Willy Verstraete's research while affiliated with Ghent University and other places

Publications (409)

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The core responsibility of governments is the security of their citizens, and this means inter alia protecting their safety, nutrition and health. Microbiology and microbial biotechnology have key roles to play in improving supply security of essential resources. In this paper, we discuss the urgent need to fully and immediately exploit existing mi...
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The planet is experiencing all manner of environmental crises, and crises that have their origins in the environment, including global warming, pollution of the air, soil, marine systems and freshwater, loss of habitats and species extinctions, transmission of deadly animal infections to humans, the spread of antimicrobial resistance, to name just...
Article
Carbon and nitrogen present in residual water streams can be converted into microbial protein and used as animal feed in aquaculture. While microbial protein is thought to be more environmentally sustainable when compared to proteins made from fish residues or plants, nothing is known about how it performs in an absolute sustainability perspective,...
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Microbial treatment of biodegradable wastes not only ensures neutralization of harmful substances such as volatile organic compounds but also enables valorization and bio-circularity within the society. Single cell protein (SCP) is a value-added product that can be obtained from biodegradable waste materials such as food waste via microbial ferment...
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The transition to sustainable agriculture and horticulture is a societal challenge of global importance. Fertilization with a minimum impact on the environment can facilitate this. Organic fertilizers can play an important role, given their typical release pattern and production through resource recovery. Microbial fertilizers (MFs) constitute an e...
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Microbes and their activities have pervasive, remarkably profound and generally positive effects on the functioning, and thus health and well‐being, of human beings, the whole of the biological world, and indeed the entire surface of the planet and its atmosphere. Collectively, and to a significant extent in partnership with the sun, microbes are t...
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Our communication discusses the profound impact of bio-based economies – in particular microbial biotechnologies – on SDG 8: Promote sustained, inclusive and sustainable economic growth, full and productive employment and decent work for all. A bio-based economy provides significant potential for improving labour supply, education and investment, a...
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This paper reports the conclusions of the three panel discussions held during the WasteEng2016 Conference in Albi, France (http://www.wasteeng2016.org/). It explores the research and development trends aiming at the production of energy and added value materials from waste and/or biomass. Three approaches are investigated: thermochemical conversion...
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The signature and almost unique characteristic of microbial technology is the exceptional diversity of applications it can address, and the exceptional range of human activities and needs to which it is and can be applied. Precisely because sustainability goals have very diverse and complex components and requirements, microbial technology has the...
Article
Spent sulphite liquor (SSL) was used as carbon source for the production of succinic acid using immobilized cultures of Actinobacillus succinogenes and Basfia succiniciproducens on two different supports, delignified cellulosic material (DCM) and alginate beads. Fed-batch immobilized cultures with A. succinogenes in alginates resulted in higher sug...
Chapter
In this volume, two main aspects are addressed. First, there is the enzymatic machinery dealing with hydrocarbons, fats, and oils. There is great progress in this domain and plenty of novel routes are still possible to explore and to upgrade to bring better microbial derived toolboxes to market implementation. Secondly there is the vast array of mi...
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Microbial biotechnology is an exceptionally dynamic and exciting sector of the biomedical sciences that is unique in the breath and diversity of products and services it provides/will provide and to which it contributes, such as disease prevention and therapy, diagnostics, agriculture and horticulture, food provision and nutrition, energy productio...
Article
Ultrafiltration and nanofiltration of spent sulphite liquor (SSL) has been employed to evaluate the simultaneous production of lignosulphonates and bio-based succinic acid using the bacterial strains Actinobacillus succinogenes and Basfia succiniciproducens. Ultrafiltration with membranes of 10, 5 and 3 kDa molecular weight cut-off result in signif...
Article
Spent sulphite liquor (SSL) has been used for the production of lignosulphonates (LS), antioxidants and bio-based succinic acid. Solvent extraction of SSL with isopropanol led to the separation of approximately 80% of the total LS content, whereas the fermentations carried out using the pretreated SSL with isopropanol led to the production of aroun...
Article
There is an urgent need to secure global supplies in safe water and proteinaceous food in an eco-sustainable manner, as manifested from tensions in the nexus Nutrients–Energy–Water–Environment–Land. This paper is concept based and provides solutions based on resource recovery from municipal and industrial wastewater and from manure. A set of decisi...
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No abstract is available for this article.
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Anaerobic digestion (AD) has long been used to treat different types of organic wastes especially in the developed world. However, organic wastes are still more often considered as a waste instead of a resource in the developing world, which contributes to environmental pollution arising from their disposal. This study has been conducted at Bugolob...
Article
The increase in the world population, vulnerability of conventional crop production to climate change, and population shifts to megacities justify a re-examination of current methods of converting reactive nitrogen to dinitrogen gas in sewage and waste treatment plants. Indeed, by up-grading treatment plants to factories in which the incoming mater...
