Antibiotic Bacillomycin D Affects Iron Acquisition and Biofilm Formation in Bacillus velezensis through a Btr-Mediated FeuABC-Dependent Pathway

Cell Rep. 2019 Oct 29;29(5):1192-1202.e5. doi: 10.1016/j.celrep.2019.09.061.

Abstract

Bacillus spp. produce a wide range of secondary metabolites, including antibiotics, which have been well studied for their antibacterial properties but less so as signaling molecules. Previous results indicated that the lipopeptide bacillomycin D is a signal that promotes biofilm development of Bacillus velezensis SQR9. However, the mechanism behind this signaling is still unknown. Here, we show that bacillomycin D promotes biofilm development by promoting the acquisition of iron. Bacillomycin D promotes the transcription of the iron ABC transporter FeuABC by binding to its transcription factor, Btr. These actions increase intracellular iron concentration and activate the KinB-Spo0A-SinI-SinR-dependent synthesis of biofilm matrix components. We demonstrate that this strategy is beneficial for biofilm development and competition with the Pseudomonas fluorescens PF-5. Our results unravel an antibiotic-dependent signaling mechanism that links iron acquisition to biofilm development and ecological competition.

Keywords: Bacillus; FeuABC; bacillomycin D; biofilm; interspecific competition; iron uptake; transcription factor Btr.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Antimicrobial Cationic Peptides / pharmacology*
  • Bacillus / drug effects
  • Bacillus / physiology*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Biofilms / drug effects
  • Biofilms / growth & development*
  • Biological Transport / drug effects
  • Iron / metabolism*
  • Models, Biological
  • Mutation / genetics
  • Operon / genetics
  • Oxidation-Reduction
  • Protein Binding / drug effects
  • Pseudomonas fluorescens / drug effects
  • Species Specificity
  • Transcription Factors / metabolism
  • Up-Regulation / drug effects

Substances

  • Anti-Bacterial Agents
  • Antimicrobial Cationic Peptides
  • Bacterial Proteins
  • Transcription Factors
  • bacillomycin D
  • Iron