Addition Of Sodium Selenite Research Articles

Exploring the lipids, carotenoids, and vitamins content of Rhodotorula glutinis with selenium supplementation under lipid accumulating and growth proliferation conditions

BackgroundRhodotorula glutinis, a specific type of yeast, has been recognised as a superior resource for generating selenium-enriched biomass that possesses exceptional nutritional and functional attributes. The purpose of this investigation was to assess the effect of sodium selenite at different concentrations on lipid and carotenoid synthesis, as well as the growth of R. glutinis.MethodsThe lipid’s fatty acid composition was determined using gas chromatography (GC). The vitamins were detected by high-performance liquid chromatography (HPLC). Transmission electron microscopy was used to detect the structural modification of yeast cells caused by the addition of sodium selenite to the growth medium, as well as the accumulation of elemental selenium in the yeast cells.ResultsThe yeast cells demonstrated the ability to endure high concentrations of sodium selenite under lipid accumulation (LAM) and growth-promoting (YPD) conditions. 25.0 mM and 30.0 mM, respectively, were published as the IC50 values for the LAM and YPD conditions. In both growth media, 1 mM sodium selenite boosted lipid synthesis. Lipid accumulation increased 26% in LAM to 11.4 g/l and 18% in YPD to 4.3 g/l. Adding 1 mM and 3 mM sodium selenite to YPD medium increased total and cellular carotenoids by 22.8% (646.7 µg/L and 32.12 µg/g) and 48.7% (783.3 µg/L and 36.43 µg/g), respectively. Palmitic acid was identified as the most abundant fatty acid in all treatments, followed by oleic acid and linoleic acid. The concentrations of water soluble vitamins (WSV) and fat soluble vitamins (FSV) were generally significantly increased after supplementation with 1.0 mM sodium selenite. TEM examination revealed a significant reduction in lipid bodies accumulation in the yeast cells when sodium selenite was added to lipid-promoting environments. This decline is accompanied by an augmentation in the formation of peroxisomes, indicating that selenium has a direct impact on the degradation of fatty acids. In addition, autophagy appears to be the primary mechanism by which selenium ions are detoxified. Additionally, intracellular organelles disintegrate, cytoplasmic vacuolization occurs, and the cell wall and plasma membrane rupture, resulting in the discharge of cytoplasmic contents, when a high concentration of sodium selenite (20.0 mM) is added. Also, the presence of numerous electron-dense granules suggests an intracellular selenium-detoxification pathway.ConclusionThis study proposes the use of YPD with 1 mM sodium selenite to cultivate selenium-enriched biomass from R. glutinis. This approach leads to heightened lipid levels with higher accumulation of oleic, linoleic and linolenic acids, carotenoids, and vitamins. Hence, this biomass has the potential to be a valuable additive for animal, fish, and poultry feed. Furthermore, explain certain potential factors that indicate the impact of selenium in reducing the accumulation of lipid droplets in R. glutinis during lipogenesis, as detected through TEM examination.

Regulating Effect of Sodium Selenite Addition on Seed Germination and Growth of Pepper (Capsicum Annuum L.) Under Mixed Salt Stress

Regulating Effect of Sodium Selenite Addition on Seed Germination and Growth of Pepper (Capsicum Annuum L.) Under Mixed Salt Stress

Superoxide Dismutase Catalyzed Size-Adjustable Selenium Nanoparticles in Saccharomyces boulardii.

Selenium nanoparticles (SeNPs) are important and safe food and feed additives that can be used for dietary supplementation. In this study, a mutagenic strain of Saccharomyces boulardii was employed to obtain biologically synthesized SeNPs (BioSeNPs) with the desired particle size by controlling the dosage and duration of sodium selenite addition, and the average particle size achieved was 55.8 nm with protease A encapsulation. Transcriptomic analysis revealed that increased expression of superoxide dismutase 1 (SOD1) in the mutant strain effectively promoted the synthesis of BioSeNPs and the formation of smaller nanoparticles. Under sodium selenite stress, the mutant strain exhibited significantly increased expression of glutathione peroxidase 2 (GPx2), which was significantly greater in the mutant strain than in the wild type, facilitating the synthesis of glutathione selenol and providing abundant substrates for the production of BioSeNPs. Furthermore, based on the experimental results and transcriptomic analysis of relevant genes such as sod1, gpx2, the thioredoxin reductase 1 gene (trr1) and the thioredoxin reductase 2 gene (trr2), a yeast model for the size-controlled synthesis of BioSeNPs was constructed. This study provides an important theoretical and practical foundation for the green synthesis of controllable-sized BioSeNPs or other metal nanoparticles with potential applications in the fields of food, feed, and biomedicine.

