The majority of clinically important antibiotics that are used to combat bacterial infections are derived from actinomycetes. In addition to antimicrobials, these organisms produce numerous enzymes for medical and technical applications. My team investigates how we can improve growth of these prolific bacteria for industrial applications. We therefore focus on cellular and physiological heterogeneity . Heterogeneity is observed between clonal mycelial particles, between different zones of colonies, between adjacent hyphae and even between adjacent compartments of individual hyphae. By dissecting the mechanisms underlying heterogeneity we aim to identify new targets to improve the exploitability of these bacteria as cell factories in the biotech sector.


  • Z. Zhang, S.S. Shitut, B. Claushuis, D. Claessen & D.E. Rozen (2022). Mutational meltdown of putative microbial altruists in Streptomyces coelicolor colonies. Nat Commun (in press).
  • Z. Zhang, C. Du, F. de Barsy, M. Liem, A. Liakopoulos, G.P. van Wezel, Y.H. Choi, D. Claessen and D.E. Rozen (2020). Antibiotic production in Streptomyces is organised by a division of labor through terminal genomic differentiation. Sci Adv 6: eaay5718
  • B. Zacchetti, H.A.B. Wösten & D. Claessen (2018). Multiscale heterogeneity in filamentous microbes. Biotech Adv 36: 2138-2149.
  • K. Ramijan, E. Ultee, J. Willemse, Z. Zhang, J.A.J. Wondergem, A. van der Meij, D. Heinrich, A. Briegel, G.P. van Wezel & D. Claessen (2018). Stress-induced formation of cell wall-deficient cells in filamentous actinomycetes. Nat Commun 9: 5164. 
  • B. Zacchetti, J. Willemse, B. Recter, D. van Dissel, G.P. van Wezel, H.A.B. Wösten & D. Claessen (2016). Aggregation of germlings is a major contributing factor towards mycelial heterogeneity of Streptomyces. Sci Rep 6: 27045.
  • G.J. van Veluw, M.L.C. Petrus, J. Gubbens, R. de Graaf, I.P. de Jong, G.P. van Wezel, H.A.B. Wösten & D. Claessen (2012). Analysis of two distinct mycelial populations in liquid-grown Streptomyces cultures using a flow cytometry-based proteomics approach. Appl Microbiol Biotechnol 96: 1301-1312.