Mechanism and application of bioremediation to heavy metal polluted soil using arbuscular mycorrhizal fungi

Abstract

Heavy鄄metal pollution in soil is a major threat to human health and the whole ecosystem, while bioremediation has become a promising option to recover the contaminated soils for its effective, non鄄intrusive and inexpensive. In particular, the application of symbiotic micro鄄organisms such as mycorrhizal fungi to enhance bioremediation efficiency has been paid more and more attention. Arbuscular mycorrhizal ( AM) fungi are one of the widely spread micro鄄organisms, which could form symbionts with most of the vascular plants in natural or artificial ecosystem. It has demonstrated that AM symbionts could increase the stressed ability of host plants in heavy metal polluted soil. Nowadays, using bioremediation methods to recovery heavy metal polluted soils with AM fungi has been one of the hotspots in environmental and ecological science. In order to review the physiological and molecular mechanism of heavy metals tolerance induced by AM fungi, four strategies were discussed in this paper: 1 ) the physical defense system formation, 2 ) the regulation to physiological metabolism of plants, 3) the production of biochemical antagonist material and 4) the regulation of gene expression. On the basis of this, this paper indicated that the possibility of using the system of AM鄄soil microbiology鄄host plant for remediation of heavy metals polluted soil in the future. For this purpose, to enhance the studies below would be necessary: 1 ) molecular mechanisms that AM fungi regulate heavy metal uptake and translocation; 2 ) phytoremediation of polymetal鄄 contaminated soils through selection of heavy metal tolerant AM fungi strains by genetic engineering; 3) the combination of other remediation techniques and AM鄄assisted bioremediation.

Research And Impact of Bioremediation on Soil Cadmium

“…This technology combines phytoremediation technology and microbial remediation technology to remediate heavy metal soil, that is, using the absorption of plants and the metabolism of microorganisms to remove heavy metal elements in the soil. Plant photosynthesis, root exudates, and fallen leaf residues can all provide nutrients for microorganisms [8], and microorganisms can activate heavy metals and help plants absorb beneficial elements from the soil. For example, tobacco rhizosphere + Pseudomonas fluorescens (more efficient than phytoremediation technology).…”