Selenium

About: Selenium is a research topic. Over the lifetime, 21192 publications have been published within this topic receiving 429715 citations. The topic is also known as: Se & selen.

Selenium content and distribution of human, cow and goat milk

Abstract: Studies were undertaken to compare the content and distribution of selenium in human, cow and goat milk. Selenium content of cow milk was found to be lower than that of either human or goat milk. Regardless of source, less than 3% of total milk selenium was associated with the lipid fraction. Selenium within the 120,000 X g supernatant accounted for 72, 62 and 30% of the total in cow, human and goat milk, respectively. Glutathione peroxidase occurred in all milk samples with goat greater than human greater than cow. Percent of total peroxidase activity associated with glutathione peroxidase was 29, 27 and 65 for human, cow and goat milk, respectively. Approximately 20-28% of the selenium in milk was removed by dialysis (molecular exclusion of 6-8 kDa). After gel chromatography, 8-12 selenoprotein fractions were detected in undialyzed skim milk from each species. Most of the glutathione peroxidase activity was found in the fractions corresponding to 170 and 96 kDa in milk from all species examined. The diameric form of glutathione peroxidase also appeared in dialyzed and undialyzed milk. Distinct differences in the content and distribution of selenoproteins among these species in fresh and dialyzed milk are discussed.

Elemental, Nano-Sized (100-500 nm) Selenium Production by Probiotic Lactic Acid Bacteria

Abstract: Selenium is well known as an essential trace element since the 20th century, but it can be overdosed easily because of its toxicity. According to the present regulations [1] only the potentially most harmful, inorganic selenium salts can be added to any comestibles. Elemental selenium is considered as the least toxical of all selenium forms and in the same time supplementation with its nano-size particles has the same or better bioavailability compared to its salts. In our experiments we managed to produce nano-size (100-500nm) elemental selenium by using probiotic yogurt bacteria in a fermentation procedure. We developed the laboratory technology of product purification and recovery from bacteria.

Selenate reduction by bacteria from a selenium-rich environment

Abstract: Samples collected from Kesterson Reservoir were screened for bacterial presence and selenate reduction capability. Selenate concentrations of 100 mg/liter were not toxic to indigenous bacteria. Of the 44 samples collected, 20 possessed microbial populations capable of reducing selenate. Reduction was observed in 4% of the water samples, 92% of the sediment samples, and 100% of the soil samples. Microbial reduction of 100 mg of selenate per liter was complete within 1 week of incubation. Up to 75 mg of selenate per liter was reduced beyond selenite to an insoluble red precipitate. Data collected indicate that indigenous bacteria have a significant role in the biogeochemical cycling of selenium.