Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, 17 Chunhui Road, Yantai, 264003, China.
National Risk Management Research Laboratory, United States Environmental Protection Agency, 5995 Center Hill Avenue, Cincinnati, OH, 45224-1701, USA.
Environ Sci Pollut Res Int. 2018 Sep;25(25):24965-24974. doi: 10.1007/s11356-018-2563-4. Epub 2018 Jun 22.
In this paper, a highly copper-resistant fungal strain NT-1 was characterized by morphological, physiological, biochemical, and molecular biological techniques. Physiological response to Cu(II) stress, effects of environmental factors on Cu(II) biosorption, as well as mechanisms of Cu(II) biosorption by strain NT-1 were also investigated in this study. The results showed that NT-1 belonged to the genus Gibberella, which exhibited high tolerance to both acidic conditions and Cu(II) contamination in the environment. High concentrations of copper stress inhibited the growth of NT-1 to various degrees, leading to the decreases in mycelial biomass and colony diameter, as well as changes in morphology. Under optimal conditions (initial copper concentration: 200 mg L, temperature 28 °C, pH 5.0, and inoculum dose 10%), the maximum copper removal percentage from solution through culture of strain NT-1 within 5 days reached up to 45.5%. The biosorption of Cu(II) by NT-1 conformed to quasi-second-order kinetics and Langmuir isothermal adsorption model and was confirmed to be a monolayer adsorption process dominated by surface adsorption. The binding of NT-1 to Cu(II) was mainly achieved by forming polydentate complexes with carboxylate and amide group through covalent interactions and forming Cu-nitrogen-containing heterocyclic complexes via Cu(II)-π interaction. The results of this study provide a new fungal resource and key parameters influencing growth and copper removal capacity of the strain for developing an effective bioremediation strategy for copper-contaminated acidic orchard soils.
本研究采用形态学、生理学、生物化学和分子生物学技术，对一株具有高耐铜性的真菌菌株 NT-1 进行了研究。文中还探讨了该菌株对 Cu(II)胁迫的生理响应、环境因素对 Cu(II)生物吸附的影响以及 NT-1 菌株对 Cu(II)的生物吸附机制。结果表明，NT-1 属于镰刀菌属，该属对环境中酸性条件和 Cu(II)污染均具有较高的耐受性。高浓度的铜胁迫会在不同程度上抑制 NT-1 的生长，导致菌丝体生物量和菌落直径的减少以及形态的改变。在最佳条件下（初始铜浓度：200 mg/L，温度 28°C，pH 值 5.0，接种量 10%），通过 NT-1 菌株在 5 天内培养，从溶液中去除铜的最大百分比达到了 45.5%。NT-1 对 Cu(II)的吸附符合拟二级动力学和 Langmuir 等温吸附模型，证实是一种由表面吸附主导的单层吸附过程。NT-1 与 Cu(II)的结合主要是通过形成多齿配合物与羧基和酰胺基通过共价相互作用，以及通过 Cu(II)-π 相互作用形成 Cu-含氮杂环配合物来实现的。本研究结果为开发有效的铜污染酸性果园土壤生物修复策略提供了一种新的真菌资源和影响菌株生长和铜去除能力的关键参数。
