Bacteria have the ability to alter their morphology in order to adapt to changing environments.

During the Leiden Science Family Day, you can take part in various workshops. You can also watch various demonstrations. Where will you go?

Human and animal cells are very complex: very different chemical processes are going on at the same time, but they are separated from each other because the cells are divided in compartments. These compartments may also have a profound effect on the potential efficacy of therapeutics, because the drug…

Bacteria are highly complex and diverse organisms that have adapted to survive in ecological niches ranging from the most extreme to the most heterogeneous environments.

Microbial Sciences' contribution to the Host-Microbe Interactions research theme is to investigate how beneficial or disease-causing microbes associate and interact with their host.

Bacteria often experience external challenges, such as changes in environmental conditions or attacks by bacteriophages.

Antibiotics are a class of medicine most people take for granted. But pathogenic bacteria are becoming more and more resistant to our antibiotics, and this poses a great challenge for future treatments. There is thus a great societal need to identify new molecules that can address new targets and be…

German scientists and NASA have developed a bacteria-killing coating for space toilets. With this coating they hope to protect astronauts in space stations from pathogens. Professor of Biological chemistry Nathaniel Martin sheds light on the discovery: 'You don't expect nasty bacteria up there, but…

Living systems scale from unicellular microbes to complex multispecies communities that constantly change over time. Within the theme Development & Disease, we enhance our fundamental understanding of development and homeostasis of living cells and systems. We analyze the normal situation and how stresses…

Three Leiden researchers will each receive a Vici grant of 1.5m euros. They are historian Cátia Antunes, cell biologist Dennis Claessen and archaeologist Marie Soressi. This grant from the Dutch Research Council (NWO) will give them the opportunity to form their own research group over the next five…

Identifying natural plant-associated bacteria that provide targeted inhibition of pathogens through the production of antimicrobial peptides.

In order to gain insight into the structure and function of the molecular complexes involved in chemotaxis, we use electron cryotomography (ECT). This technique allows us to directly study microbes in their native state at resolutions capable of visualizing individual proteins.

Leiden was European City of Science in 2022: for a year Leiden was the capital of European science. Leiden University was a proud partner of Leiden2022.

Vancomycin is a last-resort antibiotic for the treatment of many Gram-positive bacterial infections, while remaining inactive against Gram-negative strains.

The increasing resistance of pathogenic bacteria to antibiotics necessitates the discovery of new medicines.

Antibiotic resistance, caused by widespread use of antibiotics, leads to bacterial infections that are difficult, if not impossible, to treat and is a major worldwide health concern.

β-Lactamases are enzymes that can break down β-lactam substrates, such as antibiotics, preventing the use of these antibiotics for the treatment of various infectious diseases. However, some compounds, β-lactamase inhibitors, can block these enzymes allowing for possible treatments using a combination…

Promotor: G.P. van Wezel, Co-promotor: D. Claessen

The soil-dwelling, filamentous bacteria of the genus Streptomyces are renowned for their production of useful secondary metabolites including antibiotics. The work described in this thesis provides new insights on the role and regulation of antibiotic production and resistance in these bacteria.

In this thesis, I focused on studying the above- and belowground interactions of J. vulgaris from a plant-soil feedback (hereafter, PSF) perspective. I investigated the temporal variation of negative PSF and examined the effects of root-associated bacteria on plant performance and aboveground herbiv…

Plants are colonized by an astounding number of microorganisms that can provide different life-support functions, including nutrient acquisition and protection against (a)biotic stresses like drought or pathogen attack.

Promotor: Prof.dr. T. Schmidt

Macromolecular Biochemistry is a section of the Leiden Institute of Chemistry at Leiden University, comprising the PIs Marcellus Ubbink, Remus Dame, Lars Jeuken, Anne Wentink, Anjali Pandit, René Olsthoorn, Alia Matysik, Sebastian Geibel and Steffen Brünle.

Bacteria are everywhere. They are the most abundant organisms on earth and impact all aspects of our lives. They determine our health and shape our environment. Ariane Briegel, professor of Ultrastructural Biology, freezes bacteria super fast to gain a true-to-nature image of the internal and external…

The central aims of MicroClock project are to describe the B. subtilis circadian clock at molecular and functional levels, and discover the mechanisms of clock-regulated bidirectional signaling between B. subtilis and the model plant Arabidopsis

The CMCB comprises research groups from the Institute of Biology Leiden (IBL), the Leiden Institute of Chemistry (LIC) and the Leiden University Medical Center (LUMC).

