Enhancing phosphorus removal of photogranules by incorporating polyphosphate accumulating organisms

Photogranules are a novel wastewater treatment technology that can utilize the sun's energy to treat water with lower energy input and have great potential for nutrient recovery applications. They have been proven to efficiently remove nitrogen and carbon but show lower conversion rates for phosphorus compared to established treatment systems...

Multiscale models driving hypothesis and theory-based research in microbial ecology

Hypothesis and theory-based studies in microbial ecology have been neglected in favour of those that are descriptive and aim for data-gathering of uncultured microbial species. This tendency limits our capacity to create new mechanistic explanations of microbial community dynamics, hampering the improvement of current environmental...

Prospects for multi-omics in the microbial ecology of water engineering

Advances in high-throughput sequencing technologies and bioinformatics approaches over almost the last three decades have substantially increased our ability to explore microorganisms and their functions – including those that have yet to be cultivated in pure isolation. Genome-resolved metagenomic approaches have enabled linking powerful...

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

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....

Enrichment and Aggregation of Purple Non-sulfur Bacteria in a Mixed-Culture Sequencing-Batch Photobioreactor for Biological Nutrient Removal From Wastewater

Mixed-culture biotechnologies are widely used to capture nutrients from wastewater. Purple non-sulfur bacteria (PNSB), a guild of anoxygenic photomixotrophic organisms, rise interest for their ability to directly assimilate nutrients in the biomass. One challenge targets the aggregation and accumulation of PNSB biomass to separate it from the...

Effects of cold recovery technology on the microbial drinking water quality in unchlorinated distribution systems

Drinking water distribution systems (DWDSs) are used to supply hygienically safe and biologically stable water for human consumption. The potential of thermal energy recovery from drinking water has been explored recently to provide cooling for buildings. Yet, the effects of increased water temperature induced by this “cold recovery” on the...

Impact of Distribution and Network Flushing on the Drinking Water Microbiome

We sampled the tap water of seven unique, full-scale drinking water distribution systems at different locations as well as the corresponding treatment plant effluents to evaluate the impact of distribution and the potential presence of a core drinking water microbiome. The water was also sampled during network flushing to examine its effect on...

Metatranscriptomics reveals the molecular mechanism of large granule formation in granular anammox reactor

Granules enriched with anammox bacteria are essential in enhancing the treatment of ammonia-rich wastewater, but little is known about how anammox bacteria grow and multiply inside granules. Here, we combined metatranscriptomics, quantitative PCR and 16S rRNA gene sequencing to study the changes in community composition, metabolic gene...

Prevalence of ‘Candidatus Accumulibacter phosphatis’ type II under phosphate limiting conditions

P-limitation in enhanced biological phosphorus removal (EBPR) systems fed with acetate, has generally been considered as a condition leading to enrichment of organisms of the genotype’ Candidatus Competibacter phosphatis’ expressing the glycogen-accumulating organisms (GAO) phenotype. Recent studies have demonstrated in short-term experiments...

Enhanced Biological Phosphorus Removal: Metabolic Insights and Salinity Effects

Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison to physical and chemical phosphorus removal...

Microbial Ecology of Accelerated Low Water Corrosion

Bacterial Societies: Cooperation, Colonization, and Competition in Micro-Scale Ecosystems

In this thesis, I describe experiments aimed at understanding bacterial population dynamics in ecosystems that are spatially structured at the micro-scale. We combine microfabrication and microfluidics to create synthetic ecosystems that have a complex yet well-defined geometry and chemical composition. Bacteria that inhabit such ecosystems can...

Microbial ecology of phototrophic biofilms

Biofilms are layered structures of microbial cells and an extracellular matrix of polymeric substances, associated with surfaces and interfaces. Biofilms trap nutrients for growth of the enclosed microbial community and help prevent detachment of cells from surfaces in flowing systems. Phototrophic biofilms can best be defined as surface...

Co-existence of physiologically similar sulfate-reducing bacteria in a full-scale sulfidogenic bioreactor fed with a single organic electron donor