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Rotifers are widely used as a live prey for finfish larvae, although their content in minerals such as selenium and zinc is lower than in fish. In the present study, mixed microalgae (i.e., Isochrysis aff. galbana and Nannochloropsis oculata) were enriched with different amounts of Se and Zn either alone (45, 90, and 135 mg L−1 of Zn, 60, 120, and 180 mg L−1 of Se) or mixed (22.5, 45, and 90 mg Zn L−1 and 30, 60, and 120 mg Se L−1). The content of minerals in the microalgae was analysed after 1 and 3 h enrichment and their effect on the growth and mineral composition of the rotifer. Based on the results, 1 h enrichment time and 90 and 120 mg L−1 of Zn and Se, respectively, resulted in the highest amount of Se and Zn in enriched microalgae. The maximum Zn content was detected in the rotifers fed 90 mg L−1 Zn and 90 mg L−1 Zn +120 mg L−1 of Se, but the maximum Se was observed in rotifers fed with 120 and 180 mg L−1 Se. Thus, Se- and Zn-enriched rotifers can be used as a mineral delivery method to cover marine fish larvae nutritional requirements. info:eu-repo/semantics/acceptedVersion

The bioconversion of selenium in the form of sodium selenite (Na2 SeO3 ) (SeIV) or sodium selenate (Na2 SeO4 ) (SeVI) to organic form by Lactobacillus casei (L. casei) was investigated in vitro. MRS media was supplemented with 1, 2, 5, 10 or 20 ppm of Se, inoculated with 2% starter culture with about 105 cfu/ ml of L. casei and then incubated up to 24 hrs at 37o C. Increasing of selenite “Se(IV)” concentrations in the media markedly reduced the bacterial growth compared to selenate “Se(VI)” indicating cytotoxic effect of selenite. The media supplemented with 5 ppm or more of Se(IV) became reddish after 24 hr of incubation as a result of the formation of 100-200 nanometer particles of selenium (SeNPs). Se speciation of the cultured media supernatants and its corresponding cell fractions was carried out by HPLC-ICP-MS technique. The bioconversion rate of Se to organic form by L. casei was extremely higher in Se(IV) than Se(VI) in both fractions, however the media supernatant contained the highest content. Increasing the media Se content resulted in gradual increase of organic Se concentration in both cells and supernatant fractions. The medium supplemented with 1 ppm Se(IV) was completely depleted from the inorganic Se as it completely converted to organic form. Although the cell fractions from all Se(VI) supplemented media contained only organic Se, the media supernatant contained significant residual amount of the inorganic form. Our results demonstrate the ability of L. casei to convert Se(IV) or Se(VI) up to 20 ppm to organic form(s) either in the cultured media or inside the bacterial cells. However, Se(IV) but not Se(VI), at a limit concentration of 1 ppm, was completely converted and accumulated in an organic form in the cell fraction and the cultured medium.

Background Selenium is an essential trace element for life. It plays an irreplaceable role in delaying human aging, improving immunity, preventing cardiovascular diseases and treating Keshan disease. There are inorganic selenium and organic selenium in nature. Selenopolysaccharide plays an important role in the selection of selenium supplements, but the selenium content of selenopolysaccharide is generally low, so there are some regional limitations in obtaining selenopolysaccharide. Scope and approach In order to improve the biological activity of selenium polysaccharides, organic selenium polysaccharides with high selenium content have become one of the hot spots of research and development. Selenium polysaccharide has a variety of biological activities, such as anti-tumor, anti-virus, improving immunity and so on. Key findings and conclusions The research status of selenium polysaccharide at home and abroad in recent years was reviewed, including the source, preparation and biological activity of selenium polysaccharide. The future development and utilization of selenium polysaccharides in the field of health care or medicine is of great significance.

Inorganic selenium, the most common form of harmful selenium in the environment, can be determined using electrochemical sensors, which are compact, fast, reliable and easy-to-operate devices. Despite progress in this area, there is still significant room for developing high-performance selenium electrochemical sensors. To achieve this, one should take into account (i) the electrochemical process that selenium undergoes on the electrode; (ii) the valence state of selenium species in the sample and (iii) modification of the sensor surface by a material with high affinity to selenium. The goal of this review is to provide a knowledge base for these issues. After the Introduction section, mechanisms and principles of the electrochemical reduction of selenium are introduced, followed by a section introducing the modification of electrodes with materials interacting with selenium and a section dedicated to speciation methods, including the reduction of non-detectable Se(VI) to detectable Se(IV). In the following sections, the main types of materials (metallic, polymers, hybrid (nano)materials…) interacting with inorganic selenium (mostly absorbents) are reviewed to show the diversity of properties that may be endowed to sensors if the materials were to be used for the modification of electrodes. These features for the main material categories are outlined in the conclusion section, where it is stated that the engineered polymers may be the most promising modifiers.

This study aims to investigate the effects of different selenium (Se) sources on the growth performance of Chinese broilers and provide a scientific rationale for adding Se additives to broiler feed. Relevant studies that meet standard inclusion criteria were identified and extracted from China National Knowledge Infrastructure and Wanfang and Chinese Scientific Journal (VIP) databases. A total of 9 studies with 539 subjects were included. A meta-analysis was performed with STATA15.0 to estimate the combined standardized mean difference (SMD) with a 95% confidence interval (95% CI). Heterogeneity test of articles was examined by Q-test, and the results showed that P values of feed conversion ratio, average daily gain (ADG), and average daily intake were all less than 0.05, suggesting a strong heterogeneity among the selected literature. Therefore, the random effect model is selected to calculate the SMD of the three indexes. The combined SMDs (95% CI) of feed:gain, ADG, and average daily feed intake (ADFI) were −0.39 (−1.03, 0.25), 0.26 (−0.29, 0.81), and −1.45 (−3.09, 0.20), respectively, and the P values were all less than 0.05. This study shows that the absolute differences in the growth performance (feed:gain, ADG, and ADFI) of broilers fed with either organic or inorganic Se supplements at the same dose were quite small. The P values of Egger’s test were 0.770, 0.089, and 0.426, respectively, for the above indexes, showing no significant publication bias. Sensitivity analysis ensured the stability and reliability of the results. In summary, the effects of organic and inorganic Se in feed on the growth performance of broilers are statistically equal.