The Quantitative Pharmacology group headed by Coen van Hasselt focusses on the application of state-of-the-art quantitative pharmacometrics and systems pharmacology modeling combined with translational experimental models to develop personalized treatment strategies for antibiotics and to combat antimicrobial…

Microbes influence and respond to other organisms. This theme explores the dynamic relationships within plant and animal microbiomes, and the immune responses that govern host defense. Using model systems such as zebrafish, insects, and plants, we investigate fundamental processes and engineer microbes…

Microbial Sciences' contribution to the Biodiversity & Evolution research theme focuses on understanding how bacteria sense and respond to their environment, and how bacterial diversity and evolution is influenced by cooperative and antagonistic interactions taking place between microbes.

Edith Schippers, Minister of Health, will be investing six million euros over the coming four years to boost research on new antibiotics. The programme will be set up by several different parties, including the Leiden Centre for Antimicrobial Research.

Bacteria in the teeth tell us a lot about nutrition and disease in our ancestors. It also tells us more about the immune system. This provides clues for treating modern diseases and allergies. For a long time archaeologists were irritated by tartar on the teeth of excavated skulls. They thought that…

The genomic DNA of every organism is organized and compacted in order to fit inside the cell. This is achieved by the joint action of numerous architectural proteins that aid in folding the genome. Genome folding is tightly interconnected with transcription, with genes in certain regions being silenced,…

Vaccines are an extraordinary category of biopharmaceuticals. They are usually prophylactic and come in many types, from whole bacteria to peptides and nucleic acids. They are very cost effective and almost every human on the planet is vaccinated. The latter mandates that vaccines have to be extremely…

Our immune system protects us against disease, but every now and then, something goes wrong: an enemy invades our bodies or our immune system attacks our own cells and we become ill. Doctors and researchers at the Leiden University Medical Center (LUMC) want to be able to manipulate the immune system…

We investigate bacteria and fungi to understand their malicious or beneficial impact on food crops and their pathogenic or antibiotic role in human health.

The CIGR comprises research groups from the Leiden Institute of Chemistry (LIC), the Leiden Academic Centre for Drug Research (LACDR) and the Leiden Institue of Physics (LION).

On this page, you will find the recordings of the Tuesday Talks since April 2025. Recordings of the precursor to the Tuesday Talks, This Week’s Discoveries, are also available here.

The CIGR brings together a diverse range of unique expertise in genome research rooted in biology, chemistry and physics. Members of the CIGR investigate genome folding and genome transactions. An important aspect is direct as well as long term relevance for medicine.

We showed that constitutive and inducible chemical and morphological defenses against Western flower thrips differ between tomato and chrysanthemum plants.

Almost all bacteria are enveloped by a cell wall that provides cellular protection.

Given the accelerating appearance of antimicrobial resistance, there is an urgent need for more fundamental research into novel antibiotic strategies. The work in this thesis helps to address this global problem by developing new antibiotic compounds, inspired by the antibacterial mechanisms of the…

Cities need to become greener, more biodiverse, and climate-resilient. However, many organisms that are vital for the functioning of urban green spaces and the wellbeing of urban citizens remain largely unknown.

This thesis investigates the relations between metabolism and anatomy through the use of Magnetic Resonance Imaging (MRI).

Soil ecologists Emilia Hannula (Leiden) and Elly Morriën (UvA) received the Golden Medal of Teylers Tweede Genootschap on 5 November. They received the prize for their submission to a competition on sustainable soil management.

We aim to provide new insights relating to the spectacular multi-cellular life cycle of streptomycetes and other actinobacteria.

By carrying out fundamental research and providing excellent education, universities become a breeding ground for innovation and entrepreneurship.

Learning from nature and utilizing microbial biodiversity to identify and characterize enzymes for degradation and upcycling of plastics and other polymeric materials.

To get a feeling of how we operate at LED3 when it comes to Early Drug Discovery, please browse through our case studies. When you select a case study you’ll find relevant contacts.

The long-held desire - to link structure directly to function and to explain molecular mechanisms based on basic chemical or physical principles - is finally coming closer, satisfying not only our scientific curiosity but also offering new solutions to the many challenges in the field of health, energy…

Promotores: Prof.dr. H.P. Spaink & Prof.dr. P.C.W. Hogendoorn, Co-promotor: Dr. M.J.M. Schaaf