Biology subjects

van Wijngaarden, E. W.

Publications and source records attributed to van Wijngaarden, E. W..

4 recordsLinked to original sources

bioRxiv2026

Rheinheimera sp. T2C2 Bacterial Biofilm for Bioremediation of Cobalt (II)

Toxic metals, including cobalt, are often the cause of contamination of rivers and lakes in mining regions. Heavy metal water pollution has been linked to numerous human health problems, prompting the need for environmental remediation. Existing techniques for removing heavy metals from water, such as chemical precipitation and filtration, produce toxic waste, are costly, or require high power consumption for pumping. Biosorption is a potential alternative strategy that is cost-effective and uses readily available and naturally produced biomass and living material to absorb pollutants. Engineering living materials, such as biofilms, which consist of living cells and a secreted polymer matrix, offer potential to integrate toxin sensing, sequestration, and metabolism capabilities of cells to improve pollution remediation strategies. New biofilm producing candidates need to be explored to implement these material capabilities. Previous biosorption studies have primarily used bacterial biofilms from known pathogens and/or generate toxic waste in the form of the absorbent material combined with the heavy metal. Here, we describe a newly isolated bacterium called Rheinheimera sp. T2C2 that forms biofilms with promising biosorption characteristics. T2C2 is a non-pathogenic, aquatic bacterium with low nutrient requirements and high biofilm production. We demonstrate 1) the efficacy of Rheinheimera sp. T2C2 as a biosorbent for cobalt bioremediation; 2) how biosorption is altered by water conditions to establish the efficacy of this strategy in different environments; and 3) how the metal can be released from the biofilm for metal recycling. Our findings will provide a living materials strategy that overcomes existing barriers for bioremediation, and improve the health of ecosystems and humans through heavy metal removal and recycling.

microbiology↗

bioRxiv2025

Environmental factors drive bacterial degradation of gastrointestinal mucus

The mucus layer lining the gastrointestinal tract is essential for gut health, providing a protective barrier against pathogens while maintaining symbiosis with the microbiome. Its disruption is a hallmark of gastrointestinal diseases like ulcerative colitis. While glycan foraging by gut bacteria is thought to initiate mucus disruption, its impact on mucus structural properties remains poorly understood, largely due to the lack of physiologically relevant models. To address this gap, we developed a method to collect human-cell-derived mucus that closely mimics the mechanical properties of human colonic mucus. Using this system, we investigated mucus utilization and degradation by a panel of commensal bacteria with distinct metabolic profiles. Glycan utilization by species such as Bacteroides thetaiotaomicron and Bacteroides fragilis showed no correlation with changes in mucus rheology. Instead, secreted proteases were identified as the primary driver of mucus degradation. Protease activity by B. fragilis and Bifidobacterium longum was influenced by nutrient availability, whereas in Enterococcus faecalis, it was additionally affected by oxygen exposure. E. faecalis also adapted to oxidative stress by enhancing carbohydrate metabolism and upregulating several virulence genes. Together, our findings reveal that bacterial mucus degradation is context-dependent and shaped by environmental factors. This study provides key insights into the mechanisms underlying mucus degradation and underscores the value of human cell-derived mucus models for understanding bacteria-mucus interactions in health and disease.

microbiology↗

bioRxiv2024

Engineering Bacterial Biomanufacturing: Characterization and Manipulation of Sphingomonas sp. LM7 Extracellular Polymers

Biologically produced materials are an attractive alternative to traditional materials such as metals and plastics and offer improved functionalities such as better biodegradability and biocompatibility. Polysaccharides are an example of a biologically produced materials that can have a range of chemical and physical properties including high stiffness to weight ratios and thermal stability. Biomanufactured bacterial polysaccharides can come with many advantages such as being non-toxic and are mechanically robust relative to proteins and lipids, which are also secreted by bacteria to generate a biofilm. One major goal in biomanufacturing is to produce quality material quickly and cost-effectively. Biomanufacturing offers additional benefits compared to traditional manufacturing including low resource investment and equipment requirements, providing an alternative to sourcing fossil fuel byproducts, and relatively low temperatures needed for production. However, many biologically produced materials require complex and lengthy purification processes before use. This paper 1) identifies the material properties of a novel polysaccharide, dubbed promonan, isolated from the extracellular polymeric substances of Sphingomonas sp. LM7; 2) demonstrates that these properties can be manipulated to suit specific applications; and 3) presents two alternative methods of processing to shorten purification time by more than 50% while maintaining comparable material.

biophysics↗

bioRxiv2023

Solute Transport in Engineered Living Materials using Bone Inspired Microscale Channel Networks

Engineered living materials (ELMs) are an emerging class of materials that is synthesized and/or populated by living cells. Maintaining living cells within an ELM over prolonged periods remains a major technical challenge that limits the service life of a material. Biological materials regularly maintain robust populations of living cells. Bone maintains living cells for decades by delivering nutrients through a network of nanoscale channels punctuated by microscale pores. Nutrient transfer in bone is enabled by mechanical loading experienced during regular use. Here we identify the characteristics of channel-pore network geometries and external mechanical loading that can be used in engineered living materials to deliver nutrients to resident cell populations. Transport occurs when deformation in the microscale pore network exceeds the volume of the connecting channels. Computational models show that transport is enhanced at greater load magnitudes and lower loading frequencies and are consistent with experimental validation using microfluidic systems. Our findings provide quantitative design principles for channel-pore networks capable of delivering nutrients to materials designed to house living cells.

bioengineering↗