Benzene degradation in a denitrifying biofilm reactor: activity and microbial community composition.
Benzene is an aromatic compound and harmful for the environment. Biodegradation of benzene can reduce the toxicological risk after accidental or controlled release of this chemical in the environment. In this study, we further characterized an anaerobic continuous biofilm culture grown for more than 14 years on benzene with nitrate as electron acceptor. We determined steady state degradation rates, microbial community composition dynamics in the biofilm, and the initial anaerobic benzene degradation reactions. Benzene was degraded at a rate of 0.15 μmol/mg protein/day and a first-order rate constant of 3.04/day which was fourfold higher than rates reported previously. Bacteria belonging to the Peptococcaceae were found to play an important role in this anaerobic benzene-degrading biofilm culture, but also members of the Anaerolineaceae were predicted to be involved in benzene degradation or benzene metabolite degradation based on Illumina MiSeq analysis of 16S ribosomal RNA genes. Biomass retention in the reactor using a filtration finger resulted in reduction of benzene degradation capacity. Detection of the benzene carboxylase encoding gene, abcA, and benzoic acid in the culture vessel indicated that benzene degradation proceeds through an initial carboxylation step.
Deltares, Subsurface and Groundwater Systems, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands. Marcelle.vanderwaals@deltares.nl.|Wageningen University & Research, Laboratory of Microbiology, Stippeneng 4, 6708 WE, Wageningen, The Netherlands. Marcelle.vanderwaals@deltares.nl.
Marcelle J
MJ
van der Waals
Wageningen University & Research, Laboratory of Microbiology, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
Siavash
S
Atashgahi
VU University of Amsterdam, Department of Molecular Cell Physiology, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
Ulisses Nunes
UN
da Rocha
Deltares, Subsurface and Groundwater Systems, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands.
Bas M
BM
van der Zaan
Wageningen University & Research, Laboratory of Microbiology, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
Hauke
H
Smidt
Deltares, Subsurface and Groundwater Systems, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands.
Jan
J
Gerritse
D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D001554:Benzene / Q000378:metabolism* / Q000494:pharmacology; D019817:Benzoic Acid / Q000032:analysis; D001673:Biodegradation, Environmental; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D003470:Culture Media / Q000737:chemistry; D058440:Denitrification; D059013:Microbial Consortia / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D009566:Nitrates / Q000378:metabolism; D010459:Peptococcaceae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics
D003470:Culture Media; D009566:Nitrates; D012336:RNA, Ribosomal, 16S; D019817:Benzoic Acid; D001554:Benzene
Anaerobic benzene degradation; Biofilm reactor; Carboxylation; Denitrification; Peptococcaceae; Retentostat