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Ribeiro Pinela, Sara (author), Larasati, Amanda (author), Meulepas, Roel J.W. (author), Gagliano, Maria Cristina (author), Kleerebezem, R. (author), Bruning, Harry (author), Rijnaarts, Huub H.M. (author)(Bio)fouling is the most common problem in membrane processes used in water production. It is also a reported unavoidable problem, with mitigation strategies being frequently ineffective in addressing this problem. An ultrapure water plant (UPW) in Emmen (The Netherlands), fed with secondary effluent, comprises the following subsequent...journal article 2024
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Allaart, M.T. (author), Korkontzelos, Charilaos (author), Sousa, Diana Z. (author), Kleerebezem, R. (author)Syngas fermentation has gained momentum over the last decades. The cost-efficient design of industrial-scale bioprocesses is highly dependent on quantitative microbial growth data. Kinetic and stoichiometric models for syngas-converting microbes exist, but accurate experimental validation of the derived parameters is lacking. Here, we...journal article 2024
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Allaart, M.T. (author), Diender, Martijn (author), Sousa, Diana Z. (author), Kleerebezem, R. (author)Carboxydotrophic metabolism is gaining interest due to its applications in gas fermentation technology, enabling the conversion of carbon monoxide to fuels and commodities. Acetogenic carboxydotrophs play a central role in current gas fermentation processes. In contrast to other energy-rich microbial substrates, CO is highly toxic, which...journal article 2023
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Pei, R. (author), Vicente-Venegas, Gerard (author), Tomaszewska-Porada, Agnieszka (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Polyhydroxyalkanoates (PHAs) can be produced with municipal waste activated sludge from biological wastewater treatment processes. Methods of selective fluorescent staining with confocal laser scanning microscopy (CLSM) were developed and optimized to evaluate the distribution of PHA storage activity in this mixed culture activated sludge...journal article 2023
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Allaart, M.T. (author), Fox, B.B. (author), Nettersheim, I.H.M.S. (author), Pabst, Martin (author), Sousa, Diana Z. (author), Kleerebezem, R. (author)Hexanoate is a valuable chemical that can be produced by microorganisms that convert short-chain- to medium-chain carboxylic acids through a process called chain elongation. These microorganisms usually produce mixtures of butyrate and hexanoate from ethanol and acetate, but direct conversion of ethanol to hexanoate is theoretically possible....journal article 2023
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Pei, R. (author), Tarek-Bahgat, N. (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Poly(3-hydroxybutyrate) (PHB) was accumulated in full-scale municipal waste activated sludge at pilot scale. After accumulation, the fate of the PHB-rich biomass was evaluated over two weeks as a function of initial pH (5.5, 7.0 and 10), and incubation temperature (25, 37 and 55 °C), with or without aeration. PHB became consumed under aerobic...journal article 2023
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Vermeer, C.M. (author), Bons, Larissa J. (author), Kleerebezem, R. (author)Abstract: Using microbial enrichment cultures for the production of waste-derived polyhydroxyalkanoates (PHAs) is a promising technology to recover secondary resources. Volatile fatty acids (VFAs) form the preferred substrate for PHA production. Isobutyrate is a VFA appearing in multiple waste valorization routes, such as anaerobic...journal article 2022
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Estevez Alonso, A. (author), Arias-Buendía, María (author), Pei, R. (author), van Veelen, H. Pieter J. (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Activated sludge from municipal wastewater treatment processes can be used directly for the production of biodegradable polyesters from the family of polyhydroxyalkanoates (PHAs). However, municipal activated sludge typically cannot accumulate PHAs to very high levels and often low yields of polymer produced on substrate are observed. In the...journal article 2022
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Estevez Alonso, A. (author), Altamira-Algarra, Beatriz (author), Arnau-Segarra, César (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)The developments of mixed culture polyhydroxyalkanoate production has been directed to maximize the biomass PHA content with limited attention to polymer quality. Direct comparison of PHA accumulation literature is challenging, and even regularly contradicting in reported results, due to underlying differences that are not well expressed. A...journal article 2022
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Vermeer, C.M. (author), Depaz, Lena (author), van den Berg, Emily (author), Koelmans, Tom (author), Kleerebezem, R. (author)Medium-chain-length polyhydroxyalkanoate (mcl-PHA) production by using microbial enrichments is a promising but largely unexplored approach to obtain elastomeric biomaterials from secondary resources. In this study, several enrichment strategies were tested to select a community with a high mcl-PHA storage capacity when feeding octanoate. On...journal article 2022
