铅、锰对黄伞菌丝形态及细胞活性的影响

Effects of lead and manganese stress on mycelium morphology and cell activity of Pholiota adiposa

摘要:

【目的】确定铅(Pb2+)、锰(Mn2+)对黄伞菌丝形态、结构及其菌丝活力的影响，并比较黄伞对Pb2+、Mn2+的适应性和耐受性。【方法】采用平板培养和液体培养方法，结合菌落形态和菌丝的电镜观察，测定菌落直径、菌丝鲜重，并以原子吸收分光光度计测定Pb2+、Mn2+含量。同时测定液体培养条件下菌丝的鲜重和胞外多糖产量以验证菌丝活力。【结果】不同Pb2+、Mn2+浓度下黄伞菌丝体形态变化明显，Pb2+、Mn2+的浓度≥500 mg/L可显著抑制黄伞菌丝的生长；高浓度Pb2+、Mn2+下(Pb2+≥700 mg/L、Mn2+≥2 000 mg/L)黄伞菌丝体锁状联合大量减少，且大小不一、分布不均，菌丝褶皱变形。黄伞在菌丝平板生长过程中，当Pb2+、Mn2+分别为100 mg/L时，黄伞菌丝生长速度最快。黄伞在液体培养过程中，当Mn2+浓度为300 mg/L、Pb2+浓度为50 mg/L时，菌丝鲜重以及产生的胞外多糖含量最大。【结论】Pb2+、Mn2+对黄伞的菌丝生长、菌丝活力及结构形态有较大的影响；黄伞对锰离子的适应性和耐性明显高于对铅离子的适应性和耐性。

Abstract:

[Objective] (1) To investigate the effect of Pb2+ and Mn2+ stress on the mycelium morphology, structure and vitality of Pholiota adiposa; (2) To compare the adaptability and resistance of P. adiposa to Pb2+ and Mn2+. [Methods] Mycelia in both plate medium and liquid medium were cultured. The morphological characteristics were studied via electron microscopy and the growth characteristics were recorded. Contents of Pb2+ and Mn2+ in mycelia were also determined by atomic absorption spectrometry. The production of exopolysaccharides by the mycelia in the liquid medium were measured with the phenol-sulfuric acid method as to validate the vitality of the mycelium. [Results] A significant reduction of clampconnection caused by Pb2+ and Mn2+ was observed, and meanwhile the clampconnection was found unevenly distributed with big differences in size under the stress. The mycelium appeared rugate and proteiform, suggesting the decrease of the mycelial vitality caused by Pb2+ and Mn2+ stresses. The colonies were larger than others when the concentration of Pb2+ or Mn2+ in the plate medium was 100 mg/L, while the growth was significantly inhibited when the concentration reached to or exceeded 500 mg/L. For the liquid culture, the fresh weight of mycelium and exopolysaccharide production reached to maximum when Pb2+ was 50 mg/L, or Mn2+ 300 mg/L. [Conclusion] High stress of Pb2+ and Mn2+ have a significant effect on the growth of the mycelium and the vitality of mycelium and morphology. The adaptability and resistance of P. adiposa to Mn2+ was higher than that to Pb2+.