Synthesis, Characterisation, and in Vitro Biocompatibility Studies of Selenium Nanoparticles Synthesized using Hybanthus Enneaspermus Plant Extract for Potential Biomedical Applications

Hybanthus enneaspermus (HE) is a traditional medicinal plant used for treating various disease conditions. Selenium nanoparticles (SeNPs) possess various properties such as anticancer, antioxidant, etc. The objective of the present study is to conduct green synthesis of selenium nanoparticles using Hybanthus enneaspermus(HE) and evaluate their biocompatibility. Leaves of HE are utilized for synthesizing SeNPs. Characterization studies of HE-SeNPs are carried out using UV spectrophotometry, FT-IR spectroscopy, and SEM. To check the biocompatibility, hemolytic assay, and Annexin V-PI assays are carried out. A change in color is observed after the addition of sodium selenite to the leaf extract. UV spectrophotometry gives a peak at 271 nm confirming the synthesis of SeNPs. FT-IR gives peaks at 3224, 1565, 1399, 1078, 784, and 717 cm-1 with a fingerprint of 3500 - 1000 cm-1. SEM analysis shows the spherical morphology of the SeNPs. HE-SeNPs at lower concentrations cause less hemolysis. However, HE-SeNPs are found to be less biocompatible, so further studies are needed to confirm their biocompatible nature. SeNPs synthesized from HE can be ideal for biomedical applications but further studies are required to check its biocompatibility. Keywords: SeNPs, Hybanthus enneaspermus, green synthesis, biocompatibility.

Effects of Sodium Selenite on the Growth and Photosystem II Activity of Arthrospira platensis Gom.

Arthrospira platensis (A. platensis) is a species of cyanobacteria with high economic value; the species is commercially well known as Spirulina platensis, and A. platensis was used in this paper. Its high adaptability, high photosynthetic efficiency, and fast growth rate make it one of the few cyanobacteria that can be cultivated on a large scale. Therefore, using the selenium enrichment property of A. platensis to cultivate selenium-enriched A. platensis will not only enhance the physiological efficacy of A. platensis but also increase its economic value significantly. In this study, we investigated the effects of sodium selenite on the growth and photosynthetic performance of A. platensis selenium by setting different amounts and methods of sodium selenite addition, and we explored the optimal culture conditions of the best dosage and method of sodium selenite addition. The results showed that the experimental group treated with sodium selenite at 700 μmol/L had the fastest growth, and the contents of soluble protein, phycocyanin C, and chlorophyll a increased by approximately 67.9%, 1.44 times, and 38.8% compared to the control group, respectively. Superoxide dismutase (SOD) and catalase (CAT) activity increased by 1.88-fold and 65%, respectively, and malondialdehyde (MDA) levels were reduced by 62% compared to the control group. The results of the OJIP assay showed that the J and I points were significantly higher at the batch addition and treatment concentration of 700 μmol/L, with the rate of QA being reduced and the proportion of the slowly reduced PQ pool being increased. The values of the maximum light energy conversion efficiency (Fv/Fm) per unit of reaction center were higher in both sodium selenite treatment groups than in the control group, indicating that the light energy conversion efficiency of A. platensis was promoted under all concentration treatment conditions. The batch addition of sodium selenite at concentrations less than 700 μmol/L resulted in significantly higher ABS/RC values than the control, and they were far superior to the one-time addition method. The reason for this may have been that the batch addition of sodium selenite at low concentrations increased the light absorption capacity of the unit reaction center of PSII, resulting in a rise in captured light energy, a rise in the energy captured by the reaction center for electron transfer (ETo/RC), a decrease in the energy dissipated in the absorption of light energy by the reaction center (DIo/RC), and an increase in the photosynthetic performance index (PI abs).