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npj Biofilms and Microbiomes, Published online: 25 March 2015; | doi:10.1038/npjbiofilms.2015.1
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In all industrialized countries, the manufacturing industry appears to be in difficulty: the costs of maintaining skilled workers to do complicated technical tasks are becoming a major hurdle. The fact that a majority of the young professionals will spend their whole lives just typing in front of a screen is worrying plenty of sociologists, particu...
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This article addresses biochar from a legal point of view. It analyses different policies and regulations from a European (Flemish) point of view and provides a first and general insight in what potential legal constraints the development of a biochar industry might face and what opportunities lie ahead. This is due to the fact that biochar is a re...
Article
Filamentous bacteria such as Microthrix parvicella can cause serious foaming and floating sludge problems in anaerobic digesters fed with sewage sludge. The sewage sludge and oil co-fermenting laboratory-scale biogas digesters in this study were fed with substrates from a foaming-prone full-scale biogas plant containing the filamentous bacterium M....
Article
Resources in used water are at present mainly destroyed rather than reused. Recovered nutrients can serve as raw material for the sustainable production of high value bio-products. The concept of using hydrogen and oxygen, produced by green or off-peak energy by electrolysis, as well as the unique capability of autotrophic hydrogen oxidizing bacter...
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17á-Ethinylestradiol (EE2) is a synthetic estrogen, which is found to resist biodegradation. It has been observed that EE2 eludes treatment in most conventional treatment facility. Batch experiments on the biological removal of EE2 and Bisphenol A (BPA) using a highly active nitrifying liquid inoculum (NLI) was investigated. NLI had shown the capac...
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A biosorptive activated sludge (BAS) was operated at lab-scale with diluted and concentrated municipal wastewater to study the efficiency of removal of organics (particulate and soluble COD) and recovery of nutrients (TKN, ammonia, phosphorus). The system performed significantly better with concentrated wastewater, where COD removal efficiency was...
Article
Biofouling is a major challenge in the water industry and public health. Silver nanoparticles (AgNPs) have excellent antimicrobial properties and are considered to be a promising anti-biofouling agent. A modified method was used to produce small sized and well-dispersed biogenic silver nanoparticles with a mean size of ~6 nm (Bio-Ag0-6) using Lacto...
Article
Microcapsules were applied to encapsulate bacterial spores for self-healing concrete. The viability of encapsulated spores and the influence of microcapsules on mortar specimens were investigated first. Breakage of the microcapsules upon cracking was verified by Scanning Electron Microscopy. Self-healing capacity was evaluated by crack healing rati...
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Countries of Southern Europe are currently suffering from severe socio-economic pain resulting from high debt levels and austerity measures which constrain investment in innovation-based recovery strategies that are essential for entry into a long-term sustainable period of increasing employment and wealth creation. Young university-educated people...
Article
The microbial community composition in a full-scale biogas plant fed with sewage sludge and fat, oil and grease (FOG) was investigated over a 15-month period, including two foam formation events. Addition of FOG as a substrate in the biogas plant together with high abundances of Microthrix parvicella were found to promote foam formation in the down...
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The concern about phosphorus depletion is driving more efficient phosphorus use and recycling. In this context the precipitation of phosphate as struvite from wastewaters has recently gained considerable traction. This study investigates the influence of different parameters on the ureolytic phosphate precipitation (pH increase by means of urease a...
Article
Anaerobic digestion yields effluents rich in ammonium and phosphate and poor in biodegradable organic carbon, thereby making them less suitable for conventional biological nitrogen and phosphorus removal. In addition, the demand for fertilizers is increasing, energy prices are rising and global phosphate reserves are declining. This requires both c...
Article
A simple measuring system was developed that yields information about the presence of NH+4 and NO−2 nitrogen in mixed liquor samples. In addition, it allows monitoring of the rate of both NH+4 and NO−2 oxidation simultaneously with the carbon substrate oxidation using OUR measurements. The method is based on the subsequent addition of NaClO3 and al...
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A brief overview of methods and sensors to characterize activated sludge is presented, summarizing techniques related to two important activated sludge processes: biological nitrogen removal (nitrification and denitrification) and sludge settling. Traditional off-line methods, typically applied in a laboratory environment to determine nitrifying/de...
Article
Bacterially induced carbonate precipitation has been explored for the protection and consolidation of ornamental stone. Attempts to improve the efficiency of this biodeposition process were primarily focused on the microbial aspects, i.e. type of microorganism and metabolic pathway. In this study, the influence of the chemical parameters, i.e. conc...
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Pre-concentration of municipal wastewater by chemically enhanced primary treatment (CEPT) was studied under controlled laboratory conditions. Both iron and aluminium-based coagulants were examined at gradually increasing concentrations (0.23, 0.35, 0.70 and 1.05 mmol/L). The CEPT sludge generated from different coagulation experiments was digested...
