Spatial distribution of bacterial community in EGSB reactor treating synthetic sulfate-containing wastewater at low organic loading rate

Abstract

Given that the consumption of organic substances entails costly biodesulfurization, the characteristics of the bacterial community in a reactor should be determined to increase the desulfurizing rate under low organic loading condition. In this study, the bacterial community distribution in the expanded granular sludge bed reactor used to treat sulfate-containing wastewater with low organic loading rate was determined by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and 16S rDNA clone library analyses. DGGE results showed that the predominant bacteria were stable and accounted for similar to 90 % sulfate removal efficiency. Differences in band positions and intensities indicated that the distribution and abundance of bacteria were affected by their positions in the reactor. Typical bands were identified in the bacterial community comprising Desulfovibrio, Desulfomicrobium, Thiomonas, Acinetobacter, Bacteroidetes, and Chloroflexi. Their functions in the reactor were also discussed. The possible links between the functional and microbial responses were also investigated based on the characteristic and spatial distribution of each bacterium in consortium.