LactXPress®

Our proprietary bacterial expression system [LactXpress®] represents an alternative & innovative expression system for the production of high-added-value recombinant proteins or peptides. 

This new protein production and secretion system combines inducible or constitutive expression and protein stability.

The major advantages of the LactXpress system over the other expression systems are:

• No endotoxins. "Endotoxin free" and "GRAS” (Generaly Recognized As Safe)  system.
• Easy downstream processing. Efficient secretion of proteins and limited endogenous proteins: the protein of interested is often more than 70% pure directly in the supernatant.
• Tightly controlled expression system. Both highly inducible and well repressed allowing production of toxic proteins or optimized constitutive promoter allowing continuous production strategy.
• Protease-free strain. A L. lactis htrA mutant strain, devoid of any surface protease, to increase heterologous protein yield and stability.
• Easy fermentation and scale-up. L.lactis is a microbial host with a very simple metabolism and rapid growth without aeration. The production volume can be readily scaled up from a few milliliters to thousands of liters in just one step.

Such a feasibility study typically comprises:

• Expression vector construction by either cloning the gene of interest directly from the source organism or synthetising of a codon-optimized gene (with an inducible or constitutive promoter, in fusion with L. lactis EXP4 signal peptide, with or without purification tags).
• Expression trial in wild-type and/or HtrA- (protease-free) strains. The expression study is carried out in mini-reactors (pH controlled) and analysed by standard protein analysis.
• Production of protein samples at 200 to 500 ml scale
• Report and documentation
   

• Optimisation of genetic constructs
• Optimisation and scale-up of the fermentation
• Development and scale-up of downstream processing and purification procedures
• Pilot productions up to 300L
• Technology transfer to cGMP producers

• Research licence
• Commercial licence (exclusive or non exclusive)

LactXpress® patent references:

• Patent file n°FR 9816462 entitled: «Gram positive bacteria deprived of HtrA proteasic activity and their uses », extended in Europe, the US and Canada.
• Patent file n°FR0210805 entitled: « Zinc regulated prokaryotic expression cassettes », extended in Europe, the US and Canada.
• Pending patent application n°FR 0954785 entitled: Promoter sequences for recombinant protein expression in Lactoccocus lactis.