Article
The discharge of nitrogen is increasingly restricted. The autotrophic nitrogen removal process, which combines partial nitritation and anaerobic ammonium oxidation (Anammox), is recommended for high ammonium loaded streams with no or low organic carbon content because of the lower operational costs. However, the cultivation and start-up period can...
Article
Early warning indicators for process failures were investigated to develop a reliable method to increase the production efficiency of biogas plants. Organic overloads by the excessive addition of rapeseed oil were used to provoke the decrease in the gas production rate. Besides typical monitoring parameters, as pH, methane and hydrogen contents, bi...
Article
The removal of phosphate as magnesium ammonium phosphate (MAP, struvite) has gained a lot of attention. A novel approach using ureolytic MAP crystallization (pH increase by means of bacterial ureases) has been tested on the anaerobic effluent of a potato processing company in a pilot plant and compared with NuReSys(®) technology (pH increase by mea...
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Door de stijging van de energieprijzen en de verhoogde noodzaak voor groene energie zit energieherwinning via biogasproductie uit afvalstromen in de lift. De biogasinstallaties voor het verwerken van groente-, fruiten tuinafval (GFT-afval) hebben als hoofdfocus groene energieherwinning, maar ook bij mestverwerking, industriële en huishoudelijke afv...
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About 30 full-scale partial nitritation/anammox plants are established, treating mostly sewage sludge reject water, landfill leachate or food processing digestate. Although two-stage and one-stage processes each have their advantages, the one-stage configuration is mostly applied, termed here as oxygen-limited autotrophic nitrification/denitrificat...
Article
Solar disinfection (SODIS) is a very inexpensive and easy-to-run water-treatment process that is widely used in third world countries to decrease the number of waterborne diseases and mortality. However, it does have a number of disadvantages, including the long time needed for complete disinfection, especially during cloudy days, and the possible...
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Crack repair is crucial since cracks are the main cause for the decreased service life of concrete structures. An original and promising way to repair cracks is to pre-incorporate healing agents inside the concrete matrix to heal cracks the moment they appear. Thus, the concrete obtains self-healing properties. The goal of our research is to apply...
Article
This study describes the microbial community richness, -dynamics, and -organization of four full-scale anaerobic digesters during a time-course study of 45 days. The microbial community was analyzed using a Bacteria- and Archaea-targeting 16S rRNA gene-based Terminal-Restriction Fragment Length Polymorphism approach. Clustering analysis separated m...
Article
To study the potential biocontrol activity of bioflocs technology. Glycerol-grown bioflocs were investigated for their antimicrobial and antipathogenic properties against the opportunistic pathogen Vibrio harveyi. The bioflocs did not produce growth-inhibitory substances. However, bioflocs and biofloc supernatants decreased quorum sensing-regulated...
Conference Paper
The performance and stability of a domestic sewage treatment system consisting of an upflow anaerobic sludge blanket (UASB) reactor were assessed. This was to come up with a technical evaluation of using such a system to treat directly such wastewater containing high amounts of suspended solids (SS), in developing countries like Lesotho. Through ti...
Article
Sustainable wastewater treatment requires that household wastewater is collected and treated separately from industrial wastewater and rainwater run-offs. This separate treatment is, however, still inadequate, as more than 70% of the nutrients and much of the chemical oxygen demand (COD) and potential pathogens of a domestic sewage system are confi...
Conference Paper
The presence of enteric viruses in drinking water is a potential health risk. Growing interest has arisen in nanometals for water disinfection, in particular the use of silver based nanotechnology. In this study, Lactobacillus fermentum served as reducing agent and bacterial carrier matrix for zerovalent silver nanoparticles, referred to as biogeni...
Article
In this work, chocolate has been evaluated as a potential protective carrier for oral delivery of a microencapsulated mixture of Lactobacillus helveticus CNCM I-1722 and Bifidobacterium longum CNCM I-3470. A sequential in vitro setup was used to evaluate the protection of the probiotics during passage through the stomach and small intestine, when e...
Article
The oleochemical industry is currently still dominated by conventional chemistry, with biotechnology only starting to play a more prominent role, primarily with respect to the biosurfactants or lipases, e.g. as detergents, or for biofuel production. A major bottleneck for all further biotechnological applications is the problem of the initial mobil...
Data
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Supplementary information. Figure S1, discussion of Figure S1, and Table S1.
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Microbial denitrification is not considered important in human-associated microbial communities. Accordingly, metabolic investigations of the microbial biofilm communities of human dental plaque have focused on aerobic respiration and acid fermentation of carbohydrates, even though it is known that the oral habitat is constantly exposed to nitrate...
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Deammonification involves the combined application of aerobic and anoxic ammonium-oxidizing bacteria (AerAOB & AnAOB) and allows to treat wastewaters with a high ammonium concentration in a sustainable and cost-efficient way. So far, it could take more than one year to start up the process, even with the addition of AnAOB enriched inocula. In contr...