The present experiment aimed to compare toxic effects of dietary organic or inorganic selenium (Se) and to predict of Se intake and tissue Se concentrations in broiler chickens based on feather Se concentrations. A total of four hundred twenty 7-day-old Ross 308 male broiler chicks were allotted to 1 of 7 dietary treatments in a completely randomized design. Each treatment had 6 replicates with 10 birds per replicate. Organic Se (selenium yeast) or inorganic Se (sodium selenite) was added to the basal diet at the levels of 5, 10, or 15 mg/kg Se. All experimental diets were fed to birds on an ad libitum basis for 28 d. Results indicated that a significant interaction (P

The total selenium content of selenium-enriched agricultural products was determined by inductively coupled plasma mass spectrometry after microwave digestion. The total selenium content in the tes...

Aims Most crops are supplemented with selenium (Se) through the exogenous addition of inorganic selenium fertilizer. There is a lack of in-depth research on organic selenium fertilizers. Meanwhile, the dosage range between human selenium deficiency and selenium toxicity is narrow, so the selenium content of agricultural products needs to be controlled within a reasonable interval. Methods W e analyzed and compared the Se accumulation and speciation in rice during three different growth stages (late tillering stage, initiate heading stage, and full heading stage) using three selenium fertilizers, selenite, fermented Se, and potassium Selenocyanoacetate (Se-AAF) via the foliar application. Results The selenium content in rice sprayed with organic selenium fertilizer was controlled in the relatively safe range and met the human selenium supplement requirement compared to the sprayed sodium selenite, which was too high of a dose. The percentage of organic Se and protein Se in brown rice was found to be similar in all three Se fertilizers. The highest organic selenium content of 91.57% was found in the grain of rice at the full heading stage by spraying Se-AAF. The main Se species in the grain was selenomethionine (SeMet), which reached 80% of the total selenium. Se-methyl selenocysteine(SeMeCys) was found only in Se-AAF. The grain quality showed that all three Se fertilizers increased the consistency of gelatinization. Conclusions Appropriately delaying the spraying time and selecting organic Se fertilizer as the Se source can help to produce green and safe selenium-rich rice.

The ability of several plants to accumulate and transform inorganic selenium forms into its bioactive organic compounds has important implications for human nutrition and health. Selenium in plant food can be found in several chemical forms, which have huge difference in function and bioavailability. Therefore, it is very important to analyze them to ensure food quality and to evaluate their impact on health. Liquid chromatography operating in different modes (size exclusion, reverse phase, ion exchange or hydrophilic interaction) and coupled to sensitive inductively coupled plasma mass spectrometry detection is the most frequently used technique for selenium speciation analysis. The main purpose of this review is to provide an update on the recent literature concerning the strategies for selenium speciation in plant materials. This survey will attempt to cover the state of-the art since 2010.

The biosynthesis of inorganic selenium into seleno amino acids has been studied in recent years. Thus, it has been reported that Saccharomyces cerevisiae bioaccumulates selenium from the metabolism of inorganic selenium. Based on the studies conducted, several authors have proposed a biotransformation metabolism of selenate into selenomethionine or selenocysteine. However, the pathway in different yeast is unknown. Therefore, and given the relevance of Saccharomyces boulardii as probiotic yeast, this study aims to propose the pathway used by S. boulardii to biosynthesize inorganic selenium into organic species. A comparative in silico study was performed for Saccharomyces boulardii ASM141397V1 with the genome-scale metabolic model of Saccharomyces cerevisiae S288C. Orthologous genes were identified using BLASTp of NCBI. In addition, a circular representation was done using CIRCOS software. The metabolic pathway for the assimilation of selenium was proposed based on the results obtained

This chapter is devoted to selenium and its role in organism. Selenium has been proved as an essential element for animals and humans. Perception of its role changed from the toxic toward essential element as in the last decade its importance has been described through its biochemical functions. Selenium can be found in the environmental components such as air, water, soil, as well as in living organisms. Plants have crucial role especially in transformation of inorganic selenium forms into organically bound. The natural source of selenium for plants is usually soil, and from the soil solution, selenium is absorbed and metabolized into organic compounds such as seleno-amino acids which can be used as a building materials for the higher structures, especially selenoproteins. Selenium enrichment of crops has been briefly described with the examples from the practice across the world.

Ninety-six male goslings were allocated and assigned to treatment using a completely randomized design. Dietary treatments included a basal diet consisting of corn, wheat, and soybean meal with either no additional selenium (CON), 0.3 mg/kg of inorganic selenium (I-Se, sodium selenite), or 0.3 mg/kg of organic selenium (O-Se, selenium-enriched yeast). After a 56-day feeding period, geese were slaughtered on a common ending day and two geese per pen (n = 24) were used for the analyses conducted in this study. Meat (equal portions of the breast and thigh meat) and liver were collected and evaluated for proximate composition, fatty acid profile, pH, phenolic content, thiobarbituric acid reactive substances (TBARS), and total volatile basic nitrogen (TVB-N) over a 9-day storage period at 4 &deg, C. The meat and liver samples from geese supplemented I-Se or O-Se had greater (p &lt, 0.01) lipid content compared with geese not supplemented with additional selenium. At the conclusion of the 9-day storage period, meat and liver samples from geese supplemented I-Se or O-Se had lower (p &lt, 0.05) pH values, greater (p &lt, 0.05) phenolic content, lower (p &lt, 0.05) TBARS values, and lower (p &lt, 0.05) TVB-N compared with geese not supplemented with additional selenium (CON).