Comparative Evaluation of Yeast Selenium and Sodium selenite Supplementation on Fertility, Hatchability and Antioxidant Status in Dual Purpose Laying Hens

Selenium (Se) is an essential trace element, involved in many biological processes in animals, such as antioxidant status, reproduction, immunity, reproduction, and thyroid hormone metabolism. Dual purpose Giriraja (180) hens of 30 weeks of age were randomly distributed into 4 treatment groups having 5 replicates of 10 (1 male + 9 females) birds each. Treatment groups were divided based on additional selenium supplementation to the basal diet. Accordingly, the basal diet was T1, with further addition of sodium selenite, sodium selenite + selenium-enriched yeast and selenium enriched yeast @ 0.5, 0.3 + 0.2, and 0.5 mg Se/kg basal diet to form diets for T2, T3, and T4, respectively. The experimental period was for 8 weeks @ 150g feed/day/bird. Fertility, hatchability and antioxidant status viz., levels of Glutathione peroxidase, Superoxide dismutase and Catalase were assessed. The addition of different sources of Se alone and their combination did not show any significant difference in fertility and hatchability parameters at the end of 4th and 8th weeks of the study. Similarly, no significant improvement was seen in the antioxidant status of the birds at the end of the experiment. In conclusion, the requirement of selenium, in layer (0.05-0.08mg/kg diet) can be met with the amount of Se present in the feed raw material. Hence additional selenium supplementation may not be required under normal environment and production conditions.

Bionanotechnology of Selenite Ions Recovery into Nanoselenium by Probiotic Strains of Lactobacteria and Tolerance of Lactobacteria to Sodium Selenite

Green synthesis of nanoparticles (NPs) using living cells is a promising and new tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs, but biological methods are preferred because of their environmentally friendly, clean, safe, cost-effective, simple, and efficient sources for high productivity and purity. Aim. To investigate the processes of bioreduction of selenite ions into nanoselenium by probiotic strains of lactobacilli Lactobacillus plantarum IMV B-7679 and L. casei IMV B-7280. Methods. Cultivation of lactobacilli L. plantarum IMV B-7679 and L. casei IMV B-7280 was carried out in vials (500 cm3) on a rotary shaker (220 rpm) at 30 °C for 2 days on the Man, Rogosa, and Sharpe (MRS) broth nutrient medium. Sodium selenite was additionally added to the environment in different concentrations from 1 to 30 ppm by Se. The number of viable bacterial cells in 1 mL of suspension was determined by the method of limiting dilutions in the case of sowing aliquots on a nutrient medium containing 0.2% agar-agar. Cultures of L. plantarum IMV B-7679 or L. casei IMV B-7280 were grown in the liquid MRS broth medium with low pH in the presence or absence of Na2SeO3. The concentration of sodium selenite ranged from 1 to 30 ppm by Se level. The number of microorganisms was determined by inoculation (0.1 mL of suspension) in dense media on cups with MRS agar medium, and the seeding dose was 107 cells/Petri dish. The tolerance of lactobacilli to the selenite ions was evaluated by the decrease in the number of CFU when sowing aliquots taken from culture samples grown in the presence or absence of selenite. The results of the experiments were presented in CFU and transferred to Log CFU/cm3. The characteristics of Nano-Se were studied using transmission electron microscopy (TEM). Results. It was found that after 48 h incubation in an MRS medium with the addition of sodium selenite from 1 to 30 ppm, the culture of L. plantarum IMV В-7679 was the most resistant. Thus, enrichment of the culture medium with 30 ppm of Se in the Na2SeO3 composition led to a decrease in the number of L. plantarum IMV B-7679 to 5.17 ± 0.09 Log CFU/cm3 against 4.41 ± 0.11 Log CFU/cm3 for L. casei IMV B-7280 in the control. The use of lower concentrations (1—3 ppm of Se in Na2SeO3) did not affect the change in morphology and cultural properties of L. plantarum IMV B-7679. The ability of L. casei IMV B-7280 and L. plantarum IMV B-7679 cultures to grow on MRSA nutrient medium in the presence of 3 ppm Se was shown. Higher tolerance to sodium selenite was found for L. plantarum IMV B-7679. Thus, increasing the concentration to 30 ppm of Se in the form of Na2SeO3 led to a decrease in the viability of only the culture of L. casei IMV B-7280. That is, the studied lactobacilli showed different ability to grow in the presence of selenite ions. The formation of round electron-dense granules sizing from 30 nm to 250 nm was observed using TEM. Both probiotic strains showed the ability to restore selenite ions with the accumulation of intracellular Nano-Se and the release of Nano-Se into the culture medium, which was accompanied by color shifts from yellowish to red-brown. The partial destruction of L. casei IMV B-7280 cells under the influence of oxyanions was revealed, which was accompanied by the release of culture-synthesized electron-dense Nano-Se particles. Conclusions. The optimal conditions for the growth of L. plantarum IMV B-7679 and L. casei IMV B-7280 in the presence of Na2SeO3 were established, and it was proved that lactobacilli have different abilities to grow in the presence of selenite ions. The obtained data indicate that the investigated probiotic strains showed the ability to restore selenite ions along with the accumulation of intracellular Nano-Se and the release of Nano-Se into the culture medium.

