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Kinetic and thermodynamic control of butyrate conversion in non-defined methanogenic communities

Junicke, H. (author), Van Loosdrecht, M.C.M. (author), Kleerebezem, R. (author)

Many anaerobic conversions proceed close to thermodynamic equilibrium and the microbial groups involved need to share their low energy budget to survive at the thermodynamic boundary of life. This study aimed to investigate the kinetic and thermodynamic control mechanisms of the electron transfer during syntrophic butyrate conversion in non...

journal article 2015

document

Anaerobic digestion without biogas?

Kleerebezem, R. (author), Joosse, B. (author), Rozendaal, R. (author), Van Loosdrecht, M.C.M. (author)

Anaerobic digestion for the production of methane containing biogas is the classic example of a resource recovery process that combines stabilization of particulate organic matter or wastewater treatment with the production of a valuable end-product. Attractive features of the process include the production of a single end-product from a...

journal article 2015

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Influence of silicate on enrichment of highly productive microalgae from a mixed culture

Mooij, P.R. (author), De Jongh, L.D. (author), Van Loosdrecht, M.C.M. (author), Kleerebezem, R. (author)

Microalgae have the potential to supply a biobased society with essential feedstocks like sugar and lipids. Besides being productive, strains used for this purpose should grow fast, be resistant to predators, and have good harvestability properties. Diatoms, a class of siliceous algae, have these and other preferred characteristics. In this...

journal article 2015

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Effect of sludge age on methanogenic and glycogen accumulating organisms in an aerobic granular sludge process fed with methanol and acetate

Pronk, M. (author), Abbas, B. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

The influence of sludge age on granular sludge formation and microbial population dynamics in a methanol- and acetate-fed aerobic granular sludge system operated at 35°C was investigated. During anaerobic feeding of the reactor, methanol was initially converted to methane by methylotrophic methanogens. These methanogens were able to withstand...

journal article 2015

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Storage compound production by phototrophic diatoms

Mooij, P.R. (author), Van Loosdrecht, M.C.M. (author), Kleerebezem, R. (author)

The invention is directed to a method for producing an enriched diatom culture, comprising subjecting a starting culture comprising one or more diatom species to selective pressure, thus giving a competitive advantage to storage compound producing species of diatoms, by subjecting said starting culture, under non-limiting bioavailable silicon...

patent 2015

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Lipid recovery from a vegetable oil emulsion using microbial enrichment cultures

Tamis, J. (author), Sorokin, D.Y. (author), Jiang, Y. (author), Van Loosdrecht, M.C.M. (author), Kleerebezem, R. (author)

Background Many waste streams have a relatively high vegetable oil content, which is a potential resource that should be recovered. Microbial storage compound production for the recovery of lipids from lipid-water emulsions with open (unsterilized) microbial cultures was investigated in a sequencing batch reactor using a diluted vegetable oil...

journal article 2015

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Effect and behaviour of different substrates in relation to the formation of aerobic granular sludge

Pronk, M. (author), Abbas, B. (author), Al-zuhairy, S.H.K. (author), Kraan, R. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

When aerobic granular sludge is applied for industrial wastewater treatment, different soluble substrates can be present. For stable granular sludge formation on volatile fatty acids (e.g. acetate), production of storage polymers under anaerobic feeding conditions has been shown to be important. This prevents direct aerobic growth on readily...

journal article 2015

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Absolute Quantification of Individual Biomass Concentrations in a Methanogenic Coculture

Junicke, H. (author), Abbas, B. (author), Oentoro, J. (author), Van Loosdrecht, M. (author), Kleerebezem, R. (author)

Identification of individual biomass concentrations is a crucial step towards an improved understanding of anaerobic digestion processes and mixed microbial conversions in general. The knowledge of individual biomass concentrations allows for the calculation of biomass specific conversion rates which form the basis of anaerobic digestion models....

journal article 2014

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Nitrogen Removal by a Nitritation-Anammox Bioreactor at Low Temperature

Hu, Z. (author), Lotti, T. (author), De Kreuk, B.M. (author), Kleerebezem, R. (author), Van Loosdrecht, M. (author), Kruit, J. (author), Jetten, M.S.M. (author), Kartala, B. (author)

Currently, nitritation-anammox (anaerobic ammonium oxidation) bioreactors are designed to treat wastewaters with high ammonium concentrations at mesophilic temperatures (25 to 40°C). The implementation of this technology at ambient temperatures for nitrogen removal from municipal wastewater following carbon removal may lead to more-sustainable...

journal article 2013

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Method for obtaining an open phototrophic culture with improved storage compound production capacity

Tamis, J. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

The invention is directed to a method for producing an open phototrophic culture with improved storage compound production capability. In accordance with the invention, a starting culture is submitted to selective pressure, thus giving a competitive advantage to storage compound producing species, by subjecting said starting culture to a cycle...

patent 2013

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Metabolic modeling of denitrification in Agrobacterium tumefaciens: A tool to study inhibiting and activating compounds for the denitrification pathway

Kampschreur, M.J. (author), Kleerebezem, R. (author), Picioreanu, C. (author), Bakken, L. (author), Bergaust, L. (author), De Vries, S. (author), Jetten, M.S.M. (author), Van Loosdrecht, M.C.M. (author)