The Allium genus vegetables are of special interest since being potentially sources for selenium. In this study, the metabolization of selenite and selenate fortification at low and high levels in hydroponically cultivated Allium porrum (Leek) was investigated. The total Se analysis of nutritional solutions which was used in cultivation medium revealed that leeks had potential to accumulate Se above over 1000 mg/kg without any growth disturbance which was proved by comparing dry masses of control group with the ones fortified by Se species. Speciation analyses performed in edible parts which are leaves and stems showed that approximately 90% of total selenium was biotransformed into organo-selenium species in which MeSeCys and SeMet were found to be the most dominant in Se(IV) fortified leeks. However, selenate was found to be the most abundant species in edible parts of selenate fortified leeks especially at high levels. Although bioavailability rate of total selenium in selenate fortified leeks was found to be higher, lower amount of inorganic selenium and higher amount of MeSeCys were found to be bioavailable in Se(IV) fortified.

Se-methylseleno- l -cysteine ( l -SeMC) is a natural source of organic selenium for humans. Although it has a structure similar to that of l -Cysteine ( l -Cys), its anti-inflammatory properties and possible underlying mechanisms have not been explored. Here, we compared the anti-inflammatory activities of inorganic selenium (selenite), l -Cys, and l -SeMC in lipopolysaccharide (LPS)-activated RAW 264.7 murine macrophages and focused on the related molecular and biochemical events. The results showed that, anti-inflammatory activity of l -SeMC was much stronger compared to both individual l -Cys treatment and l -Cys/selenite combinations. The organic form of selenium may play a crucial role in the effects of l -SeMC. Further study confirmed that l -SeMC suppressed the RNA expression of iNOS, TNF-α, IL-1β, IL-6, COX-2, and MMP-9, as well as the release of NO, TNF-α, IL-6, IL-12p70, COX-2, and PGE2 from LPS-activated RAW264.7 macrophages in a concentration-dependent manner. Moreover, l -SeMC prevented LPS-induced changes in cell morphology. l -SeMC concentrations between 50 and 200 μM exhibited an anti-inflammatory effect closed to that exhibited by 20 μM dexamethasone. Our results demonstrated that l -SeMC effectively inhibited the activation of RAW 264.7 macrophages induced by LPS, and suggested that l -SeMC could be a potential functional food component for the prevention or treatment of inflammatory diseases.

A fit for purpose analytical protocol was designed towards searching for low molecular weight seleno-compounds in sprouts. Complementary analytical techniques were used to collect information enabling the characterization of selenium speciation. Conceiving the overall characterization of the behavior of selenium, inductively plasma optical mass spectrometry (ICP-MS) was used to determine the total selenium content in entire sprouts as well as in selected extracts or chromatographic fractions. Then, high-performance liquid chromatography combined with ICP-MS (HPLC-ICP-MS) was used to evaluate the presence of inorganic and organic seleno-compounds, with the advantages of being very sensitive towards selenium, but limited by available selenium standard compounds. Finally, ultra-high performance liquid chromatography electrospray ionization triple quadrupole mass spectrometry (UHPLC-ESI-QqQ-MS/MS) and UHPLC-ESI-Orbitrap-MS/MS were used for the confirmation of the identity of selected compounds and identification of several unknown compounds of selenium in vegetable sprouts (sunflower, onion, radish), respectively. Cultivation of plants was designed to supplement sprouts with selenium by using solutions of selenium (IV) at the concentration of 10, 20, 40, and 60 mg/L. The applied methodology allowed to justify that vegetable sprouts metabolize inorganic selenium to a number of organic derivatives, such as seleno-methylselenocysteine (SeMetSeCys), selenomethionine (SeMet), 5&prime, seleno-adenosine, 2,3-DHP-selenolanthionine, Se-S conjugate of cysteine-selenoglutathione, 2,3-DHP-selenocysteine-cysteine, 2,3-DHP-selenocysteine-cysteinealanine, glutathione-2,3-DHP-selenocysteine, gamma-Glu-MetSeCys or glutamyl-glycinyl-N-2,3-DHP-selenocysteine.

SUMMARY The present study was planned to explore the effects of different selenium-supplemented diets on production performance in 4 varieties of Aseel chicken, including Lakha (LK), Mushki (MS), Peshawari (PW), and Mianwali (MW). The selenium (Se) from Se-enriched yeast (SY) and sodium selenite (SS) was supplemented into a corn-soybean meal basal diet at 0.3 mg/kg, whereas control diet had no supplemental Se. In total, 84 adult molted Aseel hens (50 wk old), 21 from each variety, were randomly assigned to 12 treatment groups in a 3 × 4 factorial arrangement of 3 Se diets (organic, inorganic, and control) and 4 Aseel varieties (LK, MS, PW, and MW), under a randomized complete block design (RCBD). Each treatment had 7 replicates with individual hens per replicate. Feed intake (FI), body weight (BW), egg production (EP), egg weight (EW), egg mass (EM), FCR/dozen eggs, and FCR/kg egg mass parameters were evaluated. The results indicated that the hens fed organic Se-supplemented diet showed greater (P

Selenium nanostructures are characterized with high activity and antibacterial properties. Selenium nanoparticles, received by the biotechnological method using microorganisms are not toxic and free from admixtures of other toxic elements. For getting selenium nanostructures, there was set a problem of development of the biotransfrormation technology of inorganic selenium by the culture Lactobacillus acdophilus, strain 412/307 from the museum of the Department of Biochemistry, Microbiology and Physiology of Nutrition Odessa National Academy of Food Technologies (Ukraine). Selenium nanostructures are the side product in the process of selenocysteine formation. There was realized the study of the influence of the sodium selenite concentration on the growth speed and generation duration of lactobacteria on MRS medium for determining the main technological parameters. There was determined the quantitative content of accumulated selenium at different initial concentrations of sodium selenite in the medium. The important part of the elaborated technology is destruction of cellular walls of microorganisms for removal selenium nanoparticles. There was studied the influence of different physical-chemical factors of cells’ destruction. There was offered to use the combined influence of saline acid, freezing and microwave field for destructing cellular walls of lactobacteria biomasses. There is presented the scheme of the technology of getting “Nanoselenium” and given physical-chemical parameters of the received product.