Sodium selenite addition promotes the proliferation of bovine mammary epithelial cells through the Akt-mTOR signalling pathway

Sodium selenite addition promotes the proliferation of bovine mammary epithelial cells through the Akt-mTOR signalling pathway

The use of Saccharomyces cerevisiae fermented coconut dregs with the addition of sodium selenite as a source of selenium in broiler diets

Fermentation has been practised in feed technology to bioconvert the inorganic minerals to organic compounds. A study was done to determine the effect of Saccharomyces cerevisiae fermented coconut dregs with the addition of selenium on growth performance, feed digestibility and the intestinal response of broiler chickens. The study used 112-day old unsexed broiler chicks for 6 weeks. The broilers were fed with 4 different experimental diets. The diets were basal diet (T1), basal diet plus 0.5% coconut dregs (T2), basal diet plus 0.5% of 5 days fermented coconut dregs (T3) and basal diet plus 0.5% of 7 days fermented coconut dregs (T4). The broilers were fed ad libitum and tap water was offered at all times. The broiler chicks were vaccinated against New Castle Diseases on the fourth day. Feeders and drinkers were placed inside the pen. The feeders, drinkers, pens and surroundings were cleaned whenever necessary. A completely randomized design was used in this study with four different treatment diets, four replicate cages of 7 birds each. The data found in this study was analyzed using an analysis of variance. A Tukey test was applied once a significant effect was detected in the analysis of variance. Results of the study indicate that body weight gain and dry matter digestibility increased when the birds were fed the diets T3 and T4. The relative gizzard weight of birds fed the T3 and T4 was lighter than the birds fed the T1 and T2. Feed intake, feed conversion ratio, carcass percentage and relative intestine weight were not affected by the experimental diets. In conclusion, feeding the birds with diets supplemented with Saccharomyces cerevisiae-fermented coconut dregs with additional selenium improved feed quality and broiler performance.

