Interaction between methanogenic and sulfate-reducing microorganisms during dechlorination of a high concentration of tetrachloroethylene

The Journal of General and Applied Microbiology

Nathalie Cabirol¹  François Jacob¹  Paul Chambon²  Bruno Fouillet²  Joseph Perrier¹ 

[1] Laboratoire de Microbiologie appliquée et industrielle, Université Claude Bernard-Lyon I;Laboratoire de Toxicologie et d'Hygiène industrielle, Faculté de Pharmacie

关键词: dechlorination;    methanogenesis;    microbial interactions;    reductants;    sulfate reduction;    tetrachloroethylene;   

DOI  :  10.2323/jgam.44.297

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

A methanogenic and sulfate-reducing consortium, which was enriched on medium containing tetrachloroethylene (PCE), had the ability to dechlorinate high concentrations of PCE. Dehalogenation was due to the direct activity of methanogens. However, interactions between methanogenic and sulfate-reducing bacteria involved modification of the dechlorination process according to culture conditions. In the absence of sulfate, the relative percentage of electrons used in PCE dehalogenation increased after an addition of lactate in batch conditions. The sulfate reducers would produce further reductant from lactate catabolism. This reductant might be used by methanogenic bacteria in PCE dechlorination. A mutualistic interaction was observed in the absence of sulfate. However in the presence of sulfate, methanogenesis and dechlorination decreased because of interspecific competition, probably between the H2-oxydizing methanogenic and sulfate-reducing bacteria in batch conditions. In the semicontinuous fixed-bed reactor, the presence of sulfate did not affect dechlorination and methanogenesis. The sulfate-reducing bacteria may not be competitors of H2-consuming methanogens in the reactor because of the existence of microbial biofilm. The presence of the fixed film may be an advantage for bioremediation and industrial treatment of effluent charged in sulfate and PCE. This is the first report on the microbial ecology of a methanogenic and sulfate-reducing PCE-enrichment consortium.

【 授权许可】

Unknown