Anthropogenic activities such as mining, industrialization and subsequent emission of industrial waste, and agricultural practices have led to an increase in the accumulation of metal(loid)s in agricultural soils and crops, which threatens the health of people; the risk is more pronounced for individuals whose survival depends on food sources from several contaminated regions. Selenium (Se) is an element essential for the normal functioning of the human body and is a beneficial element for plants. Se deficiency in the diet is a common issue in many countries around the world, such as China and Egypt. >40 diseases are associated with Se deficiency. In practice, Se compounds have been applied through foliar sprays or via base application of fertilizers to increase Se concentration in the edible parts of crops and to satisfy the daily Se intake. Moreover, Se at low concentrations has been used to mitigate the toxicity of many metal(loid)s. In this review, we present an overview of the latest knowledge and practices with regards to the utilization of Se to reduce the uptake/toxicity of metal(loid)s in plants. We have focused on the following issues: 1) the current status of understanding the mechanisms of detoxification and uptake restriction of metal(loid)s regulated by Se; 2) the optimal dose and speciation of Se, and stage of plant growth that is optimal for application; 3) the differences in the efficiency of different application methods of Se including seed priming, base application, and foliar spray of Se fertilizers; 4) the possibility of using Se along with other methods to reduce multiple metal(loid) accumulation in crops; and 5) potential risks when Se is used to reduce metal(loid) accumulation in crops.

Selenium, a metalloid, commonly known for its essentiality has emerged out as a water pollutant of concern for environmentalist due to its presence in natural water resources above the permissible limit. The high level of selenium in the environment poses severe health and ecosystem threats, therefore, its monitoring in water is of paramount concern. The present contribution summarizes and critically analyzes the field promising techniques, in particular, voltammetry and optical approach, for selenium quantification in water. The role of sensor material (organic fluorophores, colorimetric dyes and quantum dots), electrode surface modifiers (Hg, Bi, polymers, nanomaterials, etc.), chelators, etc., to overcome various challenges and achieve better sensor performance in terms of detection limit, range, reproducibility, stability, selectivity, sensitivity, and so forth are critically discussed. To end with, the possible future developments are discussed towards the realization of a cost-effective & field deployable monitoring device for on-site selenium analysis.

This study aimed to evaluate effects of supplementing the diets of laying hens with different sources of Se and different levels of flaxseed on egg Se concentration, yolk antioxidant properties and immune response. In a completely randomized design, 384 Hy-Line W-36 hens (aged 50 weeks) were assigned to a 3 × 4 factorial arrangement, comprising four replicates of eight hens. For 10 weeks, the birds were fed one of three basal diets containing 0, 50, and 100 g/kg of flaxseed and regular Se content from mineral premix, supplemented with no additional Se (SN) and 1 mg/kg of Se from sodium selenite (SS), Se-enriched yeast (SY), and hydroxy selenomethionine (SOH). The greatest Se concentration in the yolk was observed in diets containing organic Se sources. The SOH diet produced the greatest albumen Se concentration, followed by SY, and then SS. Using any Se supplementation improved glutathione peroxidase activity and total antioxidant capacity, compared with SN. However, superoxide dismutase activity and malondialdehyde were not affected by Se supplementation. Cell-mediated immune response was improved by Se supplementation, especially SS. Antibody response against sheep red blood cell (SRBC) was not affected by Se source, except that IgM was greater in the hens that received SS and SY. Neither flaxseed supplementation, nor its interaction with Se source was significant for any trait. Thus, supplementation of diets with 1 mg/kg Se, especially from organic sources, enriched the egg and improved some yolk antioxidant properties and immune system function. Supplemental flaxseed did not influence any measured traits. Keywords: egg albumin, egg yolk, Immune function, inorganic selenium, organic selenium

The aim of the present study was to assess the effects of selenium feed supplements on the functional properties of eggs. The hens in experimental groups were fed diets supplemented with 0.2 mg/kg selenium from sodium selenite (Group 1), selenium-enriched yeast (Group 2), synthetic L-selenomethionine (Group 3), or hydroxy analog of selenomethionine (Group 4). The Control Group (Group C) was fed with basal feed without supplementation. The highest values of albumen gel firmness were shown in Group C eggs; differences with all experimental groups were significant (p

Selenium is an essential trace element that is involved in the synthesis of various selenoproteins in higher animals including humans. Twenty five selenoproteins have been identified in humans. These selenoproteins have various physiological functions. Organic selenium is safer than inorganic selenium and can be used as a nutritional supplement for people who live in selenium-deficient areas. Supera-nutritional intake of selenium has been claimed to prevent cancer, however, consistent clinical results are lacking. At this time, the use of selenium-rich foods by those in selenium-deficient areas might be the safest and best recommendation. This is a brief overview of the requirements for selenium, the selenium enrichment process in plants and animals, and the preparation of typical selenium-rich foods so as to provide some help for the application and development of selenium fortified products.

