Anaerobic mineralization of 2,4,6-tribromophenol to CO2 by a synthetic microbial community comprising Clostridium, Dehalobacter, and Desulfatiglans

Anaerobic mineralization of 2,4,6-tribromophenol (2,4,6-TBP) was achieved by a synthetic anaerobe community comprising a highly enriched culture of Dehalobacter sp. phylotype FTH1 acting as a reductive debrominator; Clostridium sp. strain Ma13 acting as a hydrogen supplier via glucose fermentation; and a novel 4-chlorophenol-degrading anaerobe, Desulfatiglans parachlorophenolica strain DS. 2,4,6-TBP was debrominated to phenol by the combined action of Ma13 and FTH1, then mineralized into CO2 by sequential introduction of DS, confirmed using [ring-14C(U)] phenol. The optimum concentrations of glucose, SO42−, and inoculum densities were 0.5 or 2.5 mM, 1.0 or 2.5 mM, and the densities equivalent to 104 copies mL−1 of the 16S rRNA genes, respectively. This resulted in the complete mineralization of 23 μM 2,4,6-TBP within 35 days (0.58 μmol L−1 d−1). Thus, using a synthetic microbial community of isolates or highly enriched cultures would be an efficient, optimizable, low-cost strategy for anaerobic bioremediation of halogenated aromatics.