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Pei, R. (author), Vicente-Venegas, Gerard (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Polyhydroxyalkanoate accumulation experiments at pilot scale were performed with fullscale municipal waste activated sludge. Development of biomass PHA content was quantified by thermogravimetric analysis. Over 48 h the biomass reached up to 0.49 ± 0.03 gPHA/gVSS (n=4). Samples were processed in parallel to characterise the distribution of...journal article 2022
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Vermeer, C.M. (author), Nielsen, Maaike (author), Eckhardt, Vincent (author), Hortensius, Matthijs (author), Tamis, J. (author), Picken, S.J. (author), Meesters, G.M.H. (author), Kleerebezem, R. (author)The biotechnological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from organic waste streams by mixed microbial communities is well established at the pilot-level. However, there is limited research on the recovery of the biopolymer from the microbial biomass, while its impact on product quality and product costs...journal article 2022
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Pei, R. (author), Estevez Alonso, A. (author), Ortiz-Seco, Laura (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Municipal activated sludge can be used for polyhydroxyalkanoate (PHA) production, when supplied with volatile fatty acids. In this work, standardized PHA accumulation assays were performed with different activated sludge to determine (1) the maximum biomass PHA content, (2) the degree of enrichment (or volume-to-volume ratio of PHA...journal article 2022
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Tamis, J. (author), Joosse, B.M. (author), de Leeuw, K.D. (author), Kleerebezem, R. (author)In this study, we investigated the operational performance and product spectrum of glucose-fermenting anaerobic granular sludge reactor at pH 4. A selective environment for the growth of granules was implemented by the introduction of a 2 min settling phase, a hydraulic retention time of 6 h and a solid retention time of 12 ± 3 days. The...journal article 2021
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Stouten, G.R. (author), Hamers, Kelly (author), van Tatenhove-Pel, R.J. (author), van der Knaap, E.D. (author), Kleerebezem, R. (author)Microbial community engineering aims for enrichment of a specific microbial trait by imposing specific cultivation conditions. This work demonstrates that things may be more complicated than typically presumed and that microbial competition can be affected by seemingly insignificant variables, like in this case the type of acid used for pH...journal article 2021
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Vermeer, C.M. (author), Rossi, E. (author), Tamis, J. (author), Jonkers, H.M. (author), Kleerebezem, R. (author)Polyhydroxyalkanoate (PHA) production is a promising opportunity to recover organic carbon from waste streams. However, widespread application of waste-derived PHA as biodegradable plastic is restricted by expensive purification steps, high quality requirements, and a fierce competition with the conventional plastic market. To overcome these...journal article 2021
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Estevez Alonso, A. (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)Microbial community-based polyhydroxyalkanoate (PHA) production has been demonstrated repeatedly at pilot scale. Ammonium, normally present in waste streams, might be oxidized by nitrifying bacteria resulting in additional aeration energy demand. The use of low dissolved oxygen (DO) concentrations allowed to reduce nitrifying rates by up to...journal article 2021
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Allaart, M.T. (author), Stouten, G.R. (author), Sousa, Diana Z. (author), Kleerebezem, R. (author)Anaerobic microbial communities can produce carboxylic acids of medium chain length (e.g., caproate, caprylate) by elongating short chain fatty acids through reversed β-oxidation. Ethanol is a common electron donor for this process. The influence of environmental conditions on the stoichiometry and kinetics of ethanol-based chain elongation...journal article 2021
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Moscoviz, Roman (author), Kleerebezem, R. (author), Rombouts, J.L. (author)Bioethanol production is an established biotechnological process. Margins are low which prevent a larger scale production of bioethanol. As a large part of the production cost is due to the feedstock, the use of low value unsterile feedstocks fermented by microbial communities will enable a more cost-competitive bioethanol production. To...review 2021
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Kleerebezem, R. (author), Lücker, Sebastian (author)The cyclic nature of specific conversions in the nitrogen cycle imposes strict limitations to the conversions observed in nature and explains for example why anaerobic ammonium oxidation (anammox) bacteria can only use nitrite – and not nitrate – as electron acceptor in catabolism, and why nitrite is required as additional electron donor for...journal article 2021