РОСТ И БИОЛОГИЧЕСКАЯ ПРДУКТИВНОСТЬ РАСТЕНИЙ ПОСЛЕ ОБРАБОТКИ МИКРОЭЛЕМЕНТНЫМ СОСТАВОМ

In laboratory conditions, the effect of sodium selenite and a mixture of sodium selenite and zeolite on the growth and biological productivity of peas was investigated. The soil was examined after harvesting. It was shown that the addition of both sodium selenite and the mixture of sodium selenite with zeolite to the soil with irrigation affects the development of the root system - the length of the main root in the first case increased by 16.5%, the height of the stems 30 days after planting was 29% more in comparison with the control variant, and in the second case, the length of the main root increased by 18.5%, the height of the length of the stems increased by 24% than that of the control. Processing of peas with microelements also caused a stimulation of the reproduction system: an increase in the number of inflorescences by 3 times and the number of beans in 3.4 times compared with the control. A 160-fold decrease in the selenium content and the introduction of zeolite did not cause a large difference in the obtained results (except for the number of beans - with the addition of zeolite, the number of beans increased by 8%). Biochemical indicators of pea biomass showed an increase in dry matter, in sugar content by 28.8%, but a decrease in crude protein by 17.7%, a decrease in carotene by 17.5%, nitrogen by 18% (when irrigated with sodium selenite). When treated pea with sodium selenite and zeolite, the sugar content increased by 85.5%, but it was observed a decrease in crude protein by 9.5%, in crude fat - by 16.5%, a decrease in carotene by 31.2%, a decrease in nitrogen by 9.4%. Analysis of the soil after harvesting showed in the option with the addition of sodium selenite a decrease in the amount of humus by 6.5%, mobile potassium by 18.5%, but an increase in mobile phosphorus by 6.6%, mobile calcium by 2.7%. In the option with the introduction of the mixture of sodium selenite and zeolite, no decrease in humus was observed, the content of mobile potassium decreased by 10.8%, the content of mobile phosphorus increased by 9.8%, mobile calcium by 3.5%. The acidity of the soil has not changed.

Accumulation of Phyto-mediated nano-CeO2 and selenium doped CeO2 on Macrotyloma uniflorum (horse gram) seed by nano-priming to enhance seedling vigor

Abstract Herein, we designed a facile nano-bio catalyst by equipping Phyto-mediated Cerium oxide (CeO2 NPs) and Selenium doped Cerium oxide (Se–CeO2 NPs) in a simplistic green way to boost germination and vigor of horse gram seeds with probable values on accumulation. High stable nano CeO2 was prepared with aqueous seed extract of Cassia angustifolia by an optimized amount of ammonium ceric sulphate solution, temperature, pH, and reaction duration. The properties and activities of CeO2 NPs were enhanced by the addition of sodium selenite as a source of selenium dopant. The powdered samples of CeO2 and Se–CeO2 were annealed and characterized using UV-DRS, FT-IR, XRD, DLS, and HRTEM with EDAX. The screened parameters define the particle size of CeO2 and Se–CeO2 which helps to protect plant cells without impairment. The Phyto-mediated CeO2 and Se–CeO2 nanoparticles were made to invigorate in Macrotyloma uniflorum (horse gram) seeds by nano-priming treatment. The determined germination rate, root phenotype, shoot phenotype, and vigor index by nano-priming were correlated with the hydropriming method without a negative impact. The cytotoxicity of the synthesized samples was also tested in the Vero cell line using MTT assay to prove its non-toxic nature. The effect of translocation and accumulation of CeO2 and Se–CeO2 was examined by viewing the cross-sectional images of root and stem in SEM with EDAX. The result investigates with conserve nanotechnological scheme on small scale application by nano-priming proves the existence of CeO2 and Se–CeO2 in the Macrotyloma uniflorum (horse gram) seed which primes the rapid yield in seed germination and seedlings vigor. The novel stable nano-bio catalyst Se–CeO2 with high protein plant source and sodium selenite as a dopant compound to enhance the yield of horse gram seed compared to CeO2 without raising cytotoxicity.

Development of Selenized Lactic Acid Bacteria and their Selenium Bioaccummulation Capacity

Selenized lactic acid bacteria (LAB) represent potentially safe and effective sources of selenium (Se), essential for human health, as lactic acid fermentation improves Se bioavailability and reduces its toxicity. LAB are generally recognized as safe (GRAS) and widely used in fermented dairy products. To facilitate selenized LAB implementation as a functional food, we developed and characterized new Se-enriched strains based on the food industry commercial strains Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922A as representatives of two LAB genera. We evaluated Se bioaccumulation capacity, Se biotransformation and growth ability in the presence of different sodium selenite concentrations (0–50 mg/L), and antioxidant properties (2, 2-diphenyl-1-picrylhydrazyl (DPPH) method) and cell surface hydrophobicity between Se-enriched and parental strains in vitro. Sodium selenite addition did not negatively influence growth of either strain; thus, 50 mg/L was chosen as the optimal concentration based on strain accumulation capacity. Selenization improved the antioxidant properties of both strains and significantly increased their cell surface hydrophobicity (p < 0.05). To our knowledge, this represents the first report of Se-enriched strain hydrophobicity as well as the first on Se speciation in families Enterococcaceae and Streptococcaceae. Moreover, both tested strains demonstrated good potential for Se-enrichment, providing a foundation for further in vitro and in vivo studies to confirm the suitability of these Se-enriched strains for industrial applications.

