Isolation of vanadium-resistance endophytic bacterium PRE01 from Pteris vittata in stone coal smelting district and characterization for potential use in phytoremediation

- Pteris vittata was a better V accumulator and have higher V resistance.
- V-resistant endophyte PRE01 from P. vittata was isolated and identified.
- PRE01 had plant growth promoting traits and strong V, Cr and Cd resistance.
- PRE01 possessed ability of V(V) and Cr(VI) reduction and Cd absorption.
- PRE01 was valuable for phytoextraction of vanadium ores contaminated soils.

This study investigates the V-resistant endophytic bacteria isolated from V-accumulator Pteris vittata grown on stone coal smelting district. Among all the ten isolates, the strain PRE01 identified as Serratia marcescens ss marcescens by Biolog GEN III MicroPlate™ was screened out by ranking first in terms of heavy metal resistance and plant growth promoting traits. The S. marcescens PRE01 had strong V, Cr and Cd resistance especially for V up to 1500 mg/L. In addition, it exhibited ACC deaminase activity, siderophore production and high indoleacetic acid production (60.14 mg/L) and solubilizing P potential (336.41 mg/L). For heavy metal detoxification tests, PRE01 could specifically assimilate 97.6%, 21.7% and 6.6% of Cd(II), Cr(VI) and V(V) within 72 h incubation. Despite the poor absorption of the two anions, most V(V) and Cr(VI) were detoxified and reduced to lower valence states by the strain. Furthermore, the isolate had the potential to facilitate the metals uptake of their hosts by changing heavy metal speciation. Our research may open up further scope of utilizing the endophyte for enhancing phytoextraction of vanadium industry contaminated soils.

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