document

Selecting for a high lipid accumulating microalgae culture by dual growth limitation in a continuous bioreactor

Policastro, G. (author), Ebrahimi, S. (author), Weissbrodt, D.G. (author), Fabbricino, Massimiliano (author), van Loosdrecht, Mark C.M. (author)

A dual-growth-limited continuous operated bioreactor (chemostat) was used to enhance lipid accumulation in an enrichment culture of microalgae. The light intensity and nitrogen concentration where both limiting factors resulting in high lipid accumulation in the mixed culture. Both conditions of light and nitrogen excess and deficiency were...

journal article 2024

document

Microbiome, resistome and mobilome of chlorine-free drinking water treatment systems

Calderon Franco, D. (author), Corbera Rubio, F. (author), Cuesta Sanz, M. (author), Pieterse, Brent (author), de Ridder, David (author), van Loosdrecht, Mark C.M. (author), van Halem, D. (author), Laureni, M. (author), Weissbrodt, D.G. (author)

Drinking water treatment plants (DWTPs) are designed to remove physical, chemical, and biological contaminants. However, until recently, the role of DWTPs in minimizing the cycling of antibiotic resistance determinants has got limited attention. In particular, the risk of selecting antibiotic-resistant bacteria (ARB) is largely overlooked in...

journal article 2023

document

Catch me if you can: capturing microbial community transformation by extracellular DNA using Hi-C sequencing

Calderon Franco, D. (author), van Loosdrecht, Mark C.M. (author), Abeel, T.E.P.M.F. (author), Weissbrodt, D.G. (author)

The transformation of environmental microorganisms by extracellular DNA is an overlooked mechanism of horizontal gene transfer and evolution. It initiates the acquisition of exogenous genes and propagates antimicrobial resistance alongside vertical and conjugative transfers. We combined mixed-culture biotechnology and Hi-C sequencing to...

journal article 2023

document

Turnover of the extracellular polymeric matrix of granules performing biological phosphate removal

Tomas Martinez, S. (author), Zwolsman, Erwin J. (author), Merlier, Franck (author), Pabst, Martin (author), Lin, Y. (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

Polyphosphate accumulating organisms (PAOs) are responsible for enhanced biological phosphate removal (EBPR) from wastewater, where they grow embedded in a matrix of extracellular polymeric substances (EPS). EPSs comprise a mixture of biopolymers like polysaccharides or (glyco)proteins. Despite previous studies, little is known about the...

journal article 2023

document

Metagenomic profiling and transfer dynamics of antibiotic resistance determinants in a full-scale granular sludge wastewater treatment plant

Calderon Franco, D. (author), Sarelse, R.G. (author), Christou, S. (author), Pronk, M. (author), van Loosdrecht, Mark C.M. (author), Abeel, T.E.P.M.F. (author), Weissbrodt, D.G. (author)

In the One Health context, wastewater treatment plants (WWTPs) are central to safeguarding water resources. Nonetheless, many questions remain about their effectiveness in preventing antimicrobial resistance (AMR) dissemination. Most surveillance studies monitor the levels and removal of selected antibiotic resistance genes (ARGs) and mobile...

journal article 2022

document

Light intensity defines growth and photopigment content of a mixed culture of purple phototrophic bacteria

Cerruti, M. (author), Kim, J.H. (author), Pabst, Martin (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

Purple bacteria (PPB), anoxygenic photoorganoheterotrophic organisms with a hyper-versatile metabolism and high biomass yields over substrate, are promising candidates for the recovery of nutrient resources from wastewater. Infrared light is a pivotal parameter to control and design PPB-based resource recovery. However, the effects of light...

journal article 2022

document

Adaptation of anammox bacteria to low temperature via gradual acclimation and cold shocks: Distinctions in protein expression, membrane composition and activities

Kouba, V. (author), D, Vejmelkova (author), E, Zwolsman (author), K, Hurkova (author), K, Navratilova (author), M, Laureni (author), Pabst, Martin (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

Anammox bacteria enable efficient removal of nitrogen from sewage in processes involving partial nitritation and anammox (PN/A) or nitrification, partial denitrification, and anammox (N-PdN/A). In mild climates, anammox bacteria must be adapted to ≤15 °C, typically by gradual temperature decrease; however, this takes months or years. To...

journal article 2022

document

Effect of temperature on the compositions of ladderane lipids in globally surveyed anammox populations

Kouba, Vojtěch (author), Hůrková, Kamila (author), Navrátilová, Klára (author), Kok, Dana (author), Benáková, Andrea (author), Laureni, M. (author), van Niftrik, Laura (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

The adaptation of bacteria involved in anaerobic ammonium oxidation (anammox) to low temperatures will enable more efficient removal of nitrogen from sewage across seasons. At lower temperatures, bacteria typically tune the synthesis of their membrane lipids to promote membrane fluidity. However, such adaptation of anammox bacteria lipids,...

journal article 2022

document

MiDAS 4: A global catalogue of full-length 16S rRNA gene sequences and taxonomy for studies of bacterial communities in wastewater treatment plants

Seviour, R (author), Tooker, Nick (author), Vainio, Pirjo (author), Dueholm, Morten Kam Dahl (author), Nierychlo, Marta (author), Andersen, Kasper Skytte (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author), Rossetti, S (author)

Microbial communities are responsible for biological wastewater treatment, but our knowledge of their diversity and function is still poor. Here, we sequence more than 5 million high-quality, full-length 16S rRNA gene sequences from 740 wastewater treatment plants (WWTPs) across the world and use the sequences to construct the ‘MiDAS 4’...

journal article 2022

document

Enrichment and application of extracellular nonulosonic acids containing polymers of Accumulibacter