Effects of sodium selenite and coated sodium selenite addition on performance, ruminal fermentation, nutrient digestibility and hepatic gene expression related to lipid metabolism in dairy bulls

This study evaluated the effects of sodium selenite (SS) and coated SS (CSS) addition on performance, ruminal fermentation, nutrient digestibility and hepatic gene expression related to lipid metabolism in dairy bulls. Thirty-six Holstein bulls were randomly divided into three groups: without Se addition, addition of 0.3 mg/kg dry matter (DM) of Se from SS and addition of 0.3 mg/kg DM of Se from CSS, respectively. Dietary Se addition increased DM intake. Higher average daily gain and lower feed conversion ratio was observed for CSS addition. Ruminal pH and acetate to propionate ratio decreased, total volatile fatty acids concentration increased but ammonia-N concentration was unchanged with dietary Se addition. Apparent total-tract digestibility of DM, organic matter and crude protein was highest for CSS addition, followed by SS addition and then control. Bulls receiving Se addition had higher digestibility of ether extract, neutral detergent fibre and acid detergent fibre. Serum glucose and glutathione peroxidase and hepatic expression of peroxisome proliferator-activated receptor-α, sterol regulatory element-binding protein-1, carnitine palmitoyl transferase-1 and acetyl-CoA carboxylase-α was highest for CSS addition, followed by SS addition and then control. Bulls receiving CSS addition had higher serum total protein, albumin, triglyceride and total antioxigenic capacity. Addition of Se increased serum cholesterol, insulin and Se. Hepatic expression of stearoyl-CoA desaturase and 3‑hydroxy‑3-methylglutaryl-CoA reductase and Se content increased but content of total lipid and triglyceride was unchanged with Se addition. The data indicated that addition of Se increased performance and hepatic expression of gene related to lipid metabolism in bulls.

Efficiency of application of inorganic and nanopreparations of selenium and probiotics for growing young quails

Modern industrial poultry farming occupies a leading position in the production of dietary foods, for which it is appropriate to use biologically active substances and probiotics. The study compared the effectiveness of compound feed with the addition of sodium selenite, bio-nano-selenium and L. plantarum in terms of body weight, weight gain, feed consumption and safety of experimental quail. The quails of the Pharaoh meat breed were kept in the vivarium of Bila Tserkva National Agrarian University and by the method of analogues were divided into 4 groups - control and three experimental ones. The duration of the study was 35 days. The results of the study indicate that the use in the quail’s diet of probiotics (L. plantarum) and selenium preparations (sodium selenite and bio-nano-selenium) leads to a predominance of poultry experimental groups in live weight over control analogs. It was found that the growth of bird’s live weight during the experiment differed depending on the use of the Selenium medication or probiotic, and the most intense effect on live weight of quails was the use of bio-nanоselenium in the diet of poultry (11.8% at the end of the experiment). Changes in absolute and average daily body weight gains of experimental birds have been clarified. The use of sodium selenite in the diet of quail caused a tendency for an increase in gains compared with control analogs at the beginning of the study and a downward trend during the fifth week of the study. It was found that the use of probiotics and bio-nano-selenium caused an increase in quail growth, which was more pronounced and reliable when feeding bio-nano-selenium. The obtained results show that probiotic and selenium preparations reduce feed consumption by 1 kg of weight gain, body weight increase by 3.05–11.8% and by 3.3–6.6% increase the safety of the experimental livestock with the best indicators in the group, receiving bio-nano-selenium.

