富硒条件下蜜环菌菌株硒耐受性及胞外酶生物活性的研究

Biological activity and selenium tolerance of Armillaria mellea

摘要:

【目的】通过对蜜环菌（Armillaria mellea）的富硒驯化，研究各菌株硒耐受性、有机硒含量及生物活性的变化规律，从而获得生物活性更强的蜜环菌，并对富硒蜜环菌的生物学特征进行初步研究。【方法】以Na₂SeO₃为无机硒试剂对蜜环菌进行富硒驯化；采用氢化物原子荧光光谱法测定蜜环菌的硒含量，热水浴法测定蜜环菌的无机硒含量；根据形态学、生理生化特征筛选优良的蜜环菌菌株。【结果】蜜环菌对无机硒有较好的富集能力。菌株J-234对Na₂SeO₃的耐受浓度为100 mg/L，菌株M-H和A-10对Na₂SeO₃的耐受浓度为60 mg/L，菌株YN-2对Na₂SeO₃的耐受浓度为20 mg/L。硒含量测定的结果表明，菌株J-234硒含量为8.378 1 μg/g，菌株M-H硒含量为7.249 4 μg/g，菌株A-10硒含量为1.926 9 μg/g，菌株YN-2硒含量为3.606 1 μg/g。富硒菌株J-234生物活性最强，其木聚糖酶活力为92 522.46 U/L，淀粉酶酶活力为11 951.49 U/L，纤维素酶活力为8 439.47 U/L，漆酶活力为1.25 U/L，多肽含量为0.087 g/L。【结论】外源硒的添加使蜜环菌的生物活性增强，这为其他食药用真菌富硒驯化研究提供了参考。

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.