Characterization of Enterobacter intermedius MH8b and its use for the enhancement of heavy metals uptake by Sinapis alba L.

The aim of this study was to test whether the multiple-tolerant bacterium Enterobacter intermedius MH8b isolated from metal-contaminated soil is able to promote plant growth and enhance Zn, Cd and Cu uptake by Sinapis alba L. under laboratory conditions. Additionally, the mechanisms of the plant growth promotion and the ecological consequences of bioaugmentation were examined. MH8b exhibited the ability to produce 1-amino-cyclopropane-1-carboxylic acid deaminase, indole 3-acetic acid and hydrocyanic acid and was also able to solubilize inorganic phosphate. Soil inoculation with MH8b significantly increased plant biomass as well as the accumulation of Zn (32%) and Cd (94%) in plant shoots. DGGE and PLFA analysis revealed that the introduced MH8b had only a short-term influence on the structure of indigenous microbial communities. The plant growth-promoting properties of MH8b and its ability to increase the metal uptake connected with its long-term survival and its short-term impact on autochthonous microflora make the strain a good candidate for the promotion of plant growth and phytoremediation efficiency.

► Enterobacter intermedius MH8b promote the growth of Sinapis alba.
► E. intermedius MH8b influenced metal accumulation by plants.
► Tested strain survived during 28-days experiment.
► DGGE and PLFA indicated short-term impact of MH8b on autochtonous microflora.
► MH8b is a good candidate for plant growth promotion and phytoextraction.