Regulation of bacteria population behaviors by AI-2 "consumer cells" and "supplier cells"

BMC Microbiol. 2017 Sep 19;17(1):198. doi: 10.1186/s12866-017-1107-2.


Background: Autoinducer-2 (AI-2) is a universal signal molecule and enables an individual bacteria to communicate with each other and ultimately control behaviors of the population. Harnessing the character of AI-2, two kinds of AI-2 "controller cells" ("consumer cells" and "supplier cells") were designed to "reprogram" the behaviors of entire population.

Results: For the consumer cells, genes associated with the uptake and processing of AI-2, which includes LsrACDB, LsrFG, LsrK, were overexpressed in varying combinations. Four consumer cell strains were constructed: Escherichia coli MG1655 pLsrACDB (NK-C1), MG1655 pLsrACDBK (NK-C2), MG1655 pLsrACDBFG (NK-C3) and MG1655 pLsrACDBFGK (NK-C4). The key enzymes responsible for production of AI-2, LuxS and Mtn, were also overexpressed, yielding strains MG1655 pLuxS (NK-SU1), and MG1655 pLuxS-Mtn (NK-SU2). All the consumer cells could decrease the environmental AI-2 concentration. NK-C2 and NK-C4 were most effective in AI-2 uptake and inhibited biofilm formation. While suppliers can increase the environmental AI-2 concentration and NK-SU2 was most effective in supplying AI-2 and facilitated biofilm formation. Further, reporter strain, MG1655 pLGFP was constructed. The expression of green fluorescent protein (GFP) in reporter cells was initiated and guided by AI-2. Mixture of consumer cells and reporter cells suggest that consumer cells can decrease the AI-2 concentration. And the supplier cells were co-cultured with reporter cells, indicating that supplier cells can provide more AI-2 compared to the control.

Conclusions: The consumer cells and supplier cells could be used to regulate environmental AI-2 concentration and the biofilm formation. They can also modulate the AI-2 concentration when they were co-cultured with reporter cells. It can be envisioned that this system will become useful tools in synthetic biology and researching new antimicrobials.

Keywords: Autorinducer-2; Biofilm; “Consumer cells”; “Supplier cells”.

MeSH terms

  • Bacteria / growth & development
  • Bacteria / metabolism*
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Biofilms / drug effects
  • Biofilms / growth & development
  • Carbon-Sulfur Lyases / genetics
  • Carbon-Sulfur Lyases / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / growth & development
  • Escherichia coli / physiology*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial
  • Homoserine / analogs & derivatives*
  • Homoserine / analysis
  • Homoserine / genetics
  • Homoserine / metabolism
  • Lactones / analysis
  • Lactones / metabolism*


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Lactones
  • N-octanoylhomoserine lactone
  • Homoserine
  • Carbon-Sulfur Lyases
  • LuxS protein, Bacteria