Team:FAFU-CHINA

Overview

Synergism of Phosphate-solubilizing microoranisms-plant

interactions for bioremediation of metalliferous soils

    Continued worldwide industrialization has caused extensive environmental and human health problems. A wide variety of chemicals, e.g., heavy metals, pesticides, chlorinated solvents, etc., have been detected in different natural resources such as soil, water, and air. Among the pollutants, the heavy metals are of concern to human health due to their cytotoxicity, mutagenicity, and carcinogenicity.
    




Metalliferous soils

      Soil polluted by heavy metals represent an important environmental problem due to the toxic effects of metals, their accumulations throughout the food chain and the additional risk of groundwater contamination.
    




Phytoremediation

      Phytoextraction is based on the use of hyperaccumulator plants, which can tolerate and accumulate high concentration of metals. Ideal hyperaccumulators require the characteristics of deep rooted, rapid growth and a high amount of biomass. In fact, many hyperaccumulators are slow in growth, produce low bow biomass and cannot grow in metal-stress soil.




Phosphate-solubilizing bacteria

      Phosphorus is the second important key element after nitrogen as a mineral nutrient in terms of quantitative plant equirement. However, plants can use only a small amount of this P since 75–90% of added P is precipitated by metal–cation complexes, and rapidly becomes fixed in soils. In this regard, phosphate solubilizing microbes are considered as the most efficient and eco-friendly means for phytoremediation of metalliferous soils. Although, several bacterial strains have been identified as PSB their performance under in situ conditions is not reliable. Therefore,we genetically engineered our chassis B. megaterium as a new strategy to accelerate phytoremediation process.