Abstract
Recently, selenium (Se) enriched mushrooms have been exploited as dietary Se supplements, but our knowledge of the metabolic process during the Se enrichment process is far from complete. In this study, the uptake, tolerance and reduction of selenite in a widely cultivated mushroom, Flammulina velutipes, was investigated. The results showed that pH variation (from 5.5–7.5), metabolic inhibitor (0.1 mM 2,4-DNP) and P or S starvation led to 11–26% decreases in the selenite uptake rate of F. velutipes. This indicates that a minor portion of the selenite uptake was metabolism dependent, whereas a carrier-facilitated passive transport may be crucial. Growth inhibition of F. velutipes initiated at 0.1 mM selenite (11% decrease in the growth rate) and complete growth inhibition occurred at 3 mM selenite. A selenite concentration of 0.03–0.1 mM was recommended to maintain the balance between mycelium production and Se enrichment. F. velutipes was capable of reducing selenite to elemental Se [Se(0)] including Se(0) nanoparticles, possibly as a detoxification mechanism. This process depended on both selenite concentration and metabolism activity. Overall, the data obtained provided some basic information for the cultivation of the selenized F. velutipes, and highlighted the opportunity of using mushrooms for the production of Se(0) nanoparticles.
Highlights
Selenium (Se) is an essential trace element for humans and animals
Influences of pH, metabolic inhibitor and nutrient starvation on the selenite uptake The rate of selenite uptake was not significantly influenced by the medium pH (p > 0.05), yet its mean values decreased by 14% as the medium pH increased from 5.5–7.5 (Fig. 1A)
Growth responses of F. velutipes to 0–5 mM selenite The growth rate of F. velutipes in the solid cultivation began to be inhibited at 0.1 mM selenite (Fig. 2A; Table S3)
Summary
Selenium (Se) is an essential trace element for humans and animals. Supplementation of Se can be necessary because nutritional Se deficiency affects 500–1,000 million people worldwide, especially those from the Keshan disease area of China (Combs, 2001). The availability and biological activity of Se depend on its dose and chemical form (Turło et al, 2011). Se confers antioxidant capacities to a number of selenoproteins (Izquierdo, Casas & Herrero, 2010). Se is toxic because it generates oxidative stress and is involved in DNA damage (Izquierdo, Casas & Herrero, 2010; Manikovaet al., 2010).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
