Biological activity and selenium tolerance of Armillaria mellea

Abstract:

[Objective] We studied the selenium tolerance, organic selenium content, and biological characteristics of the domesticated Armillaria mellea strains, so as to screen out the strains with strong biological activity. [Methods] Na₂SeO₃ was used as the inorganic selenium reagent to domesticate A. mellea. The selenium content and inorganic selenium content of A. mellea was determined by hydride atomic fluorescence spectrometry and hot water bath extraction method, respectively. Excellent A. mellea strains were identified based on morphological, physiological, and biochemical characteristics. [Results] A. mellea showed a good ability to accumulate inorganic selenium. The tolerance thresholds of strains J-234, M-H, A-10, and YN-2 to Na₂SeO₃ were 100, 60, 60, 20 mg/L, respectively. The selenium content in strains J-234, M-H, A-10, and YN-2 was 8.378 1, 7.249 4, 1.926 9, 3.606 1 µg/g, respectively. Strain J-234 had the highest biological activity after domestication, with the xylanase activity of 92 522.46 U/L, amylase activity of 11 951.49 U/L, cellulase activity of 8 439.47 U/L, laccase activity of 1.25 U/L, and polypeptide content of 0.087 g/L.[Conclusion] The addition of exogenous selenium enhances the biological activity of A. mellea, and this finding provides reference for the selenium domestication of edible and medicinal fungi.

Key words:Armillaria mellea;selenium domestication;selenium content;extracellular enzyme activity;polypeptide content