Biosorption of 1,2,3,4-tetrachlorodibenzo- p-dioxin and polychlorinated dibenzofurans by Bacillus pumilus

Microbial adsorption of 1,2,3,4-tetrachlorodibenzo- p-dioxin (1,2,3,4-TCDD) and various polychlorinated dibenzofurans (PCDFs) was investigated in an effort to determine the significance of microorganisms as potential agents in transferring the molecules in the environment. The microorganisms used in this study were cultivated under low nutrient conditions for 2 months. The increase and decrease of 1,2,3,4-TCDD and PCDFs in the samples were measured by GC/MS. The peak of dibenzofuran (DBF), added as an internal standard, was compared with the peaks of 1,2,3,4-TCDD and PCDFs. The results showed that the dead biomass of microorganisms could remove these molecules from the medium more effectively than live cells. The subsequent studies suggested that the removal of the molecules be concerned with the unknown biocompound(s) of which secretion is pronounced at high temperature. UV–VIS spectrometry was used to monitor the change in the concentration of biocompound(s).