The aim of this study was to compare the effects of two Se sources on the early lactation of native goats, on nutrient digestibility, as well as nitrogen and energy status of Iranian native goats. Twenty-one native goats aged, approximately 41 ± 9 months and having body weights of 46 ± 8 kg were selected for the experiment. The goats were randomly divided into three groups with an equal number of goats. One group was supplemented with Selemax 2000® as the organic selenium (OS), the second group received diluted sodium selenite as the inorganic selenium, while the third group received no supplementation and served as the control group (C). The results of this research showed that the selenium supplement did not have a significant effect on nutrient digestibility (apart from crude fat) (P > .05) but, the dry matter, organic matter and crude protein intake significantly increased. However, faecal N, urinary N, total N production and energy status were affected by the treatments (P

The effect of selenium supplementation in finishing broiler diets on meat quality was studied. A corn soya based diet was supplemented with 0.3 ppm of Se from an organic (Seleno methionine; Se-Met) or inorganic source (sodium selenite; Se-Na) and offered to Rossmale chickens from thirty five to fifty two days old. Body weight and feed consumption were recorded during the experimental period. Immediately post sacrifice liver was removed and weight was recorded. The liver glycogen and lactate content was measured. Carcass yield and abdominal fat were determined. At 24 hours post mortem, pHu, colour L*, a*, b*, H°, C*, and drip loss of the Pectoralis and Gastrocnemius muscles were determined. Se-Met supplementation significantly decreases daily food intake. Se-Na significantly increases liver glycogen and lactate content at 3 minutes post mortem. Se-Met and Se-Na significantly increase pHu as compared to the control diet. Also a Se-Met provoked a darker (lower L*) and a redder (higher a*) and a decreased tone (lower H°) in Pectoralis. Se-Met and Se-Na significantly decrease the drip loss in Pectoralis and Gastrocnemius at 24 hours post mortem. We conclude that selenium supplementation decreases food intake and improves meat quality by improving colour and decreasing drip loss, likely by a modulation of reserve of glycogen in liver. The difference among the organic and inorganic sources is not clear and requires further investigation.

Selenium is a trace element essential for human health that has received considerable attention due to its nutritional value. Selenium’s bioactivity and toxicity are closely related to its chemical form, and several studies have suggested that the organic form of selenium (i.e., selenomethionine) is more bioavailable and less toxic than its inorganic form (i.e., sodium selenite). Probiotics, especially Bifidobacteriium and Lactobacillus spp., have received increasing attention in recent years, due to their intestinal microbial balancing effects and nutraceutical benefits. Recently, the bioconversion (a.k.a biotransformation) of various bioactive molecules (e.g., minerals, primary and secondary metabolites) using probiotics has been investigated to improve substrate biofunctional properties. However, there have been few reports of inorganic selenium conversion into its organic form using Bifidobacterium and Lactobacillus spp. Here we report that the biosynthesis of organic selenium was accomplished using the whole cell bioconversion of sodium selenite under controlled Bifidobacterium bifidum BGN4 culture conditions. The total amount of organic and inorganic selenium was quantified using an inductively coupled plasma-atomic emission spectrometer (ICP-AES). The selenium species were separated via anion-exchange chromatography and analyzed with inductively coupled plasma-mass spectrometry (ICP-MS). Our findings indicated that the maximum level of organic selenium was 207.5 µg/g in selenium-enriched B. bifidum BGN4. Selenomethionine was the main organic selenium in selenium-enriched B. bifidum BGN4 (169.6 µg/g). Considering that B. bifidum BGN4 is a commercial probiotic strain used in the functional food industry with clinically proven beneficial effects, selenium-enriched B. bifidum BGN4 has the potential to provide dual healthy functions as a daily supplement of selenium and regulator of intestinal bacteria. This is the first report on the production of organic selenium using B. bifidum spp.

OBJECTIVE This study was conducted with the objectives to examine the impacts of inorganic selenium (Se) and different types and levels of organic selenium on the serum and tissues Se status and antioxidant capacity in broiler breeders. METHODS Five hundred and forty 48-wk-old Lingnan Yellow broiler breeders were randomly assigned to 6 dietary treatments, provided same basal diet (0.04 mg/kg of Se) with 0.15 mg/kg, or 0.30 mg/kg of Se from sodium selenite (SS) or from selenium-enriched yeast (SY) or from selenomethionine (SM). The broiler breeders were slaughtered after an 8-wk experiment. RESULTS The results showed that SM was better than SY and SS, 0.30 mg/kg level was better than 0.15 mg/kg level in Se deposition (p

Selenium is one of the most prominent essential trace elements for humans. Generally, the major supply of selenium results from the regular nutrition. In the regular diet almost all selenium exists in the form of organic compounds, e.g. as selenomethionine and other selenoamino acids. In contrast, special exposure by functional food, environmental contamination or occupational exposure may occur partly or mainly in the form of inorganic selenium compounds and elemental selenium, which differ in absorption, distribution, metabolism and elimination compared to the organic compounds.

Despite the availability of selenium (Se)-enriched trace mineral supplements, we have observed low Se status in cattle and sheep offered traditional inorganic Se supplements. Reasons for this may include inadequate intake or low bioavailability of inorganic Se sources. The objective of this study was to determine whether rumen microorganisms (RMO) alter the bioavailability of Se sources commonly used in Se supplements. Rumen microorganisms were isolated from ewes (n = 4) and incubated ex vivo with no Se (control), with inorganic Na selenite or Na selenate, or with organic selenomethionine (SeMet). Total Se incorporated into RMO and the amount of elemental Se formed were determined under equivalent conditions. Incorporation of Se from Na selenite, Na selenate, or SeMet into RMO was measured as fold change compared with control (no added Se). Incorporation of Se into microbial mass was greater for SeMet (13.2-fold greater than no-Se control) compared with inorganic Se supplements (P = 0.02); no differences were observed between inorganic Na selenate (3.3-fold greater than no-Se control) and Na selenite (3.5-fold greater than no-Se control; P = 0.97). Formation of non-bioavailable, elemental Se was less for RMO incubated with SeMet compared with inorganic Se sources (P = 0.01); no differences were observed between Na selenate and Na selenite (P = 0.09). The clinical importance of these results is that the oral bioavailability of organic SeMet should be greater compared with inorganic Se sources because of greater RMO incorporation of Se and decreased formation of elemental Se by RMO.

