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Visualization of Polyhydroxyalkanoate Accumulated in Waste Activated Sludge

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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Influence of environmental conditions on accumulated polyhydroxybutyrate in municipal activated sludge

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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Calcium enhances polyhydroxyalkanoate production and promotes selective growth of the polyhydroxyalkanoate-storing biomass in municipal activated sludge

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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Process conditions affect properties and outcomes of polyhydroxyalkanoate accumulation in municipal activated sludge

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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Quantification of polyhydroxyalkanoate accumulated in waste activated sludge

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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Exploring the Limits of Polyhydroxyalkanoate Production by Municipal Activated Sludge

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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Simultaneous nitrification and denitrification in microbial community-based polyhydroxyalkanoate production

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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Scaling-up microbial community-based polyhydroxyalkanoate production: status and challenges

Estevez Alonso, A. (author), Pei, R. (author), van Loosdrecht, Mark C.M. (author), Kleerebezem, R. (author), Werker, A. (author)

Conversion of organic waste and wastewater to polyhydroxyalkanoates (PHAs) offers a potential to recover valuable resources from organic waste. Microbial community-based PHA production systems have been successfully applied in the last decade at lab- and pilot-scales, with a total of 19 pilot installations reported in the scientific...

review 2021

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Selecting for lactic acid producing and utilising bacteria in anaerobic enrichment cultures

Rombouts, J.L. (author), Kranendonk, Elsemiek Madeleine Maria (author), Regueira, Alberte (author), Weissbrodt, D.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

Lactic acid-producing bacteria are important in many fermentations, such as the production of biobased plastics. Insight in the competitive advantage of lactic acid bacteria over other fermentative bacteria in a mixed culture enables ecology-based process design and can aid the development of sustainable and energy-efficient bioprocesses....

journal article 2020

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Stratification of nitrifier guilds in granular sludge in relation to nitritation

Soler Jofra, A. (author), Wang, R. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author), Pérez, Julio (author)

A lab-scale partial nitritation granular sludge air-lift reactor was operated in continuous mode treating low strength synthetic medium (influent ca. 50 mg-N-NH₄ ⁺/L). Granules were initially stratified with AOB in the external shell and NOB in the inner core at 20 °C. Once temperature was decreased progressively from 20...

journal article 2019

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Denitrification as an N₂O sink

Conthe Calvo, M. (author), Lycus, Pawel (author), Arntzen, Magnus (author), Ramos da Silva, Aline (author), Frostegård, Åsa (author), Bakken, Lars R. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

The strong greenhouse gas nitrous oxide (N₂O) can be emitted from wastewater treatment systems as a byproduct of ammonium oxidation and as the last intermediate in the stepwise reduction of nitrate to N₂ by denitrifying organisms. A potential strategy to reduce N₂O emissions would be to enhance the activity of...

journal article 2019

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Diversity and metabolism of xylose and glucose fermenting microbial communities in sequencing batch or continuous culturing

Rombouts, J.L. (author), Mos, G. (author), Weissbrodt, D.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

A mechanistic understanding of microbial community establishment and product formation in open fermentative systems can aid the development of bioprocesses utilising organic waste. Kinetically, a single rate-limiting substrate is expected to result in one dominant species. Four enrichment cultures were operated to ferment either xylose or...

journal article 2019

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The impact of mixtures of xylose and glucose on the microbial diversity and fermentative metabolism of sequencing-batch or continuous enrichment cultures

Rombouts, J.L. (author), Mos, Galvin (author), Weissbrodt, D.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

Efficient industrial fermentation of lignocellulosic waste containing a large part of glucose and xylose is desirable to implement a circular economy. Mixed culture biotechnologies can aid in realizing this goal. The effect of feeding equivalent substrates to a microbial community, such a xylose and glucose, is not well understood in terms of...

journal article 2019

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Life on N₂O: deciphering the ecophysiology of N₂O respiring bacterial communities in a continuous culture

Conthe Calvo, M. (author), Wittorf, Lea (author), Kuenen, J.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author), Hallin, Sara (author)

Reduction of the greenhouse gas N₂O to N₂ is a trait among denitrifying and non-denitrifying microorganisms having an N₂O reductase, encoded by nosZ. The nosZ phylogeny has two major clades, I and II, and physiological differences among organisms within the clades may affect N₂O emissions from...

journal article 2018

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O₂ versus N₂O respiration in a continuous microbial enrichment

Conthe Calvo, M. (author), Parchen, C.M. (author), Stouten, G.R. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

Despite its ecological importance, essential aspects of microbial N₂O reduction—such as the effect of O₂ availability on the N₂O sink capacity of a community—remain unclear. We studied N₂O vs. aerobic respiration in a chemostat culture to explore (i) the extent to which simultaneous respiration of N...

journal article 2018

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Towards mainstream anammox: lessons learned from pilot-scale research at WWTP Dokhaven

Hoekstra, M. (author), Geilvoet, Stefan P. (author), Hendrickx, Tim L.G. (author), van Erp Taalman Kip, Charlotte S. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

The aim of this research was to study the biological feasibility of the Partial Nitritation/Anammox (PN/A) technology to remove nitrogen from municipal mainstream wastewaters. During stable process operations at summer temperatures (23.2 ± 1.3°C), the total nitrogen removal rate was 0.223 ± 0.029 kg N (m³d)⁻¹ while at...

journal article 2018

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Growth yield and selection of nosZ clade II types in a continuous enrichment culture of N₂O respiring bacteria

Conthe Calvo, M. (author), Wittorf, Lea (author), Kuenen, J.G. (author), Kleerebezem, R. (author), Hallin, Sara (author), van Loosdrecht, Mark C.M. (author)

Nitrous oxide (N₂O) reducing microorganisms may be key in the mitigation of N₂O emissions from managed ecosystems. However, there is still no clear understanding of the physiological and bioenergetic implications of microorganisms possessing either of the two N₂O reductase genes (nosZ), clade I and the more...

journal article 2018

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Grow or store? Exploring metabolic decision making under feast/famine conditions using 13C tracer

Verhagen, K.J.A. (author), Gabriel Guedes da Silva, L. (author), van de Wijgaart, R. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author), Wahl, S.A. (author)

Natural habitats of microorganisms are dynamic environments with non-continuous supply of carbon and energy sources, in which intermediate storage of substrates can increase competitiveness. Plasticicumulans acidivorans are polyhydroxybutyrate (PHB) accumulating bacteria enriched from activated sludge using carbon feast-famine cycles as...

poster 2017

document

Fermentative Bacteria Influence the Competition between Denitrifiers and DNRA Bacteria

van den Berg, E.M. (author), Perdigão Elisiário, M. (author), Kuenen, J.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

Denitrification and dissimilatory reduction to ammonium (DNRA) are competing nitrate-reduction processes that entail important biogeochemical consequences for nitrogen retention/removal in natural and man-made ecosystems. The nature of the available carbon source and electron donor have been suggested to play an important role on the outcome of...

journal article 2017

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Role of nitrite in the competition between denitrification and DNRA in a chemostat enrichment culture

van den Berg, E.M. (author), Rombouts, J.L. (author), Kuenen, J.G. (author), Kleerebezem, R. (author), van Loosdrecht, Mark C.M. (author)

Denitrification and dissimilatory nitrate reduction to ammonium (DNRA) are two microbial processes that compete for oxidized nitrogen compounds in the environment. The objective of this work was to determine the role of nitrite versus nitrate as terminal electron acceptor on the competition between DNRA and denitrification. Initially, a mixed...

journal article 2017