微生物镉解毒机制及微生物-植物互作修复研究进展

Research progress in microbial detoxification of cadmium and bioremediation based on microorganism-plant interaction

摘要:

镉(cadmium, Cd)是引起粮食减产的主要金属之一，具有高溶解性及高迁移性，易被植物吸收和积累。微生物长期在镉胁迫的条件下进化出一系列的镉解毒机制。微生物对镉的解毒包括抑制Cd(II)的进入、促进Cd(II)的外排，以及将进入胞内的Cd(II)进行“扣押”。微生物的Cd(II)钝化是通过细胞吸附和胞外沉淀将游离态的Cd(II)进行钝化，这类微生物具有较强的土壤镉污染治理潜力。本文主要介绍微生物的镉解毒机制、微生物-微生物互作、微生物-植物互作机制及其在镉污染生物修复中应用的最新研究进展。

Abstract:

Cadmium (Cd) is one of the major hazardous pollutants threatening grain production. Cd(II) with good dissolubility and high mobility tends to be absorbed and accumulated by plants. Microorganisms have evolved detoxification mechanisms under Cd(II) stress, which include the inhibition of Cd(II) uptake, activation of Cd(II) efflux, and sequestration of Cd(II) into cells. A variety of microorganisms have been reported to immobilize Cd(II) by biosorption and extracellular precipitation. These microorganisms exhibit great potential to bioremediate cadmium-contaminated soils. This review summarizes the molecular mechanisms of microbial detoxification of cadmium, microbial interaction, and microorganism-plant interaction, and then introduces the latest research progress in the bioremediation of cadmium contamination by microorganisms.