This study evaluated the effect of dietary organic and inorganic selenium supplementation on chemical, mineral and fatty acid composition of ostrich meat. Forty ostriches were raised in two groups (OSe and IOSe, diets supplemented with an organic form and an inorganic form of selenium, respectively). The form of selenium had no influence on chemical composition of ostrich muscle. Although, there were no significant differences in total content of SFA, MUFA and PUFA, the content of LA and EPA was higher in the muscles of ostriches which were put on a diet supplemented with an organic form of selenium, what resulted in lower n-6/n-3 fatty acids ratio in OSe group (9.99) in comparison to IOSe group (11.70). The results of the study indicate that dietary organic selenium supplementation improves the quality of the ostrich meat as related to the health promoting properties (LA, EPA and selenium content) of meat.

Selenium compounds, in both inorganic and organic forms have been explored for development as radioprotectors, agents used to minimize the deleterious effects of radiation. Most of the research in this direction has been focused on inorganic selenium, including several clinical studies where selenium supplementation yielded useful outcomes in cancer patients undergoing radiotherapy. Since organic selenium is less toxic than inorganic selenium, researchers are now focusing on the development of organoselenium compounds for radioprotection. Both natural and synthetic organoselenium compounds are being examined and one such water-soluble selenium compound, 3,3′-diselenodipropionic acid (DSePA) developed by our group, showed promising activity at pre-clinical stages. These results, along with the current status and future scope of research, are discussed in this chapter.

Trace amounts of selenium (Se) are essential for several organisms, and deficiencies therein have adverse effects on growth, development, and reproduction; this is particularly significant in animals raised for milk and livestock production. To study the effect of Se on Guanzhong dairy goats, their diets were supplemented with different sources (inorganic or organic) and Se concentrations (0.2 or 0.4 mg Se/kg). A non-Se-fortified basal diet served as a negative control, and a sixth treatment group received both inorganic and organic Se sources (0.2 mg Se/kg diet each). Dietary Se supplementation increased milk production, with organic Se being more effective than inorganic Se. Selenium supplementation also increased Se concentration and glutathione peroxidase activity in whole blood, with organic Se more effective than inorganic Se at the same Se concentration. With increasing Se in diets, the Se content in milk increased markedly, reaching a plateau value at day 30 in all groups, and organic Se (0.4 mg/kg diet) had the best effect. In addition, dietary Se sources and concentrations markedly affected Se concentrations in different tissues and organs. Thus, organic Se supplementation of a basal diet at 0.4 mg/kg is practically applicable for Se-enriched milk and meat production in Guanzhong dairy goats.

Two hundred-forty 3-weeks-old Aseel birds from Lakha, Mushki, Peshaweri and Mianwali varieties of indigenous Aseel were chosen (60 birds/variety, 30 males and 30 females) to evaluate the influence of selenium supplements on growth performance. The birds of either sex were divided according to randomized complete block design into A, B and C treatment groups (10 birds/treatment); A and B were experimental, while C was control. Se-enriched yeast (organic selenium) and sodium selenite (inorganic selenium) were supplemented @ 0.3 mg/kg in the basal diets of group A and B, respectively, while, group C was fed without additional selenium. Birds were maintained individually in battery cages from 4-21 weeks. Statistically, the results showed the reduced (P>0.05) feed intake, while enhanced (P£0.05) nutrient utilization for dry matter, crude protein, crude fiber, crude fat and ash; superior feed conversion ratio; higher live final body weight; lower (P£0.05) mortality and rearing cost in Se-enriched yeast fed birds, chiefly in the males of Lakha variety than those received sodium selenite supplemented or control diet. The study concluded that the organic selenium supplement (Se-enriched yeast) had a major influence in improving the overall growth performance of Aseel.

Grains grown in various regions of the United States vary in their innate or natural Se contents. A regional study evaluated the effects of adding inorganic Se (sodium selenite) or organic Se (Se yeast) to diets with differing innate Se contents. A 2 × 2 + 1 factorial experiment evaluating 2 Se sources (organic or inorganic) at 2 Se levels (0.15 or 0.30 mg/kg) in 18 total replicates (n = 360 total pigs). A basal diet was fed without supplemental Se and served as the negative (basal) control. The study was conducted as a randomized complete block design in 9 states (Georgia, Illinois, Kentucky, Nebraska, North Carolina, Ohio, South Dakota, Texas, and Wisconsin) with each station conducting 2 replicates. Pigs were fed from 25 to approximately 115 kg BW. Similar dietary formulations were used at each station, incorporating a common source of trace mineral and Se premixes. Three pigs per treatment in 16 replicates (n = 240) were bled at 55, 85, and 115 kg BW and serum Se and glutathione peroxidase (GSH-Px) activities were determined. Three pigs (n = 260) from each treatment pen were killed at 115 kg BW and issues (liver, loin, and hair) were analyzed for Se. The corn Se content from the various states ranged from 0.026 to 0.283 mg Se/kg while the soybean meal Se content ranged from 0.086 to 0.798 mg Se/kg. Tissue and serum Se concentrations were greater (P < 0.01) when supplemental organic Se was fed, whereas serum GSH-Px was greater (P < 0.01) as Se level increased. There were linear increases (P < 0.01) in loin and quadratic increases (P < 0.01) in liver and hair Se concentrations as dietary Se level increased within each state. There was a source × level interaction (P < 0.01) for each tissue resulting in a greater increase when organic Se was fed. Serum Se and GSH-Px activity increased (P < 0.01) when both Se sources were fed and plateaued at each state at 0.15 mg Se/kg. There was a high and significant correlation between each tissue Se, serum Se, and GSH-Px activity to dietary Se level indicating that those states having greater grain natural Se contents also had greater tissue Se concentrations. These results indicate that a large difference in corn and soybean meal Se concentrations exists between states, that the addition of organic or inorganic Se to these grains increased tissue and serum Se in each state, and that organic Se was incorporated at greater concentrations in the loin, liver, and hair tissues of grower-finisher pigs than inorganic Se.

