土壤中特异性微生物与重金属相互作用机制与应用研究进展

随着经济的发展,矿产资源的开采和利用程度越来越高,一方面发现有地表露头矿床的几率越来越小,另一方面其造成的重金属污染严重危害环境和人类健康。自然界中的微生物与扩散到环境中的重金属会产生相互作用,具有这种特异性的细菌既可应用于指示隐伏金属矿床,亦可应用于重金属污染生物修复。本文从特异性微生物与重金属相互作用微观机制、微生物找矿、重金属污染土壤的微生物修复三个方面,对其研究现状和进展进行了评述,重点对特异性微生物与重金属离子发生的吸附、累积与转化过程,微生物改变重金属元素分布、赋存状态和毒性作用机理,蜡样芽孢杆菌(Bacillus cereus)与金的作用机制及其在寻找隐伏金矿的应用潜力,特异性微生物通过代谢产物吸附去除土壤中重金属元素及其辅助植物修复重金属污染等方面进行了介绍和阐述。

Research Progress on the Application and Interaction Mechanism between Specific Microorganisms and Heavy Metals in Soil

Soil pollution with heavy metals is becoming one of the most severe environment and human health hazards. Phytoremediation, using plants for the restoration of pollutants in environment, is an environmentally friendly, sustainable technology with no secondary pollution. Phytoremediation assisted by heavy metal specific microorganism has been highly recommended for cleaning up metal polluted soils, since specific bacteria can alleviate metal toxicity in plant through their own metal resistance system. In this paper, the mechanisms of interaction between specific microorganisms (such as Glomus mosseae) and heavy metals (such as Pb, As, Cd) and their effects on plant uptake of heavy metal were reviewed. It was found that specific microorganism can reduce the toxicity and enhance the bioavailability by biosorption, bioaccumulation and biotransformation (oxidation/reduction or ligand complexation) of heavy metals, and their secretory products (such as organic acids, auxin) can improve plant growth under heavy metal stress and thus enhance phytoextraction efficiency. The future researches may focus on disclosing the molecular mechanism of metal hyperaccumulation of heavy metal specific microorganisms and performing its application in field work.