Swammerdam Institute for Life Sciences

Research lines Molecular Biology and Microbial Food Safety

Outline of the different research themes MBMFS

In this Powerpoint presentation the different themes of the researchgroup MBMFS are outlined

Main theme is:

Stress response in biomedical systems

The basics of biological responses to stress

An overriding issue in biology is stress response to environmental challenge. We study this response at the level of cellular bioenergetics and pH homeostasis in the context of growth and (controlled) cell death. As modelsystems Saccharomyces cerevisiae and Caenorhabditis elegans,as a simple multicellular model, are used. Focus is on the role of mitochondria in ROS formation and real-time measurement of the behaviour of the intracellular pH in the cytosol and the mitochondria of live cells. Clinically relevant examples are the study of the molecular basis of ageing, side effects of anti-retroviral medication as well as the responses to conditions typically found in body niches occupied by pathogenic organisms. In our studies we address the hierarchy in decision making focussing on genome, transcript and proteome analyses as well as quantitative physiology.

Funded by University funds, McGillarvy fellowship, Nuffic

Reaction of food spoilage and pathogenic yeasts to environmental stress


The interaction of bakers yeast (Saccharomyces cerevisiae) with weak organic acids, prominent in the food industry and Candida albicans with medically relevant conditions is studied. Prime focal points are thermal and weak-organic acid stress response as well as resistance development against common azole antifungals. We analyse the behaviour of cells growing both planktonically in well defined culture media as well as cells growing in mono-species biofilms. In our experimental set-up we focus on analysing and subsequently providing targets for interfering with stress (cross-)tolerance mechanisms. For proteomic analyses of the response of yeast to environmental stress we collaborate extensively with the department of Mass Spectrometry of Biomacromolecules  at SILS.

Funded by EU-FP7 Marie Curie, Nuffic

Reaction of food spoilage & pathogenic bacteria to environmental stress

(i) Bacterial spore formers

The behavior of aerobic spore formers, both lab-strain and food spoilage Bacillus subtilis strains, is studied. These are spoilage organisms of prime-importance to the food industry due to their highly stress resistant endospores. Their occurrence necessitates the application of harsh food preservation processes such as high thermal treatments. The mechanistic basis of their extreme high thermal resistance (some for various minutes at 121ªC) as well as the molecular mechanisms involved in the early phases of spore germination and outgrowth under optimal and sub-optimal environmental conditions, are still far from mechanistically understood. We focus on analysis of thermally stressed spores growing out under weak-organic acid preservative stress. The data provide new targets for the enhancement of the efficacy of weak-organic acids as food preservative. For proteomic analyses of the spore coat we collaborate extensively with the department of 'Mass Spectrometry of Bio-macromolecules' at SILS.

(ii) Models for antibiotic resistance development

Bacteria of relevance to microbial food safety are prone to acquire resistance towards environmental conditions such as the use of antibiotics in animal feed practices. Such events create potentially harmful situations to the medical field as multiple antibiotic resistance development may occur and could well harm the effective use of these antibacterial agents in treating infection.
Our group focuses on the development of systems to study (1) acquisition of antibiotic resistance, (2) transmission of antibiotic resistance, (3) loss of antibiotic resistance. For all scientific questions we make use of well accessible model systems (primarily Escherichia coli) and controlled culture conditions (fermentors and chemostats). This research is led by Dr. Benno Ter Kuile of the Dutch Food Safety Authority (NVWA) who holds a part-time research position at our department.

Funded by NWO-STW, FES, EU Erasmus Mundus & NVWA

Scientific Cooperation Medical Microbiology AMC

Medical Microbiology is the field of research in which molecular and physiological tools are used to unravel the behaviour of disease causing microorganisms. We focus on the response of the organisms to antimicrobial agents and adverse environmental conditions. The studies naturally have both a fundamental and an applied angle. At MBMFS our focus is primarily on the fundamental aspects of the behaviour of medically relevant yeasts and bacteria. Model organisms are studied under defined laboratory conditions and environmental stressful conditions as they occur upon infection are as much as possible simulated. This includes the study of responses to increased temperature, presence of acidity and low pH values as well as the presence of antibiotics and antimycotics. In collaboration with companies we aim at identifying novel targets that can be exploited. Together with the department for Medical Microbiology at the Academic Medical Centre (AMC) we are currently intensifying our research collaboration on understanding the basics of the antimicrobial activity of honey. Thereby we provide studies to understand the molecular basis of damage and response to arrive at approaches to inhibit drug resistant bacteria in clinically relevant settings.

Grant requests to NWO-STW

Published by  Swammerdam Institute

11 January 2017