PhD defence: The Bacterial Cell Envelope: Specific Labeling and Its Applications


The envelope of a bacterial cell is an essential structure of bacteria that varies between the different kinds of bacteria. It plays crucial roles in cell shaping, protection, and permeability modulation. The bacterial cell envelope is a key target for antibiotic development due to its unique components absent in mammalian cells, reducing the risk of toxicity. Therefore, detailed knowledge on the structure, organization and biogenesis of bacterial cell envelopes contributes to the development of new antibiotics. Fluorescent labeling of the bacterial cell envelope is an efficient way to decipher its biogenesis and can even serve as a method for developing new strategies to combat antibiotic-resistant pathogens.

In this dissertation, we aim to explore different methods to label different sub-structures and components of the envelope of bacteria to provide new methodologies to study its biogenesis. Lipopolysaccharide (LPS), a unique structure of the outer membrane of Gram-positive bacteria, was labeled with functionalized galactose commonly found in LPS of bacteria, providing a possible widely applicable method for labeling the outer membrane. Peptidoglycan was labeled via a modified glucosamine moiety for the first time. In addition, we designed a fluorogenic probe and demonstrated its application in testing the permeability of bacterial outer membranes. Further, based on our labeling methods, we developed new method of photodynamic inactivation of antibiotic resistant pathogens.

In conclusion, our successful labeling strategies expand the toolkit for studying bacteria and provide novel possibilities for addressing the challenges of combating antibiotic-resistant pathogens.

Start date and time
End date and time
Online (livestream link)
PhD candidate
Y. Xu
The Bacterial Cell Envelope: Specific Labeling and Its Applications
PhD supervisor(s)
prof. dr. R.J. Pieters
prof. dr. E.J. Breukink