We report here both the successful treatment of DMS in a biofilter and the dynamic changes that occur in the composition of the bacterial community of the biofilter during this process. Denaturing gradient gel electrophoresis of eubacterial 16S rDNA samples taken from packing material at different DMS removal stages revealed 11 distinct bands. Phylogenetic analysis showed that the sequences of these bands were closest to sequences of species of the Proteobacteria, Firmicutes, and Actinobacteria. The specific occurrence of these bacterial species varied mainly with DMS load, but it was also affected by the addition of glucose and by ambient temperature Based on the characteristics of the identified species, the system is conducive for such processes as sulfur oxidation, sulfate reduction, carbon oxidation, and fermentation The strains identified in this study are potential candidates for purifying waste gas effluents containing DMS gas (C) 2010 Elsevier Ltd All rights reserved.