Functional display of ice nucleation protein InaZ on the surface of bacterial ghosts

Bioengineered. 2017 Sep 3;8(5):488-500. doi: 10.1080/21655979.2017.1284712. Epub 2017 Jan 25.


In a concept study the ability to induce heterogeneous ice formation by Bacterial Ghosts (BGs) from Escherichia coli carrying ice nucleation protein InaZ from Pseudomonas syringae in their outer membrane was investigated by a droplet-freezing assay of ultra-pure water. As determined by the median freezing temperature and cumulative ice nucleation spectra it could be demonstrated that both the living recombinant E. coli and their corresponding BGs functionally display InaZ on their surface. Under the production conditions chosen both samples belong to type II ice-nucleation particles inducing ice formation at a temperature range of between -5.6 °C and -6.7 °C, respectively. One advantage for the application of such BGs over their living recombinant mother bacteria is that they are non-living native cell envelopes retaining the biophysical properties of ice nucleation and do no longer represent genetically modified organisms (GMOs).

Keywords: bacterial ghosts; ice nucleation; ice nucleation protein.

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Outer Membrane Proteins / genetics*
  • Cell Extracts / chemistry
  • Cell Extracts / genetics
  • Cell Membrane / chemistry*
  • Cell Membrane / genetics*
  • Escherichia coli / chemistry*
  • Escherichia coli / genetics
  • Ice
  • Pseudomonas syringae / chemistry
  • Pseudomonas syringae / physiology*


  • Bacterial Outer Membrane Proteins
  • Cell Extracts
  • Ice
  • ice nucleation protein