Publications de Christof Holliger

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Biotrickling filter (BTF) technology was applied for the treatment of waste gas containing a mixture of chlorobenzene and 1,2-dichlorobenzene. An adapted microbial community was immobilised on a structured packing material. The strategy followed was to reach high removal efficiencies at initially low mass loading rates followed by an increase of the latter. This procedure was successful and resulted in a short start-up period of only 2 weeks. A 3-month operation under steady-state conditions showed good per

A new 9.9 kb catabolic transposon, Tn-Dha1, containing the gene responsible for tetrachloroethene (PCE) reductive dechlorination activity, was isolated from Desulfitobacterium hafniense strain TCE1. Two fully identical copies of the insertion sequence ISDh ...

The aerobic and anaerobic ammonium-oxidizing bacterial guilds were studied from two multilevel samplers in an ammonium-contaminated aquifer in the UK. By end point polymerase chain reaction (PCR), the presence of betaproteobacterial ammonium-oxidizing bact ...

Accurate control of groundwater pH is of critical importance for in situ biological treatment of chlorinated solvents. This study evaluated a novel approach for buffering subsurface pH that relies on the use of silicate minerals as a long-term source of al ...

Biomethane potential (BMP) tests are a valuable tool to design different parts of full-scale anaerobic digestion plants. Recent inter-laboratory studies have shown that the results of BMP tests can vary considerably and a comparison of BMP test norm protocols showed that the procedures are not rigorously defined, thus leaving room for interpretation. The goals of the present study were to develop a test protocol based on the existing ones but defining all steps precisely and to test the influence of the ori

Although polychlorinated biphenyls (PCBs) production was brought to a halt 30 years ago, recalcitrance to degradation makes them a major environmental pollutant at a global scale. Previous studies confirmed that organohalide-respiring bacteria (OHRB) were ...

The corrinoid cofactor is essential for organohalide respiration (OHR), a bacterial metabolism assisting towards environmental depollution. Two different strategies for obtaining corrinoids, are used by OHR bacteria, either de novo biosynthesis or salvaging from the environment. Although Dehalobacter restrictus depends strictly on OHR metabolism for growth, it cannot produce the essential corrinoid de novo. Genome analysis of D. restrictus revealed a complete set of corrinoid biosynthesis genes with the exc

Basic understanding of aerobic granular sludge (AGS) processes has mainly been obtained in laboratory-scale studies with simple synthetic wastewaters. Two approaches were applied here to make a step toward the comprehension of AGS systems treating real municipal wastewater. One approach consisted in increasing the complexity of the influent composition of an AGS sequencing batch reactor (SBR) fed with volatile fatty acids, the other in starting up four AGS SBRs with four different wastewaters. Nutrient remo

The genus Desulfitobacterium belong to the low-GC gram-positive phylogenic group and is a versatile obligate anaerobe capable of reducing very diverse terminal electron acceptors such as sulfite, nitrate, fumarate, thiosulfate, and a few polluting chlorinated compounds in a environmental-friendly energy metabolism called dehalorespiration. Analysis of available desulfitobacteria genomes revealed on one hand a high number of predicted proteins that are translocated in a folded conformation to or across the c

The transformation of conventional flocculent sludge to aerobic granular sludge (AGS) biologically removing carbon, nitrogen and phosphorus (COD, N, P) is still a main challenge in startup of AGS sequencing batch reactors (AGS-SBRs). On the one hand a rapi ...

Reductive dehalogenase (rdh) gene clusters are encoding proteins that enable organohalide respiring bacteria (OHRB) to couple the degradation of halogenated molecules to energy conservation. The transcription of rdh gene clusters is regulated by RdhK regulators belonging to the CRP/FNR-family. RdhK6 (previously called CprK1) in Desulfitobacterium hafniense was shown to activate the transcription of the chlorophenol rdh genes in presence of 3-hydroxy-4-chlorophenylacetate1,2. RdhK effector-binding domain bin

Two bubble column sequencing batch reactors fed with an artificial wastewater were operated at 20, 30 and 35°C. In a first stage, stable granules were obtained at 20°C whereas fluffy structures were observed at 30°C. Molecular analysis revealed high abunda ...

Degenerate and specific PCR primers were designed for the detection of chloroethene reductive dehalogenases (CE-RDase), the key enzymes of chloroethene dehalorespiration, based on sequence information of three CE-RDases and three chlorophenol (CP) RDases. For the design of the degenerate primers, seven conserved amino-acid blocks identified with different bioinformatic tools were used. For one block degenerate, primers containing a 5'-consensus clamp region specific for CE-RDases and a 3'-end degenerate cor

Kinetic information extracted from biochemical methane potential (BMP) tests is often reported but its value is unclear. Inter-laboratory reproducibility provides a useful indication of its value. Here we extracted estimates of the first-order rate constan ...