The aim of this study was to investigate the effects of dietary organic and inorganic selenium (Se) on the growth, Se concentration and meat quality of juvenile grouper, Epinephelus malabaricus. Organic Se (selenomethionine, SeMet) and inorganic Se (sodium selenite, Na2SeO3) were each added to the basal diet of juvenile grouper at 0.3, 0.7, 1.0 and 1.5 mg Se/kg-diet. The basal diet, without Se supplementation, was used as a control. There was a total of 9 experimental diets, and each was fed in triplicate to groups of fish (initial wt: 24.45 ± 0.73 g) in a seawater recirculating system for 8 weeks. Weight gain was significantly (P

Selenium (Se) is shown to be an essential element for poultry nutrition and a great deal of information has been accumulated for the last 20 years indicating that dietary form of Se is a major determinant of its efficiency. Generally speaking, there are two major Se sources for poultry, namely inorganic selenium (mainly selenite or selenate) and organic selenium in the form of selenomethionine (SeMet; mainly as Se-Yeast or SeMet preparations). In this review two main areas are considered in relation to the Se nutrition of breeders. Firstly, it is Se important roles in the maintenance of semen quality and optimal Se status of poultry males and Se is considered to be an important factor in ensuring the fertility of breeding stock. Secondly, Se status of the eggs from breeding birds is of great importance for the maintenance of the antioxidant system of the developing embryo. It is generally accepted that the hatching process is an oxidative stress and improvement in antioxidant defences of the embryo can increase hatchability. It is quite clear that the roles of Se in poultry nutrition and reproduction need new consideration in light of our recent knowledge on the molecular mechanisms of Se action at the cellular and sub-cellular levels. In particular, the discovery and characterisation of a range of new selenoproteins and a better understanding of the relationships between different antioxidants, as important parts of integrated antioxidant system with possibilities for antioxidant recycling in vivo, have yielded new insights in this area. In particular, it should be mentioned that increased levels of Se supplementation are not always beneficial, since selenoprotein synthesis is under the gene control and it reflects the need in these active molecules to deal with various stresses. However, to give a body a chance to affectively respond to environmental challenges by modulating selenoprotein synthesis there should be enough Se reserves available and this an ability of building Se reserves in the body is considered to be the main point in advantages of organic selenium in poultry and farm animal nutrition. A comprehensive analysis of the effects of various forms of dietary Se on its egg concentration, its transfer to the embryonic tissues and physiological consequences of the improved Se status of the progeny chicks are considered.

The aim of the study was to examine the assimilability of organic and inorganic selenium supplied as an additive to pig feed. The influence of both selenium forms on pig slaughter value as well as on the physicochemical and sensory characteristics of meat was also examined (experiment I). An attempt to establish the distribution of selenium in the body of experimental fatteners was made (experiment II). Experiment I was performed on 20 carcasses of crossbred pigs of (Polish Large White × Polish Landrace) × Duroc genotype and experiment II was carried out on 45 samples of longissimus and semimembranosus muscles taken from fatteners of the same genotype (PLW × PL × Duroc). The results obtained indicated that selenium supplementation in the diet had no impact on slaughter performance, meat quality and most physicochemical and sensory characteristics of meat. Selenium was found to have no significant effect on meat colour. The meat water holding capacity (WHC) was lower in the group of pigs fed organic selenium. The highest selenium concentration was found in the semimembranosus muscle of fatteners receiving the inorganic selenium additive.

Effect of selenium(+4) as selenite (Se32−) on two Azospirillum brasilense strains, which occupy different ecological niches (an epiphyte Sp7 and a facultative endophyte Sp245), was studied. The cultures grown in the medium with sodium selenite exhibited intense red coloration. Transmission electron microscopy and X-ray fluorescence analysis revealed accumulation of elementary selenium within the cells of both strains as nanoparticles 50–400 nm in diameter. The ability to reduce inorganic selenium(+4) to elementary selenium (as nanoparticles) has not been previously reported for azospirilla. Our results indicate the possibility to apply Azospirillum strains as microsymbionts for phytoremediation of, and cereal cultivation on, selenium-contaminated soils. The ability of azospirilla to synthesize selenium nanoparticles may be of interest for nanobiotechnology.

The present study aims to determine the effect of dietary Se supplement on Merghoz goats at the last stage of gestation on serum Se, Cu, Zn and Fe status of goats and their kids. Thirty Merghoz does (30 ± 3 kg) were fed the same basal diet containing 0.11 mg Se kg −1 DM and randomly assigned to one of three dietary treatments in a randomized complete block design. Three weeks before the expected kidding, the basal diet was supplemented with 0 (control) or 0.3 mg Se head −1 d −1 in the form of l -selenomethionin (Se-Met) and 0.3 mg Se head −1 d −1 in the form of sodium selenite (SS). Blood samples were collected from the does three weeks before the expected kidding and on the kidding day. Blood samples of newborn kids were also taken from the jugular vein at birth and 7 days of age. The results indicated that the serum concentration of Se increased in supplemented does compared with the control ones. The selenium concentration was also significantly increased in colostrum of treated does ( P P

Selenium is an essential micronutrient in sheep, and deficiency can limit lamb growth and survival. To evaluate how different chemical forms of Se administered to mature ewes at comparative dosages affect ewe and progeny performance, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly with no Se; at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk); with inorganic Na-selenate (8.95 mg Se/wk); or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk, respectively). The treatment period started approximately 2 wk before breeding and lasted for 62.5 wk. Ewes of the no-Se and Se-yeast groups continued treatments for another 21 to 24 wk through a second lambing season. Chemical form or dosage of Se did not affect ewe reproductive performance based on proportion of ewes lambing in each treatment group, or number of lambs born, nursed, or weaned per ewe (all P > 0.10). Ewes receiving the highest supplementation rate of Se-yeast at 24.5 mg Se/wk had higher BCS (scale 1 to 5) at the end of yr 1 (2.95 vs. 2.66; P = 0.05) than ewes receiving Se-yeast at 4.9 mg Se/wk. Performance was better in lambs from ewes receiving Se-yeast at 24.5 mg Se/wk than in lambs from ewes receiving Se-yeast at 4.9 mg Se/wk or no Se. In yr 1, lambs from ewes receiving Se-yeast at 24.5 vs. 4.9 mg Se/wk were heavier at 120 d of age (37.0 vs. 34.2 kg; P = 0.05). In yr 2, lambs from ewes receiving Se-yeast at 24.5 mg Se/wk were or tended to be heavier at 60 d of age than lambs from ewes receiving no Se (21.2 vs. 19.0 kg; P = 0.04) or lambs from ewes receiving Se-yeast at 4.9 mg Se/wk (19.2 kg; P = 0.09). This effect was more pronounced in ewes raising multiple lambs. We conclude that supranutritional supplementation of ewes with Se-yeast at 24.5 mg Se/wk improves lamb growth and ewe health without negatively affecting reproductive performance.

