Copper biosorption and ions release by Stenotrophomonas maltophilia in the presence of benzo[a]pyrene

Abstract

To investigate metal biosorption in polluted environments where organic and inorganic pollutants coexisted, this study has focused on the removal of Cu(NO3)2 by Stenotrophomonas maltophilia in the presence of benzo[a]pyrene (BaP). Initial pH, biosorbent dosage, contact time and BaP concentration were the significant factors for Cu biosorption. The uptake capacities of 2 and 10mgL−1 Cu(II) by 0.25gL−1S. maltophilia were 7 and 26mgg−1 at 0.5h, respectively. Cu(II) biosorption included bioaccumulation, ions and macromolecules release, Ca2+ and Mg2+ exchange, functional groups attraction, and Cu(II) and NO3- bioreduction. During the biosorption process, S. maltophilia metabolically released K+, and metabolically independently exchanged Mg2+ and Ca2+ for Cu(II) bioaccumulation. When the initial concentration of Cu(II) was 2 or 10mgL−1, the coexisted 1mgL−1 BaP showed no significant influence on Cu(II) biosorption, ions release and cellular morphology.