Crognale Silvia, D'Annibale Alessandro, Pesciaroli Lorena, Stazi Silvia R, Petruccioli Maurizio
Department for Innovation in Biological Systems, Food and Forestry, University of Tuscia, Viterbo, Italy.
Front Microbiol. 2017 Nov 9;8:2202. doi: 10.3389/fmicb.2017.02202. eCollection 2017.
Although large quantities of heavy metal laden wastes are released in an uncontrolled manner by gold mining activities with ensuing contamination of the surrounding areas, there is scant information on the mycobiota of gold-mine sites. Thus, the present study was aimed to describe the fungal community structure in three differently As- and Hg-polluted soils collected from the Pestarena decommissioned site by using Illumina® metabarcoding. Fungal richness was found to increase as the contamination level increased while biodiversity was not related to the concentrations of inorganic toxicants. Within the phylum Zygomigota which, irrespective of the contamination level, was predominant in all the soils under study, the most abundant genera were and . The relative abundances of Basidiomycota, instead, tended to raise as the contamination increased; within this phylum the most abundant genera were and . The abundance of Ascomycota, ranging from about 8 to 21%, was not related to the contamination level. The relative abundances of those genera (i.e., , and ), the cultivable isolates of which exhibited significant As-resistance, were lower than the set threshold (0.5%). Mass balances obtained from As-exposure experiments with these isolates showed that the main mechanisms involved in counteracting the toxicant were accumulation and, above all, volatilization, the respective extents of which ranged from 0.6 to 5.9% and from 6.4 to 31.2% in dependence of the isolate.
尽管金矿开采活动以无控制的方式释放了大量含重金属的废物，导致周边地区受到污染，但关于金矿场地真菌群落的信息却很少。因此，本研究旨在通过使用Illumina®宏条形码技术描述从佩斯泰雷纳退役场地采集的三种不同程度砷和汞污染土壤中的真菌群落结构。研究发现，随着污染水平的增加，真菌丰富度增加，而生物多样性与无机毒物浓度无关。在接合菌门中，无论污染水平如何，在所研究的所有土壤中都是优势门类，其中最丰富的属是 和 。相反，担子菌门的相对丰度随着污染的增加而趋于上升；在这个门类中，最丰富的属是 和 。子囊菌门的丰度在8%至21%之间，与污染水平无关。那些属（即 、 和 ）的可培养分离株表现出显著的抗砷性，其相对丰度低于设定阈值（0.5%）。用这些分离株进行的砷暴露实验得到的质量平衡表明，对抗毒物的主要机制是积累，最重要的是挥发，其各自的程度根据分离株的不同在0.6%至5.9%和6.4%至31.2%之间。
