Single cell analysis of gene expression patterns of competence development and initiation of sporulation in Bacillus subtilis grown on chemically defined media

J Appl Microbiol. 2006 Sep;101(3):531-41. doi: 10.1111/j.1365-2672.2006.02911.x.


Aim: Understanding the basis for the heterogeneous (or bistable) expression patterns of competence development and sporulation in Bacillus subtilis.

Methods and results: Using flow cytometric analyses of various promoter-GFP fusions, we have determined the single-cell gene expression patterns of competence development and initiation of sporulation in a chemically defined medium (CDM) and in biofilms.

Conclusions: We show that competence development and initiation of sporulation in a CDM are still initiated in a bistable manner, as is the case in complex media, but are sequential in their timing. Furthermore, we provide experimental proof that competence and sporulation can develop under conditions that normally do not trigger these processes.

Significance and impact of the study: Some pathogens are able to develop natural competence, which is a serious medical problem with the increased acquired multi-drug resistance of these organisms. Another adaptive microbial response is spore formation. Because of their heat resistance and hydrophobicity, spores of a variety of species are of major concern for the food industry. Using the model organism B. subtilis, we show that competence development and sporulation are initiated in a bistable and sequential manner. We furthermore show that both processes may be noise-based, which has major implications for the control of unwanted differentiation processes in pathogenic and food-spoilage micro-organisms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Bacillus subtilis / genetics
  • Bacillus subtilis / physiology*
  • Bacterial Proteins / genetics
  • Biofilms
  • Cell Count
  • Culture Media
  • DNA, Bacterial / genetics
  • Flow Cytometry / methods
  • Gene Expression Regulation, Bacterial / genetics
  • Gene Expression Regulation, Bacterial / physiology*
  • Green Fluorescent Proteins / genetics
  • Mutation / genetics
  • Plasmids
  • Promoter Regions, Genetic / genetics
  • Spores, Bacterial / genetics
  • Spores, Bacterial / physiology
  • Transcription Factors / genetics


  • Bacterial Proteins
  • Culture Media
  • DNA, Bacterial
  • Transcription Factors
  • Green Fluorescent Proteins
  • comK protein, Bacillus subtilis