An overview highlighting the anti-cancer potential of (bio-essential) selenium- and tellurium-containing species, with an emphasis on biological targets and mechanisms of action, is presented. Studies thus far have focused on selenium(II) compounds (along with – to a lesser extent – inorganic selenium and selenium nanoparticles) which often successfully exploit the inherent anti-oxidizing ability of selenium. Significantly less work has been conducted in developing anti-cancer tellurium compounds, yet two tellurium(IV) species are proven, clinically, as anti-cancer agents. Given the prevalence of the disease and the accumulated insights into mechanisms of action, the continued development of selenium- and tellurium-containing molecules is an area deserving greater attention. Copyright © 2012 John Wiley & Sons, Ltd.

Selenium was believed to be toxic to animals, however, in 1957, selenium was reported as a dietary vital nutrient. Selenium is available in inorganic and organic forms. In 1974, the Food and Drug Administration (FDA) regulated the supplementation of selenium in poultry diets. In 1994, the National Research Council recognized selenium as a dietary essential nutrient for laying hens. The maximum allowed selenium addition level is 0.30 mg/kg. One of the most common supplements used is sodium selenite (SS), the inorganic selenium source. However, in 2000, the FDA approved the use of the organic source of selenium, Se-enriched yeast (SY) in poultry diets. Selenium has valuable effects on animal immune status, growth parameters, production and reproduction. Experimentally, it has been indicated that SY benefits more than that of SS due to its more bioavailability. Selenium inclusion in food-animal diets has an extra nutritional advantage to human consumers of Se-enriched food-animal products.

Selenium is an essential trace element in the diets which is required for maintenance of health, growth and biochemical-physiological functions. The area covered in this review has been rapidly unfolding in recent years and has already acquired a vast spread. This study presents a concise introductory overview of the effect of organic and inorganic selenium on growth performance, carcass traits, daily egg production, egg quality, Se uptake in various tissues and plasma and plasma glutathione peroxidase activity in animals.

Adequate Se transfer from ewes to lambs is important to prevent Se-deficiency diseases. To evaluate how different chemical forms of Se admin- istered at comparative dosages to mature ewes affect Se status of their lambs, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly (at an amount equal to their summed daily intake) with no-Se (controls); at recommended amounts (4.9 mg of Se/wk) with inorganic Na-selenite, inorganic Na-selenate, or organic Se-yeast; or at supranutritional amounts (14.7 and 24.5 mg of Se/wk) with Na-selenite or Se-yeast for 1 yr. Weekly drenching of Se was effec- tive at increasing (P < 0.002) Se concentrations in ewe colostrum and milk at 30 d of lactation and in improv- ing (P < 0.001) the Se status of lambs (whole-blood and serum-Se concentrations at birth, and skeletal-muscle Se concentrations at 14 d of age). Selenium concentra- tions in lacteal secretions were greater in ewes drenched with Se-yeast (colostrum: 374, 436, and 982 ng/mL at 4.9, 14.7, and 24.5 mg of Se/wk, respectively; milk: 26, 39, 64 ng/mL) compared with ewes drenched with Na- selenite (colostrum: 204, 334, 428 ng/mL; milk: 16, 21, 24 ng/mL), and were also greater (P < 0.001) in their lambs. Selenium concentrations continued to increase (P < 0.001) in lamb whole blood (558 and 695 ng/ mL at 14.7 and 24.5 mg of Se/wk, respectively), serum (126, 183 ng/mL), and skeletal muscle (991, 1,696 ng/ mL) with supranutritional concentrations of Se-yeast, whereas Se concentrations did not differ in whole blood (304, 332 ng/mL), serum (77, 85 ng/mL), or skeletal muscle (442, 482 ng/mg) of lambs from ewes drenched with 14.7 or 24.5 mg of Se/wk of Na-selenite. We con- clude that weekly oral drenching of ewes during ges- tation and lactation with organic Se-yeast results in a more efficient transfer of Se (over a wide range of supplementation rates) from ewe to lamb than does in- organic Na-selenite.

Construction and optimisation of a hyphenated analytical system for high performance liquid chromatography with hydride generation atomic absorption spectrometry detection system are described together with results of its use for investigation of food products. The use of anion-exchange chromatographic column permitted separation of inorganic selenium species Se(IV) and Se(VI) at the limit of detection of 10 ng mL−1 for both species. The analytical system was used for determination of selenium species in dietary supplements available on the Polish market. The content of inorganic selenium species was found not to exceed 50% of its total content, and in the majority of products, the dominant species was Se(IV). In the majority of products, the total contents of selenium were close to those declared by the producers.

A new method was established for the speciation of Se by hydride generation-atomic fluorescence spectrometry. Effective separation of organic and inorganic Se in Se-enriched eggs was achieved by precipitating albumen with trichloroacetic acid. The detection limit for Se was 0.07 μg L−1. The proposed method was successfully applied for the determination of organic and inorganic Se as well as total Se in Se-enriched eggs with the recovery of 90.1–112% and the relative standard deviation (n = 5) of 0.6–3.4%. Se in Se-enriched eggs presents mainly in organic forms, the content of which was three to seven times that of inorganic Se.