis in grain showed that most (85%) of the Se accumulated in chickpea grain in the organic forms of Se as SeCys and MeSeCys. At 2 mg/kg Se addition, the biomass and grain yield was significantly reduced (P < 0.01), while S addition tended to increase the yield. Inorganic Se was below 15%, primarily as SeVI. PBA Sheamer, a desi type and widely grown chickpea cultivar, showed the most significant proportion of organic Se species, SeCys (57%) and SeMeCys (40%). Application of S contemporarily with Se showed increased SeMeCys production in the grain of PBA Sheamer cultivar. These findings indicated that the accumulation and speciation of Se in chickpea grain was dependent on both Se and S fertilization.

Effects of inorganic and organic selenium intervention on resistance of radish to arsenic stress

Arsenic (As) pollution, a potential threat for human health, in vegetables is one of the primary sources of As intake by the human body. In the Pot Experiment, the As content, physiological index and antioxidant enzyme activity of radish were determined. The results demonstrated that the order of As concentration in radish tissues was roots &gt; stems &gt; leaves. Organic selenium (Se) can inhibit the absorption of arsenic in radish more effectively than inorganic Se. The application of organic Se and low concentration of selenite (Se(IV)) significantly enhanced the stress resistance of radish for increasing superoxide dismutase and peroxidase activity, increasing soluble protein, chlorophyll and proline content, and reducing malondialdehyde content. In contrast, the high concentration of Se(IV) and selenate (Se(VI)) treatment group demonstrated stress and toxicological effects on radish. This study provides an idea for further research on the remediation mechanism of Se to As toxicity and provides a reference for the adoption of Se fertilizer in agriculture.

Influence of selenium on the mycelia of the shaggy bracket fungus, Inonotus hispidus.

Selenium (Se) is a needed trace element for animals and humans. Many fungi have effective mechanisms to acquire, transform and accumulate Se in organic form. In this study, the effects of inorganic Se (sodium selenite) on the medicinal fungus Inonotus hispidus was investigated. Inonotus hispidus was capable of tolerating up to 3.85 mmol L-1 selenite, at which ~85% growth inhibition was seen, with 50% growth inhibition occurring at ~1 mmol L-1 selenite. Growth in 0.29 mmol L-1 Se resulted in I. hispidus mycelium with 115 times higher Se levels compared to growth in standard media, and an organic Se content of 86% to total Se content. The influence of Se accumulation on morphological features of I. hispidus were examined by microscopic and scanning electron microscopic observation. These data revealed significant shrinkage and deformations of I. hispidus hyphae with decreased branching and collapse of clamp connections under higher Se stress. However, conidial production in I. hispidus increased dramatically. The influence of Se on mycelial growth could be recovered by reinoculation in standard media. Se accumulation had only minimal impacts on the yield of the potential selenocompounds such as amino acids, proteins and polysaccharides. By contrast, Se-enriched I. hispidus mycelium was of higher quality due to reduction in crude fat and total ash contents. These data provide basic and applied information on the feasibility of producing selenized I. hispidus as an enriched and better quality product. © 2021 Society of Chemical Industry.

Dietary supplementation of nano-selenium eliminates the negative effects of long-term ivermectin injection on growth and reproductive performance of female rabbits

Objective:We investigated the effects of a source of selenium [inorganic or nano-selenium (nano-Se)] on female V-line rabbits with or without injection of ivermectin (IVM).Material and Methods:Eighty four rabbits (12 weeks old) were randomly divided into 4 groups of 21 rabbits each with the basal diet supplemented as per the following treatments: G1 (control): inorganic Se at 0.3 mg/kg diet with no IVM injection; G2: inorganic Se with IVM injection; G3: nano-Se with no IVM injection; and G4: nano-Se with IVM injection. IVM was injected subcutaneously at 0.2 mg/kg body weight starting when the does were 14 weeks old and repeated weekly for five consecutive weeks.Results:Replacement of inorganic Se with nano-Se improved body weight and total body weight gain, total feed intake, average feed conversion ratio, and reproductive performance (age at puberty, number of service/conception, conception rate, number of kits/litter, and litter weight at birth). Similarly, sexual activity of does, serum estrogen levels, and serum levels of antioxidants (glutathione reduced, catalase, and malondialdehyde) increased in nano-Se-supplemented groups. Ivermectin treatment in inorganic Se-supplemented groups was detrimental to growth and reproductive performance, while these parameters improved in IVM-treated and nano-Se-supplemented groups.Conclusion:Nano-Se mitigated the negative effects of IVM treatment on the growth and reproductive performance of does.

The Health Risk for Consumers Under Heavy Metal Contamination Scenarios in Future: Reduce Bioaccumulation of Cd Pollutants in Estuary Mud Crab (Scylla Paramamosain) Through the Antagonism of Organic or Inorganic Se

The Health Risk for Consumers Under Heavy Metal Contamination Scenarios in Future: Reduce Bioaccumulation of Cd Pollutants in Estuary Mud Crab (Scylla Paramamosain) Through the Antagonism of Organic or Inorganic Se