Plant-microbe interaction resulted in different physio/chemical responses by host plant and interacting rhizobacteria.

In this thesis, bioorthogonal chemistry is combined with correlative light-electron microscopy to selectively label and study pathogenic intracellular bacteria within the host immune cell.

Remus Dame

Extending our current arsenal of antibiotics is key to staying ahead in the arms race between humans and resistant bacteria.

Global healthcare is on the verge of an antibiotic availability crisis as bacteria have evolved resistance to nearly all known antibacterials. Identifying new antibiotics that operate via novel modes-of-action is therefore of high priority.

With the rise of multi-drug resistant bacterial pathogens, the possibility of a post-antibiotic world is quickly becoming reality.

The overall objectives of my thesis are to investigate the dynamics of the sorghum root microbiome and to explore the beneficial effects of the root microbiome on sorghum growth and stress tolerance.

The aim of this thesis is to study cell-cell interactions and the development of an assay to explore and quantify the exchange of membrane compounds.

A complex community of microbes develops in the infant gut shortly after birth. We call this community the infant gut microbiota. The microbiota influences the health of the infant, which makes the composition and function of the infant gut microbiota an important topic to study.

Streptomyces are bacteria abundant in soil that participate in diverse and complex interactions. These bacteria are the main producers of the antibiotics we currently use in the clinic.

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

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

Polymyxins are clinically used antibiotics, discovered in mid-20th century. Once abandoned due to excessive nephrotoxicity, they are now used increasingly to address infections caused by multi-drug resistant Gram-negative bacteria.In this thesis, we describe the development and synthesis of analogues…

Autophagy is a fundamental degradative process, maintaining cellular homeostasis and functions in host defense against intracellular pathogens, including mycobacteria and Salmonella.

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.

Antimicrobial drugs constitute a fundamental part of modern medicine. The global rise in antimicrobial resistance poses a major threat to global health.

Promotores: Prof.dr. H.J.M. de Groot, Prof.dr. J. Matysik (Universitaet Leipzig)

Promotores: Prof.dr. H. van Veen & Prof.dr. W. de Boer (Wageningen University)

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.

‘Werken in Leiden is een droom die uitkomt.’ Ákos Kovács studeerde in zijn geboorteland Hongarije en werkte in Duitsland, Denemarken en Groningen. Sinds september is hij hoogleraar Microbioom-ecologie bij het Instituut Biologie Leiden en hij werkt meteen volop met collega’s samen om ontdekkingen te…

Vinasse is a major by-product generated by the sugarcane biofuel industry. It is a source of microbes, nutrients and organic matter and often it is recycled as fertilizer.

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

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

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

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.

Promotor: Prof.dr. T. Schmidt

Streptomyces are filamentous bacteria that produce more than two-thirds of known antibiotics.

The filamentous bacteria Streptomyces are widespread inhabitants of terrestrial soils.

The type-IV secretion system (T4SS) is a machinery able to transfer DNA and proteins between bacteria and in certain cases also to eukaryotic cells.

Lezing, NGL-lezing

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.

Streptomyces are multicellular, Gram-positive bacteria in the phylum of actinobacteria which produce a high amount of bioactive natural products of which the expression is tightly coordinated with the life cycle.

The bacterial cell wall is a nearly universal structure that offers protection and gives the cell its shape. However, environmental stressors, such as cell wall-targeting antibiotics and hyperosmotic conditions, can induce bacteria to shift to a wall-deficient state. It is unknown whether the lack of…

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…

Actinobacteria are Gram-positive bacteria that have a complex multicellular life cycle and are well known for their ability to produce a wide range of bioactive natural products (NPs).

Bacterial chemosensory arrays are protein assemblies that are the key structural and functional component for motile bacteria to sense their internal or environmental chemical signals.

In populations with a seed-bank, individuals can temporarily become dormant and refrain from reproduction until they can become active again. The repository of all dormant individuals in the population is called the seed-bank. Seed-banks are observed in many taxa, including plants, bacteria and other…

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

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

Promotie

Promotie

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

Promotor: J.A. van Veen, Co-promotor: E.E. Kuramae

Streptomyces bacteria are a valuable source of natural products, many of which are used in the clinic or in biotechnology.

Promotor: G.A. van der Marel, Co-promotor: J.D.C. Codée

Promotor: G.P. van Wezel

Promotor: H.P. Spaink, Co-Promotor: A.H. Meijer

Promotor: Prof.dr. G.P. van Wezel

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…

Carbohydrates are present on the surface of bacteria making them suitable antigen candidates for vaccine development. This thesis deals with the synthesis of two carbohydrate-based components; the capsular polisaccharide of S. aureus type 5 and teichoic acids from staphilococci and enterococci speci…