SELENIO TOTAL Y VIABILIDAD CELULAR EN LA OBTENCIÓN DE SELENIO-LEVADURA

Se obtiene selenio-levadura mediante el cultivo de la levadura Saccharomyces cerevisiae LALVIN Bourgovin RC 212 en el medio YEPD, con la adición de selenito de sodio (en concentraciones de 2 a 10 mg Se(IV)/L) durante la fase de crecimiento exponencial, después de 48 horas a 30°C y 200 rpm. La cuantificación de selenio total intracelular en la seleniolevadura es factible con el método espectrofotométrico almidón-yoduro a 590 nm y la adición de 8 mg Se(IV)/L proporciona mayor biomasa, una viabilidad celular superior al 90 %, coloración rosada y un contenido de selenio total intracelular de 738±30 mg/kg en base seca. Finalmente, la metodología utilizada para determinar el porcentaje de viabilidad celular y el método analítico propuesto para cuantificar el selenio total intracelular, son alternativas accesibles para el control del bioproceso

Assessing the ability of silage lactic acid bacteria to incorporate and transform inorganic selenium within laboratory scale silos

Selenium (Se) is a non-metallic trace element essential for normal cellular function, which has been linked with reduced risk of cancer, cardiovascular disease, cognitive decline and thyroid disease in humans. Se deficiency in livestock is associated with white muscle disease, retained placenta, ill-thrift and mastitis. Where Se status or bioavailability from the soil for plants is poor, livestock rely on supplemental Se in their diets predominantly as either sodium selenite (inorganic form) or selenised-yeast (organic form). As lactic acid bacteria (LAB) have been shown to incorporate Se as either organic or elemental (Nano-Se) there may be potential to use silage inoculant bacteria to improve the Se status of feed to provide the Se requirements of livestock. We screened twenty-seven LAB in MRS broth in the presence of sodium selenite for growth and uptake of Se as organic (selenocysteine and selenomethionine), inorganic (selenite and selenate) or/and Nano-Se, with the aim to identify potential candidates for a mini-silo study. Sodium selenite addition into the growth medium of LAB reduced growth rates but also resulted in the conversion of the inorganic sodium selenite into predominately Nano-Se and small quantities of organic-Se. Based on a rank analysis of growth and ability to take up (total Se content) and convert inorganic Se (Nano and organic Se content), three LAB were selected for further investigation as silage inoculants: L. brevis DSMZ (A), L. plantarum LF1 (B), and L. plantarum SSL MC15 (C). Each LAB was used as an inoculant within a grass mini-silo trial, either cultured in the presence of sodium selenite before inoculation or sodium selenite added to the inoculum at inoculation versus controls with no Se. The addition of sodium selenite either into the growth media of LAB or applied at inoculation of grass silage did not interfere with the ability of the LAB to act as a silage inoculant with no difference in silage fermentation characteristic between LAB with no Se added. The addition of sodium selenite either to the LAB growth medium or at inoculation resulted in the conversion of sodium selenite into Nano-Se and organic-Se (Nano-Se, ca. 103 higher than organic), as previously shown in the screening trial. There was no difference between the three LAB for incorporation of Se or in silage quality, indicating the potential to develop silage inoculants to increase the bioavailable form of Se (elemental and organic) to livestock through conversion of inorganic forms during ensiling.

Regulation of biosynthesis of lipids in Chlorella vulgaris by compounds of zinc, chromium and selenium

We studied molecular and metabolic mechanisms of regulated lipid biosynthesis in Chlorella vulgaris aquaculture. after addition of sodium selenite (10 mg/dm3) when added separately and in combination with Zn2+ (5 mg/dm3) and Cr3+ (5 mg/dm3) during 7 days of their action in order to obtain biotechnologically useful lipid products, enriched with microelements. Experiments were carried out in accordance with generally accepted hydrological and biochemical methods. It was established that micronutrients that were added into the medium result in an increase in the total content of lipids in the range of 10%. The redeployment of lipid classes in chlorella cells occurs due to the action of sodium selenite in favour of phospholipids by reducing the proportion of diacylglycerols, while the amount of triacylglycerols and nonetherified fatty acids does not change. Combined action of sodium selenite and zinc ions leads to the significant increase of the relative content of diacylglycerols, and partial increase of nonetherified fatty acids, at the same time in the cells we can observe a slight decrease in the proportion of triacylglycerols and phospholipids. Inclusion of 14C-bicarbonate in carbohydrates, proteins and lipids of Ch. vulgaris is significantly different both from the control group and from the group to which we added the investigated factors. However, the predominance of inclusion in lipids is 2–3 times higher than its inclusion into carbohydrates and 9–12 times higher in proteins. The increase of labeled bicarbonate inclusion intensity into carbohydrates occurs only in the case of joint action of sodium selenite and zinc ions, in proteins and lipids – in all cases of trace elemental activity. It was revealed that the general tendency is the reduction of the inclusion of bicarbonate in Ch. vulgaris triacylglycerols and its increase in phospholipids and nonetherified fatty acids, except for chromium ions, that modified the inclusion of the label into diacylglycerols, which may be due to the specific toxicity of the metal ions. The activation of lipogenesis after addition of selenium, zinc and chromium compounds was confirmed by an increase in the inclusion intensity of 14C-oleate in various classes of lipids that are present in chlorella and increased activity of glycerol-3-phosphatacyltransferase. Direction and regulation of lipid metabolism in Ch. vulgaris in the direction of increasing the amount and accumulation of lipids and their separate classes using sodium selenite in combination with Zn2+ and Cr3+ with the purpose of forming selenium-metal-lipid complexes can be used to obtain biologically active lipidous preparations enriched with essential microelements.