Tomas Martinez, S. (author), Chen, Le Min (author), Pabst, Martin (author), Weissbrodt, D.G. (author), van Loosdrecht, Mark C.M. (author), Lin, Y. (author)

Abstract: Pseudaminic and legionaminic acids are a subgroup of nonulosonic acids (NulOs) unique to bacterial species. There is a lack of advances in the study of these NulOs due to their complex synthesis and production. Recently, it was seen that “Candidatus Accumulibacter” can produce Pse or Leg analogues as part of its extracellular...

journal article 2022

document

Catabolism of sialic acids in an environmental microbial community

Tomas Martinez, S. (author), Chen, L.M. (author), Neu, Thomas R. (author), Weissbrodt, D.G. (author), van Loosdrecht, Mark C.M. (author), Lin, Y. (author)

Sialic acids are a family of nine-carbon negatively charged carbohydrates. In animals, they are abundant on mucosa surfaces as terminal carbohydrates of mucin glycoproteins. Some commensal and pathogenic bacteria are able to release, take up and catabolize sialic acids. Recently, sialic acids have been discovered to be widespread among most...

journal article 2022

document

On anammox activity at low temperature: Effect of ladderane composition and process conditions

Kouba, Vojtěch (author), Hůrková, Kamila (author), Navrátilová, Klára (author), Kok, Dana (author), Benáková, Andrea (author), Laureni, M. (author), Vodičková, Patricie (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

The application of partial nitritation-anammox (PN/A) under mainstream conditions can enable substantial cost savings at wastewater treatment plants (WWTPs), but how process conditions and cell physiology affect anammox performance at psychrophilic temperatures below 15 °C remains poorly understood. We tested 14 anammox communities, including...

journal article 2022

document

Upgrading residues from wastewater and drinking water treatment plants as low-cost adsorbents to remove extracellular DNA and microorganisms carrying antibiotic resistance genes from treated effluents

Calderon Franco, D. (author), Apoorva, Seeram (author), Medema, G.J. (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author)

Wastewater treatment is challenged by the continuous emergence of chemical and biological contaminants. Disinfection, advanced oxidation, and activated carbon technologies are accessible in high-income countries to suppress them. Low-cost, easily implementable, and scalable solutions are needed for sanitation across regions. We studied the...

journal article 2021

document

Temperature and Nutrient Limitations Decrease Transfer of Conjugative IncP-1 Plasmid pKJK5 to Wild Escherichia coli Strains

Pallares Vega, R. (author), Macedo, Gonçalo (author), Brouwer, Michael S.M. (author), Hernandez Leal, Lucia (author), van der Maas, Peter (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author), Heederik, Dick (author), Mevius, Dik (author), Schmitt, Heike (author)

Plasmid-mediated dissemination of antibiotic resistance among fecal Enterobacteriaceae in natural ecosystems may contribute to the persistence of antibiotic resistance genes in anthropogenically impacted environments. Plasmid transfer frequencies measured under laboratory conditions might lead to overestimation of plasmid transfer potential...

journal article 2021

document

Annual dynamics of antimicrobials and resistance determinants in flocculent and aerobic granular sludge treatment systems

Pallares Vega, R. (author), Hernandez Leal, Lucia (author), Fletcher, Benjamin N. (author), Vias-Torres, Eduardo (author), van Loosdrecht, Mark C.M. (author), Weissbrodt, D.G. (author), Schmitt, Heike (author)

The occurrence and removal patterns of 24 antimicrobial agents and antimicrobial resistant determinants namely 6 antibiotic resistance genes (ARGs) and 2 mobile genetic elements (MGEs), and the fecal indicator E. coli were investigated in three full-scale wastewater treatment plants. Their waterlines and biosolids lines (including secondary...

journal article 2021

document

Production of nonulosonic acids in the extracellular polymeric substances of “Candidatus Accumulibacter phosphatis”

Tomas Martinez, S. (author), Kleikamp, H.B.C. (author), Neu, Thomas R. (author), Pabst, Martin (author), Weissbrodt, D.G. (author), van Loosdrecht, Mark C.M. (author), Lin, Y. (author)

Nonulosonic acids (NulOs) are a family of acidic carbohydrates with a nine-carbon backbone, which include different related structures, such as sialic acids. They have mainly been studied for their relevance in animal cells and pathogenic bacteria. Recently, sialic acids have been discovered as an important compound in the extracellular...

journal article 2021

document

Free-floating extracellular DNA: systematic profiling of mobile genetic elements and antibiotic resistance from wastewater

Calderon Franco, D. (author), van Loosdrecht, Mark C.M. (author), Abeel, T.E.P.M.F. (author), Weissbrodt, D.G. (author)

The free-floating extracellular DNA (exDNA) fraction of microbial ecosystems harbors antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs). Natural transformation of these xenogenetic elements can generate microbial cells resistant to one or more antibiotics. Isolating and obtaining high yield exDNA is challenging due to its low...

journal article 2020

document

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

document

Anticipating Xenogenic Pollution at the Source: Impact of Sterilizations on DNA Release From Microbial Cultures

Calderon Franco, D. (author), Lin, Qingnan (author), van Loosdrecht, Mark C.M. (author), Abbas, B.A. (author), Weissbrodt, D.G. (author)

The dissemination of DNA and xenogenic elements across waterways is under scientific and public spotlight due to new gene-editing tools, such as do-it-yourself (DIY) CRISPR-Cas kits deployable at kitchen table. Over decades, prevention of spread of genetically modified organisms (GMOs), antimicrobial resistances (AMR), and pathogens from...

journal article 2020

document

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