Soil pollution from heavy metals poses a serious risk for environment and public health. Phytoremediation is an eco-friendly and cheaper alternative compared to chemical-physical techniques. We carried out in vitro tests where three microorganisms Trichoderma harzianum, Saccharomyces cerevisiae and Wickerhamomyces anomalus were exposed to eight different heavy metals (one metal at a time) in order to evaluate resistance, growth and bioaccumulation capability for each metal (Ni, Cd, Cu, V, Zn, As, Pb, Hg). Taking into account the natural characteristics of T. harzianum, (resistance to environmental stress, resistance to pathogenic fungi, ability to establish symbiotic relationships with superior green plants) and the good bioaccumulation capacity for V, As, Cd, Hg, Pb shown after in vitro tests, it was chosen as a microorganism to be used in greenhouse tests. Controlled exposure tests were performed in greenhouse, where Arundo donax and mycorrhized Arundo donax with T. harzianum were exposed for 7 months at two different doses (L1 and L2) of a heavy metal mix, so as to assess whether the symbiotic association could improve the bioaccumulation capability of the superior green plant A. donax. Heavy metals were determined with ICP-MS. The average bioaccumulation percentage values of A. donax for L1 and L2 were, respectively: Ni (31%, 26%); Cd (35%, 50%); Cu (30%, 35%); As (19%, 27%); Pb (18%, 14%); Hg (42%, 45%); V (39%, 26%); Zn (23%, 9%). The average bioaccumulation percentage values of mycorrhized A. donax with T. harzianum for L1 and L2 were, respectively: Ni (27%, 38%); Cd (44%, 42%); Cu (36%, 29%); As (17%, 23%); Pb (37%, 54%); Hg (44%, 60%); V (16%, 20%); Zn (14%, 7%). A. donax showed the highest BAF (bioaccumulation factor) for Cd (0.50), Cu (0.35), As (0.27) and Hg (0.45) after exposure to L2; mycorrhized A. donax with T. harzianum showed the highest BAF for Ni (0.38), Cd (0.42), Pb (0.54) and Hg (0.60) after exposure to L2. A. donax showed the highest TF (translocation factor) values for Cd (0.28) and Hg (0.26) after exposition at L1 and L2 respectively; A. donax mycorrhized with T. harzianum showed the highest TF values for Cd (0.70), As (0.56), V (0.24), Pb (0.18) after exposition at L2, and Zn (0.30) after exposition at L1. Our study showed a good growth capability in contaminated soils and a good bioaccumulation capability of heavy metals, both for A. donax and mycorrhized A. donax with T. harzianum. Furthermore, for three metals (Ni, Pb and Hg) the bioaccumulation capability was improved by the symbiosis of T. harzianum with A. donax. So, these results proved the suitability both for A. donax and mycorrhized A. donax with T. harzianum for phytoremediation processes.

中文翻译：

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重金属污染土壤中Arundo donax（Giant Reed）的植物修复潜力。

重金属污染土壤对环境和公众健康构成严重威胁。与化学物理技术相比，植物修复是一种环保且便宜的替代方法。我们进行了体外测试，其中将三种微生物哈茨木霉，酿酒酵母和异常柳条菌暴露于八种不同的重金属（一次一种金属），以评估每种金属（镍，镉，铜的抵抗力，生长和生物蓄积能力） ，V，Zn，As，Pb，Hg）。考虑到哈茨木霉的自然特性（对环境胁迫的抵抗力，对病原真菌的抵抗力，与优良绿色植物建立共生关系的能力）以及在下图中显示出的对V，As，Cd，Hg，Pb的良好生物积累能力体外测试 它被选作温室试验中使用的微生物。在温室中进行了有控制的暴露测试，其中以两种不同剂量（L1和L2）的重金属混合物将Arundo donax和已菌根的Arundo donax与harzianum暴露7个月，以评估共生关系是否可以改善优良绿色植物A. donax的生物蓄积能力。用ICP-MS测定重金属。L1和L2的A. donax的平均生物富集百分比分别为：Ni（31％，26％）; 镉（35％，50％）; 铜（30％，35％）; 为（19％，27％）; 铅（18％，14％）; 汞（42％，45％）; V（39％，26％）; 锌（23％，9％）。L1和L2的菌根曲霉和哈茨木霉菌的平均生物积累百分比分别为：Ni（27％，38％）; 镉（44％，42％）; 铜（36％，29％）; 为（17％，23％）; 铅（37％，54％）; 汞（44％，60％）; V（16％，20％）; 锌（14％，7％）。A. donax暴露于L2后，其Cd（0.50），Cu（0.35），As（0.27）和Hg（0.45）的BAF（生物蓄积因子）最高。暴露于L2后，菌根的哈茨木霉菌显示出最高的BAF，分别为Ni（0.38），Cd（0.42），Pb（0.54）和Hg（0.60）。A. donax分别在L1和L2暴露后显示出Cd（0.28）和Hg（0.26）的最高TF（转运因子）值；用哈茨木霉菌菌根的A. donax显示出最高的TF值，Cd（0.70），As（0.56），V（0.24），Pb（0.18）在L2暴露后和Zn（0.30）在L2暴露后。我们的研究表明，在污染土壤中具有良好的生长能力，重金属具有良好的生物富集能力，无论是对于A. donax还是菌根的A. donax与哈茨木霉。此外，对于三种金属（镍，P.和Hg）的生物积累能力通过哈茨木霉与唐氏草的共生而得到改善。因此，这些结果证明了无论是对于A. donax还是菌根的A. donax与哈茨木霉（T. harzianum），都适用于植物修复过程。