In the past decade, research on the transcription regulation of reductive dehalogenase (rdh) gene clusters (for a recent review, see [1]) revealed a new set of CRP/FNR-type transcription regulators, called RdhK [2,3]. Several members of this family have been characterized in Desulfitobacterium hafniense. CprK1 (also known as RdhK6 [3]) is responsible for the regulation of the chlorophenol rdh operon [4-5]. The binding of the CprK1 N-terminal domain to 3-chloro-4-hydroxyphenylacetate (effector) promotes C-te

Sphingomonas paucimobilis B90A contains two variants, LinA1 and LinA2, of a dehydrochlorinase that catalyzes the first and second steps in the metabolism of hexachlorocyclohexanes (R. Kumari, S. Subudhi, M. Suar, G. Dhingra, V. Raina, C. Dogra, S. Lal, J. ...

Process understanding of microbial communities containing organohalide-respiring bacteria (OHRB) is important for effective bioremediation of chlorinated ethenes. The impact of iron and sulfate reduction on cis-1,2-dichloroethene (cDCE) and vinyl chloride ...

Dehalorespiration is a process during which microbes derive energy by the reductive dehalogenation of chlorinated organic pollutants, by using them as electron acceptors. Characterization of the full dehalorespiration pathway in dehalogenating organisms is of great importance, as their physiological properties and substrate range will determine the extent of the bioremediation process and the conditions that should be used. Various Desulfitobacterium strains and Dehalobacter restrictus harbor the pceABCT ge

Desulfitobacterium hafniense strain TCE1 is capable of metabolically reducing tetra- and trichloroethenes by organohalide respiration. A previous study revealed that the pce gene cluster responsible for this process is located on an active composite transp ...

Complex I (NADH:ubiquinone oxidoreductase, NUO) and complex I-like enzymes have been detected in several organohalide-respiring bacteria at genomic and proteomic levels. The question of the involvement of these enzymes in organohalide respiration remains to be elucidated. Comparative physiology and proteomics were applied to study the role of the 11-subunit complex I-like enzyme in Desulfitobacterium hafniense strain DCB-2, a model organism able to conserve energy via organohalide respiration (OHR). It appe

Christof Holliger

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Steady-state and transient-state performance of a biotrickling filter treating chlorobenzene-containing waste gas

Isolation and characterization of Tn-Dha1, a transposon containing the tetrachloroethene reductive dehalogenase of Desulfitobacterium hafniense strain TCE1

Detection and Quantification of Bacteria Involved in Aerobic and Anaerobic Ammonium Oxidation in an Ammonium-Contaminated Aquifer

Evaluation of silicate minerals for pH control during bioremediation: Application to chlorinated solvents

Inoculum origin and adaptation had no influence on biomethane potential results with different substrates

Indirect Evidence Link PCB Dehalogenation with Geobacteraceae in Anaerobic Sediment-Free Microcosms

Salvage of the essential corrinoid cofactor in Dehalobacter restrictus

Influence of Wastewater Composition on Microbial Communities of Aerobic Granules and their Nutrient Removal Performances

THE TWIN-ARGININE TRANSLOCATION PATHWAY IN THE OBLIGATE ANAEROBE DESULFITOBACTERIUM

Optimization of operation conditions for the startup of aerobic granular sludge reactors biologically removing carbon, nitrogen, and phosphorous

Explore RdhK based regulatory network of organohalide respiration using a hybrid proteins strategy

Performance and microbial community composition dynamics of aerobic granular sludge from sequencing batch bubble column reactors operated at 20, 30, and 35°

Development of degenerate and specific PCR primers for the detection and isolation of known and putative chloroethene reductive dehalogenase genes

Assessing the value of kinetic results from biochemical methane potential tests: Reproducibility from a large inter-laboratory study

Hybrid proteins for the screening of transcription regulators of reductive dehalogenase gene clusters

Enantioselective transformation of α-hexachlorocyclohexane by the dehydrochlorinases LinA1 and LinA2 from the soil bacterium Sphingomonas paucimobilis B90A

Impact of iron- and/or sulfate-reduction on a cis-1,2-dichloroethene and vinyl chloride respiring bacterial consortium: experiments and model-based interpretation

Purification & characterization of PceC protein involved in dehalorespiration by desulfitobacterium & dehalobacter

The Physiological Opportunism of Desulfitobacterium hafniense Strain TCE1 towards Organohalide Respiration with Tetrachloroethene

Complex I-like enzymes in organohalide-respiring bacteria