GROUP BARBIRZ / Project BA 4046/6-1

It’s sweet to move on – bacteriophage infection and processing of glycan-based biofilms

In many ecosystems, microorganisms shield themselves in biofilms, restricting access of bacterial viruses (bacteriophages) to their bacterial hosts. Goal of our project is to analyze bacteriophages and their glycan-depolymerases in glycan-dominated biofilms and their impact on viral infection dynamics in biofilms. Using bacteriophages that infect plant pathogens of the genus Erwinia as model system, we will employ fluorescence correlation spectroscopy (FCS) to study phage mobility and infection rate. We will include this data into theoretical models of population dynamics, with special emphasis on biofilm-dissipating depolymerases and their synergies in phage mixtures. As a prerequisite, we will develop an algorithm for depolymerase annotation from viral genomes, also to screen metagenomes for new viral depolymerases, in order to gain a deeper understanding of phage-host relationships in biofilms. The discovery of new biofilm depolymerases is highly desirable for biotechnology as antimicrobial agents active against biofilm-forming pathogens.

Figure 1: Viscous polysaccharides dominate biofilm matrices encountered by many bacteriophages. (A) In Pantoea stewartii biofilms, the exopolysaccharide stewartan confers high viscosity. (B) Single-particle trajectories of Salmonella phage P22 diffusing in a 20 mg/ml stewartan matrix. Arrows depict an immobile sub-population.

Principal Investigator(s)

Prof. Dr. Stefanie Barbirz
MSB Medical School Berlin
Hochschule für Gesundheit und Medizin
Rüdesheimer Straße 50
D-14197 Berlin


PhD student(s)



  • Irmscher T, Roske Y, Gayk I, Dunsing V, Chiantia S, Heinemann U, Barbirz S (2021) Pantoea stewartii WceF is a glycan biofilm modifying enzyme with a bacteriophage tailspike-like fold, J. Biol. Chem. 296, 100286. doi:10.1016/j.jbc.2021.100286
  • Dunsing V, Irmscher T, Barbirz S, Chiantia, S (2019) Purely Polysaccharide-Based Biofilm Matrix Provides Size-Selective Diffusion Barriers for Nanoparticles and Bacteriophages. Biomacromolecules, 20, 3842-3854. doi:10.1021/acs.biomac.9b00938