Molecular characterization of bacterial communities mineralizing benzene under sulfate-reducing conditions

• Published in: FEMS microbiology ecology Vol. 66; no. 1; pp. 143 - 157
• Main Authors: Kleinsteuber, Sabine, Schleinitz, Kathleen M, Breitfeld, Jana, Harms, Hauke, Richnow, Hans H, Vogt, Carsten
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.10.2008; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Actinobacteria; anaerobic degradation; Animal, plant and microbial ecology; Aquifers; Bacteria - genetics; Bacteria - metabolism; Benzene; Benzene - metabolism; Benzoates - metabolism; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Communities; Consortia; Cultivation; Degradation; Desulfotomaculum subcluster Ih; Desulfovibrio; DNA fingerprinting; DNA, Bacterial - genetics; Ecology; Ecosystem; Fingerprinting; Fresh Water - microbiology; Functionals; Fundamental and applied biological sciences. Psychology; Gene polymorphism; Genes, Bacterial; Genes, rRNA; Granular materials; Groundwater; Hydrocarbons; Microbial activity; Microbial ecology; Microbiology; Microcosms; Microorganisms; natural attenuation; Phenol - metabolism; Phylogeny; Polymorphism; Polymorphism, Restriction Fragment Length; Restriction fragment length polymorphism; RNA, Ribosomal, 16S - genetics; rRNA 16S; Sand; Sand & gravel; Substrate Specificity; Substrates; Sulfate reduction; Sulfates; Sulfates - metabolism; Sulfides - metabolism; syntrophy; Toluene - metabolism; Various environments (extraatmospheric space, air, water); Water Pollutants, Chemical - metabolism; natural attenuation; benzene; syntrophy; anaerobic degradation; subcluster Ih; Desulfotomaculum; Bacillaceae; Sulfates; Characterization; Degradation; Bacillales; Anaerobe; Benzene; Bacteria; Attenuation; Desulfotomaculum subcluster Ih; Microbial community
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.2008.00536.x

The microbial communities of in situ reactor columns degrading benzene with sulfate as an electron acceptor were analyzed based on clone libraries and terminal restriction fragment length polymorphism fingerprinting of PCR-amplified 16S rRNA genes. The columns were filled with either lava granules or sand particles and percolated with groundwater from a benzene-contaminated aquifer. The predominant organisms colonizing the lava granules were related to Magnetobacterium sp., followed by a phylotype affiliated to the genera Cryptanaerobacter/Pelotomaculum and several Deltaproteobacteria. From the sand-filled columns, a stable benzene-degrading consortium was established in sand-filled laboratory microcosms under sulfate-reducing conditions. It was composed of Delta- and Epsilonproteobacteria, Clostridia, Chloroflexi, Actinobacteria and Bacteroidetes. The most prominent phylotype of the consortium was related to the genus Sulfurovum, followed by Desulfovibrio sp. and the Cryptanaerobacter/Pelotomaculum phylotype. The proportion of the latter was similar in both communities and significantly increased after repeated benzene-spiking. During cultivation on aromatic substrates other than benzene, the Cryptanaerobacter/Pelotomaculum phylotype was outcompeted by other community members. Hence, this organism appears to be specific for benzene as a growth substrate and might play a key role in benzene degradation in both communities. Based on the possible functions of the community members and thermodynamic calculations, a functional model for syntrophic benzene degradation under sulfate-reducing conditions is proposed.