A metabolic network model for facultative denitrification was developed based on experimental data obtained with Agrobacterium tumefaciens. The model includes kinetic regulation at the enzyme level and transcription regulation at the enzyme synthesis level. The objective of this work was to study the key factors regulating the metabolic response...

journal article 2012

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Metabolic modeling of denitrification in Agrobacterium tumefaciens: A tool to study inhibiting and activating compounds for the denitrification pathway

Kampschreur, M.J. (author), Kleerebezem, R. (author), Picioreanu, C. (author), Bakken, L. (author), Bergaust, L. (author), De Vries, S. (author), Jetten, M.S.M. (author), Van Loosdrecht, M.C.M. (author)

journal article 2012

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Unravelling the reasons for disproportion in the ratio of AOB and NOB in aerobic granular sludge

Winkler, M.K.H. (author), Bassin, J.P. (author), Kleerebezem, R. (author), Sorokin, D.Y. (author), Van Loosdrecht, M.C.M. (author)

In this study, we analysed the nitrifying microbial community (ammonium-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB)) within three different aerobic granular sludge treatment systems as well as within one flocculent sludge system. Granular samples were taken from one pilot plant run on municipal wastewater as well as from two...

journal article 2012

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Effect of Elevated Salt Concentrations on the Aerobic Granular Sludge Process: Linking Microbial Activity with Microbial Community Structure

Bassin, J.P. (author), Pronk, M. (author), Muyzer, G. (author), Kleerebezem, R. (author), Dezotti, M. (author), Van Loosdrecht, M.C.M. (author)

The long- and short-term effects of salt on biological nitrogen and phosphorus removal processes were studied in an aerobic granular sludge reactor. The microbial community structure was investigated by PCR-denaturing gradient gel electrophoresis (DGGE) on 16S rRNA and amoA genes. PCR products obtained from genomic DNA and from rRNA after...

journal article 2011

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Effect of different salt adaptation strategies on the microbial diversity, activity, and settling of nitrifying sludge in sequencing batch reactors

Bassin, J.P. (author), Kleerebezem, R. (author), Muyzer, G. (author), Rosado, A.S. (author), Van Loosdrecht, M.C.M. (author), Dezotti, M. (author)

The effect of salinity on the activity of nitrifying bacteria, floc characteristics, and microbial community structure accessed by fluorescent in situ hybridization and polymerase chain reaction–denaturing gradient gel electrophoresis techniques was investigated. Two sequencing batch reactors (SRB1 and SBR2) treating synthetic wastewater were...

journal article 2011

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Analysis of ammonia-oxidizing bacteria dominating in lab-scale bioreactors with high ammonium bicarbonate loading

Vejmelkova, D. (author), Sorokin, D.Y. (author), Abbas, B. (author), Kovaleva, O.L. (author), Kleerebezem, R. (author), Kampschreur, M.J. (author), Muyzer, G. (author), Van Loosdrecht, M.C.M. (author)

The ammonia-oxidizing bacterial community (AOB) was investigated in two types of laboratory-scale bioreactors performing partial oxidation of ammonia to nitrite or nitrate at high (80 mM) to extremely high (428 mM) concentrations of ammonium bicarbonate. At all conditions, the dominant AOB was affiliated to the Nitrosomonas europaea lineage as...

journal article 2011

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Microbial community engineering for biopolymer production from glycerol

Moralejo-Gárate, H. (author), Mar'atusalihat, E. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

In this work, the potential of using microbial community engineering for production of polyhydroxyalkanoates (PHA) from glycerol was explored. Crude glycerol is a by-product of the biofuel (biodiesel and bioethanol) industry and potentially a good substrate for bioplastic production. A PHA-producing microbial community was enriched based on...

journal article 2011

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Process for selecting polyhydroxyalkanoate (PHA) producing micro-organisms

Van Loosdrecht, M.C.M. (author), Kleerebezem, R. (author), Jian, Y. (author), Johnson, K. (author)

The invention relates to a process for selecting a polyhydroxyalkanoate (PHA) producing micro-organism from a natural source comprising a variety of micro-organisms, comprising steps of preparing a fermentation broth comprising the natural source and nutrients in water; creating and maintaining aerobic conditions in the fermentation broth;...

patent 2009

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Xylose anaerobic conversion by open-mixed cultures

Temudo, M.F. (author), Mato, T. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

Xylose is, after glucose, the dominant sugar in agricultural wastes. In anaerobic environments, carbohydrates are converted into volatile fatty acids and alcohols. These can be used as building blocks in biotechnological or chemical processes, e.g., to produce bioplastics. In this study, xylose fermentation by mixed microbial cultures was...

journal article 2008

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Diversity of microbial communities in open mixed culture fermentations: Impact of the pH and carbon source

Temudo, M.F. (author), Muyzer, G. (author), Kleerebezem, R. (author), Van Loosdrecht, M.C.M. (author)

Anaerobic fermentation by an open mixed culture was investigated at different pH values (4–8.5) and with three substrates (glucose, glycerol and xylose). The populations established in each condition were assessed by denaturing gradient gel electrophoresis analysis of the 16S ribosomal RNA gene fragments. The fermentation pattern and the...

journal article 2008