Dissertation/Thesis Abstract

Bioaccumulation and Transformation of Nanoscale Elemental Selenium in Fungal Mycelia
by Uppala, Ranjitha, M.S., Southern Illinois University at Edwardsville, 2016, 70; 10240357
Abstract (Summary)

Selenium (Se) is essential for humans and animals. The development and uses of Se-biofortified food products recently becomes one of the important agricultural research topics. Edible mushrooms are rich in proteins and essential amino acids, and mineral micronutrients like Se. Because of their medicinal values, some mushrooms have been widely used historically, and will become an important dietary source of Se intake. The aim of this laboratory study was to determine the feasibility of producing Se-enriched mushroom mycelia through the tissue culture approach, and effects of different Se chemical forms, including element Se nanoparticles, on Se accumulation in mycelium tissues of different mushroom species. The results showed that significant amounts of Se were accumulated in mycelium tissues, and Se bioaccumulation varied significantly (p<0.05) among the mushroom species, including Reishi (Ganoderma lucidum), Shiitake (Lentinula edodes), Lion’s mane (Hericium erinaceus), Oyster Pearl ( Pleurotus ostreatus) and Oyster Blue (Pleurotus columbinus ). The highest Se concentration (315 ± 19.4 mg/kg) was observed in Oyster Blue mycelia when the growth substrate was treated with sodium selenate (Na2SeO4), while the Se concentration of 155.99 ± 30.47 mg/kg was measured in the SeNPs treatment of 10 mg/L. Concentrations of Se accumulated in mycelium tissues of Reishi and Oyster Blue increased with increasing the level of Se treatment in growth media, from 1, 2.5, 5, to 10 mg/L and in the form of selenate (Na2SeO4) or elemental Se nanoparticles (SeNPs). Appearance of a characteristic red color in the tissues of Oyster Blue mycelium was observed only when treated with 5 mg/L selenite in the culture medium, which may be due to the transformation of selenite to elemental SeNPs. This study also demonstrated that nanoscale elemental Se can be biotransformed and volatilized by fungal mycelia, but the volatilization rate from selenate was much greater than that of SeNPs. Oyster Blue volatilized significant amounts of Se as high as 6449 ng/flask/day when the substrate was treated with sodium selenate and 6.5 ng/flask/day with the substrate treated with SeNPs.

Indexing (document details)
Advisor: Zhi-Qing, Lin
Commitee: Fowler, Tom, Theodorakis, Christopher W.
School: Southern Illinois University at Edwardsville
Department: Environmental Sciences
School Location: United States -- Illinois
Source: MAI 56/03M(E), Masters Abstracts International
Subjects: Food Science, Nanotechnology, Environmental science
Publication Number: 10240357
ISBN: 978-1-369-50583-2
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