Academy of Scientific and Innovative Research, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India.
Academy of Scientific and Innovative Research, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India; Environment & Sustainability Department, CSIR-Institute of Minerals and Materials Technology, Bhubaneswar, 751013, India.
Chemosphere. 2021 Jul;274:129976. doi: 10.1016/j.chemosphere.2021.129976. Epub 2021 Feb 15.
The most adverse outcome of increasing industrialization is contamination of the ecosystem with heavy metals. Toxic heavy metals possess a deleterious effect on all forms of biota; however, they affect the microbial system directly. These heavy metals form complexes with the microbial system by forming covalent and ionic bonds and affecting them at the cellular level and biochemical and molecular levels, ultimately leading to mutation affecting the microbial population. Microbes, in turn, have developed efficient resistance mechanisms to cope with metal toxicity. This review focuses on the vital tolerance mechanisms employed by the fungus to resist the toxicity caused by heavy metals. The tolerance mechanisms have been basically categorized into biosorption, bioaccumulation, biotransformation, and efflux of metal ions. The mechanisms of tolerance to some toxic metals as copper, arsenic, zinc, cadmium, and nickel have been discussed. The article summarizes and provides a detailed illustration of the tolerance means with specific examples in each case. Exposure of metals to fungal cells leads to a response that may lead to the formation of metal nanoparticles to overcome the toxicity by immobilization in less toxic forms. Therefore, fungal-mediated green synthesis of metal nanoparticles, their mechanism of synthesis, and applications have also been discussed. An understanding of how fungus resists metal toxicity can provide insights into the development of adaption techniques and methodologies for detoxification and removal of metals from the environment.
工业化的最不利后果是重金属对生态系统的污染。有毒重金属对所有形式的生物群都有有害影响，但它们直接影响微生物系统。这些重金属通过形成共价和离子键与微生物系统形成配合物，并在细胞水平、生化和分子水平上影响它们，最终导致影响微生物种群的突变。微生物反过来也发展了有效的抵抗机制来应对金属毒性。本综述重点介绍了真菌抵抗重金属毒性所采用的重要耐受机制。耐受机制基本上分为生物吸附、生物积累、生物转化和金属离子的外排。讨论了真菌对铜、砷、锌、镉和镍等一些有毒金属的耐受机制。本文总结并详细说明了每种情况下的耐受方法及其具体例子。金属暴露于真菌细胞会引发一种反应，可能导致形成金属纳米颗粒，通过固定在毒性较小的形式来克服毒性。因此，还讨论了真菌介导的金属纳米颗粒的绿色合成、其合成机制以及应用。了解真菌如何抵抗金属毒性可以为开发适应技术和方法提供启示，以实现从环境中解毒和去除金属。
