Solubilization of toxic metal minerals and metal tolerance of mycorrhizal fungi
Solubilization of toxic metal minerals and metal tolerance of mycorrhizal fungi
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DOI：
10.1016/j.soilbio.2004.10.013
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发表时间：
2005-05-01
影响因子：
9.7
通讯作者：
Gadd, GM
中科院分区：
文献类型：
--
作者：
Fomina, MA;Alexander, IJ;Gadd, GM
本文研究了杜鹃花科植物菌根真菌（ErM）和外生菌根真菌（EcM）对不同有毒金属（Cd、Cu、Pb、Zn）的溶解能力。将矿物质掺入固化的琼脂培养基中，并通过测量真菌生长后琼脂的澄清来评估溶解。放射状生长和生物量干重的测量提供了金属耐受性的指标：原子吸收分光光度法测量生物量中积累的金属。不同的矿物和真菌物种，以及来自不同程度的金属污染的网站菌株之间的金属耐受性和溶解能力有很大的差异。磷酸锌表现出最小的毒性，是最容易溶解的大多数测试的真菌菌株。有毒金属矿物的溶解与介质的pH值和真菌的生长和耐受性有关，似乎介质的酸化是大多数所研究的菌根真菌溶解矿物的主要机制。在磷酸铅、碳酸铅、硫化物和四氧化铅的存在下，观察到外生菌根菌株（> 60%的菌株）具有非常强的致死作用。与此相反，杜鹃花菌根菌株能够生长在铅矿物修正的媒体。一个显着比例的杜鹃花菌根文化（70-90%）溶解镉和铜磷酸盐和赤铜矿。没有一种杜鹃花类菌根真菌和外生菌根真菌能够在含铅矿物的琼脂中产生清晰的带。然而，许多真菌能够在其菌丝体中积累移动的Ph。从金属污染和未污染场地分离的种群之间的有毒金属矿物耐受性，矿物溶解和金属吸收的差异与有毒金属，这是在原来的污染环境中的主要污染物。在一般情况下，耐金属真菌生长和溶解有毒金属矿物质比非耐受菌株。(c)2004 Elsevier Ltd.保留所有权利。
This work investigates the ability of ericoid mycorrhizal (ErM) and ectomycorrhizal (EcM) fungi to solubilize different toxic metal (Cd, Cu, Ph, Zn)-containing minerals. Minerals were incorporated into solidified agar media and solubilization assessed by measuring clearing of the agar after fungal growth. Measurement of radial growth and biomass dry weight provided indications of metal tolerance: accumulated metal in the biomass was measured by atomic absorption spectrophotometry. Metal tolerance and solubilizing ability varied widely between different mineral and fungal species, and strains derived from sites of differing degrees of metal pollution. Zinc phosphate exhibited the least toxicity and was the easiest to solubilize by the majority of tested fungal isolates. Solubilization of toxic metal minerals was connected with both the pH of the medium and growth and tolerance of fungi and it seems that acidification of the medium was the main mechanism of mineral dissolution for most of the mycorrhizal fungi studied. A very strong lethal effect was observed for ectomycorrhizal isolates (> 60% of strains) in the presence of Pb phosphate, carbonate, sulphide and tetraoxide. In contrast, ericoid mycorrhizal isolates were able to grow on Pb-mineral-amended media. A significant proportion of ericoid mycorrhizal cultures (70-90%) solubilized Cd and Cu phosphates and cuprite. None of the ericoid mycorrhizal and ectomycorrhizal fungi were able to produce a clear zone in Pb mineral -containing agar. However, many fungi were able to accumulate mobilized Ph in their mycelia. Differences in toxic metal mineral tolerance, mineral solubilization and metal uptake between populations isolated from metal-polluted and uncontaminated sites were related to the toxic metal which was the main pollutant in the original contaminated environment. In general, metal-tolerant fungi grew and solubilized toxic metal minerals better than non-tolerant isolates. (c) 2004 Elsevier Ltd. All rights reserved.