Enhance the phytoremediation efficiency of Echinochloa colona (L.) Link for Pb-contaminated soil by phosphorus solubilizing bacteria

Abstract

A promising solution for phytoremediation of metal-contaminated soils is to use plants in combination with phosphate-solubilizing bacteria (PSB). In this study, we subjected to isolate PSB from paddy soil and investigate their ability in improving the phytoremediation of lead (Pb2+) by a weed plant (Echinochloa colona (L.) Link) as well as in promoting the growth of E. colona under Pb stress condition. Total 06 PSB (labeled from TB01 to TB06) were isolated and the TB04 showed the strongest phosphate-solubilizing activity with the highest values of phosphorus solubilization index (PSI = 7.13) obtained from Ca3(PO4)2. Especially, the phosphorus solubilizing ability of the TB04 strain was not affected by the high Pb2+concentration. The TB04 strain was identified as Pseudomonas putida Trevisan, 1889 (accession number FJ976601.1). Furthermore, E. colona inoculated with TB04 strain significantly increased the phytoremediation efficiency of Pb from Pb-contaminated soil and the growth was enhanced clearly. These results suggest that the TB04 strain could potentially use as an inoculant in combination with E. colona to construct novel constructed wetlands for phytoremediation of metal-contaminated soil.

Keywords

• lead immobilization
• Pseudomonas putida
• soil fertility
• phytoremediation
• metal-contaminated soil