СЕЛЕНИТ НАТРИЯ КАК ИНТЕНСИФИКАТОР СОЛОДОРАЩЕНИЯ ДЛЯ ПИВОВАРЕННОГО ЯЧМЕНЯ

There is little scientific data on the use of sodium selenite, a mineral form of selenium, as an intensifier of malting. Therefore, this work is aimed at investigating the possibility of using sodium selenite in accelerating the malting process. To this end, barley of the Acha variety was soaked in an aqueous sodium selenite solution. The malt was obtained using the air-irrigation soaking method, with the barley being germinated in a laboratory-based malting plant. During the experiment, the degree of soaking and the temperature of the grain layer were varied. Under various conditions of barley soaking and germination, the maximum amylolytic activity of the malt was observed on the 4 th day of germination. The addition of sodium selenite led to the accumulation of amylases on the 3 rd day of germination. Based on the experimental data and mathematical modelling, the maximum amylolytic activity of the malt, when a sodium selenite aqueous solution with a concentration of 0.033 mg / l was used, was established. The amylolytic activity of the malt obtained by soaking barley grain with sodium selenite was shown to be 1.5 times higher than that in the reference sample. Thus, our studies have shown that sodium selenite can be used as an intensifier of the malting process.

Production of Selenium-Enriched Yeast (Kluyveromyces marxianus) Biomass in a whey-based Culture Medium

Fil: Gurdo, Nicolas. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - La Plata. Instituto de Investigaciones Biotecnologicas. Instituto de Investigaciones Biotecnologicas Dr. Raul Alfonsin (sede Chascomus). Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnologicas. Instituto de Investigaciones Biotecnologicas Dr. Raul Alfonsin (sede Chascomus); Argentina

Selenium enrichment, fruit quality and yield of winter jujube as affected by addition of sodium selenite

Winter jujube (Zizyphus jujuba Mill.) is a kind of high quality, fresh jujube fruit originated from China. Selenium (Se) affects the chemical composition and antioxidative properties in plants. At appropriate concentrations, Se acts as an antioxidant or activates mechanisms that can alleviate oxidative stress in the chloroplast, and enhances plant growth. Although the addition of Se is known to increase Se uptake in crops, it is unclear whether exogenous Se affects nutritional and functional components in winter jujube. Winter jujube trees were sprayed with selenium (as sodium selenite) at five concentrations (0, 25, 50, 100, or 200mg/L of Se) three times at the fruitlet stage between July and August. The Se content, ratio of organic Se to total Se in leaves and fruits, fruit quality, and yield were measured. At Se concentrations of 50mg/L or higher, total Se content increased rapidly whereas the ratio increased initially and decreased later. Different Se concentrations affected the quality of fruits differently: at 50mg/L, compared to their values in the unsprayed control trees, vitamin C content was greater by 20.94%; soluble sugars, 29.48%; total flavonoids, 43.48%; and the sugar: acid ratio, 41.81%. Along with the increase of Se addition, average fruit weight and yield of winter jujube presented a trend of increasing up to 50mgL−1 and decreasing thereafter. Thus, the foliar spray of sodium selenite at Se concentration of 50mg/L is recommended during the fruitlet stage of Zhanhua winter jujube.