Chromium bioremediation by Pseudomonas plecoglossicid and mesoporous silica nanoparticles from oil contaminated soils

The presence of cytotoxic and carcinogenic heavy metals such as Chromium in industrial wastewater is an important pollution for agricultural soils and natural water sources.  The aim of study was to evaluate chromium removal with a bacterium isolate form contaminated soil compared to mesoporous silica nanoparticles.

In this study, for isolate chromium decomposing bacteria, soil were sampled from different  of contaminated beach of Kiashahr. Preliminary identification of the isolated strains was done based on biochemical tests and then molecular identification of bacteria by 16SrRNA sequencing. Cr removal was evaluated with resistant strain and nanoparticles by Atomic absorption spectrometry (AAS), individually.   

Chromium-degrading bacteria were identified based on 16SrRNA analysis and 99% homology of Pseudomonas pelicoglucida. Removal of chromium by mesoporous silica nanoparticles at a concentration of 300 μg / ml was higher than the isolated strain of Pseudomonas pelicoglucida and showed a removal rate of up to 75%. However, by increasing the concentration of chromium by more than 600 micrograms per milliliter, the ability of bacteria to remove chromium from mesoporous silica nanoparticles showed better results by 80% to 72% chromium removal.

Results indicated Pseudomonas pelicoglucida and nanoparticles can be used to remove chromium from contaminated soils and waters. It is also recommended to use chromium-removing bacteria and nano-adsorbents to remove chromium at the same time to increase the efficiency of chromium removal.