Research Progress on Mechanism of Phosphate-Solubilizing Microorganisms Combined with Phosphorite Powder Enhancing Phytoremediation of Lead-Contaminated Soil
Research Progress on Mechanism of Phosphate-Solubilizing Microorganisms Combined with Phosphorite Powder Enhancing Phytoremediation of Lead-Contaminated Soil
Phytoremediation of contaminated soil by heavy metal lead(Pb)has become one of the im-portant approaches for ecological restoration in mining areas.The remediation mechanisms of phosphate-solubi-lizing microorganisms and phosphorite powder enhancing phytoremediation to heavy metals have become re-search hotspots in soil ecological restoration.This article reviewed the phosphate-solubilizing mechanism of phosphate-solubilizing microorganisms and the biochemical processes involved in solidifying Pb in soil,ana-lyzed the chemical processes of phosphorite powder application changing Pb forms in soil,and examined the biochemical processes involved in synergistic effects of phosphate-solubilizing microorganisms with phosphorite powder on promoting plant growth and improving plant tolerance to Pb.(1)Phosphate-solubilizing microorgan-isms precipitated Pb by biosorption and biotransformation with free phosphate ions(PO34-)in soil,so reduced Pb migration and alleviated heavy metal toxicity.(2)Phosphate-solubilizing microorganisms secreted organic acids,acid phosphatase,phytase and C-P lyases to convert phosphorite powder into soluble phosphate salts that could bind with Pb,so as to enhance the passivation of Pb.(3)Phosphorite powder changed the forms of Pb in soil through precipitation,adsorption complexation and ion exchange;at the same time,PO34-released from phosphorite powder absorbed by the plant could alter the form and distribution of Pb2+in plant cells;it was distributed as a precipitated form of phosphate in root surface cell walls or vacuoles to reduce accumulation of Pb2+in aboveground part of the plant.(4)The advantages of coexistence systems were summarized invol-ving phosphate-solubilizing microorganisms synergistically acting with phosphorite powder for remediating soil contaminated by Pb,and the further researches were prospected in the future,in order to provide references for remediation of Pb-contaminated soil in China.
关键词
铅污染/解磷微生物/磷矿粉/植物修复
Key words
Lead pollution/Phosphate-solubilizing microorganism/Phosphorite powder/Phytoremedi-ation
维普
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