Scale-up of removal process using a remediating-bacterium isolated from marine coastal sediment

Abstract

Nowadays, a wide variety of pollutants are discharged to different water sources and become water contaminants. To overcome this problem, bioremediation has been studied as an alternative for their treatment due to its low cost, high efficiency and environmentally friendliness. However, it is necessary to search for microorganisms able to remediate pollutants of different nature. In this work, the isolation and identification of remediating-bacteria from polluted marine coastal sediment were carried out. The isolation assays were carried out using phenanthrene as the only carbon source. The identification of the strains was performed by PCR amplification of 16S rDNA. It was resolved in one band and the sequencing showed that this band was derived from Serratia plymuthica. The removal ability of this microorganism was assayed with phenanthrene, benzo[a]pyrene, different insecticides and Cr(VI). The isolated bacterium showed high removal ability of imidacloprid, methomyl, fenamiphos, and Cr(VI). After that, bioreactor scale-up (5 L) was studied with a mixture of these pollutants. Total removal degrees were obtained for organic compounds and around 96% of Cr(VI) removal was reached. Furthermore, the removal rate of the different pollutants fitted well to a logistic model. The present study states that the identified bacterium can play a vital role in bioremediation of an aquatic environment polluted with mixtures of contaminants.