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Anaerobic benzene degradation under denitrifying conditions: Peptococcaceae as dominant benzene degraders and evidence for a syntrophic process
Author(s) -
van der Zaan Bas M.,
Saia Flávia Talarico,
Stams Alfons J. M.,
Plugge Caroline M.,
de Vos Willem M.,
Smidt Hauke,
Langenhoff Alette A. M.,
Gerritse Jan
Publication year - 2012
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/j.1462-2920.2012.02697.x
Subject(s) - benzene , electron acceptor , chemostat , denitrifying bacteria , nitrate , environmental chemistry , biology , chemistry , bacteria , denitrification , biochemistry , organic chemistry , ecology , nitrogen , genetics
Summary An anaerobic microbial community was enriched in a chemostat that was operated for more than 8 years with benzene and nitrate as electron acceptor. The coexistence of multiple species in the chemostat and the presence of a biofilm, led to the hypothesis that benzene‐degrading species coexist in a syntrophic interaction, and that benzene can be degraded in syntrophy by consortia with various electron acceptors in the same culture. The benzene‐degrading microorganisms were identified by DNA‐stable isotope probing with [U‐ 13 C]‐labelled benzene, and the effect of different electron donors and acceptors on benzene degradation was investigated. The degradation rate constant of benzene with nitrate (0.7 day −1 ) was higher than reported previously. In the absence of nitrate, the microbial community was able to use sulfate, chlorate or ferric iron as electron acceptor. Bacteria belonging to the Peptococcaceae were identified as dominant benzene consumers, but also those related to Rhodocyclaceae and Burkholderiaceae were found to be associated with the anaerobic benzene degradation process. The benzene degradation activity in the chemostat was associated with microbial growth in biofilms. This, together with the inhibiting effect of hydrogen and the ability to degrade benzene with different electron acceptors, suggests that benzene was degraded via a syntrophic process.