Genetically modified bacteria

Customized design of bacterial strains

The development of genetic engineering and synthetic biology allows us today to modify the genome of microorganisms and optimize their metabolic properties or to equip them with alternative or new pathways. Keeping this in mind, SMALTIS has been developing a set of tools to modify the genome of bacteria. 

We use methods adapted to each individual project, allowing us to precisely modify bacterial genome.

-Guarantees: no scars or resistance cassettes
-Quality control: PCR & Sanger sequencing
-Deliverables: genetically modified strains (vials or conservation agar)
-Time of construction: 4 weeks

Today, our method has already proven its worth with the following species:
      – Achromobacter insuavis
      – Acinetobacter baumannii
      – Achromobacter xylosoxidans
      – Escherichia coli
      – Klebsiella pneumoniae
      – Pseudomonas aeruginosa
      – Pseudomonas fluorescens
      – Pseudomonas putida

If your species of interest happen not to be listed here, feel free to contact us to find out how we can help you.

Gene deletion

Deetion of a gene (CDS) or any specific DNA sequence giving the possibility of several applications such as:
      – The study of the functionality of a gene or protein of interest
      – The identification of gene regulation pathways

Example: construction of a BL21 E. coli strain, deleted in DE3 phage-sequence
Available Mutant: BL21∆DE3

Gene replacement

Replacement of a target gene with another gene of interest without changing the initial genetic environment.
Replacement of a gene of interest with a bioluminescent reporter gene, such as Green Fluorescent Protein (GFP), luxCDABE operon, or mCherry fluorescent protein, allows to study directly the modulation of gene expression, without resorting to real-time PCR technology, by quantifying light emitted. 

Example: replacement of a virulence gene of P. aeruginosa PAO1 strain with the Green Fluorescent Protein (GFP) coding gene.

Gene insertion

Insertion of DNA fragments directly into the chromosome of strains, thus creating new metabolic pathways.
These chromosome insertions are utterly stable and do not require any selection pressure (antibiotic or other) to be maintained in the long time. The creation of such strains may be considered a real alternative to the use of expression plasmids to produce recombinant proteins.
We can also “tag” strains by inserting a short DNA sequence in a specific spot of the chromosome, in order to differentiate them among other strains of the same species.

Example: creation of a bank of glow and fluorescent strains from so-called ESKAPE species (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter Baumannii, Pseudomonas aeruginosa and Enterobacter).

Mutagenesis directly on the chromosome

In order to check the impact of a mutation on the expression of genes or the functionality of proteins of interest, we are able to modify your chosen nucleotides directly on the chromosome of a strain. The insertion of stable mutation will allow not only to study the functionality of the variants of the same protein, but also to optimize the functionality of an enzyme by changing its active site.

Example: modification of specific nucleotides in the coding gene for the AmpC beta-lactamase of P. aeruginosa to assess the impact of potential mutations on the activity of the enzyme.