Abstract(s) :
(Anglais) Key words: Gaussia luciferase, Chlamydomonas reinhardtii, microalgae, photobioreactor, encapsulation
Currently, several scientific researches threat about culture of microalgae, due to their ability to produce metabolites such as lipids or saccharides. Mass culture of microalgae should allow the production of bio-sourced molecules technologically interesting (bioethanol, biofuel,…).
But microalgae can also produce, in smaller quantity, high added value metabolites, naturally metabolized or resulting from a genetic transformation. Chlamydomonas reinhardtii can be considered as a model strain for this kind of researches. In fact, this microalga can be modified for the purpose of producing and excreting a selected metabolite like recombinant proteins.
However, given the size of microalgae, free cell cultures are not workable to collect molecules from the culture media. The encapsulation of the microalgae in a porous material should be able, at the same time, to hold in microalgae and to allow diffusion of metabolites. The recovery of the metabolites present in the culture medium should therefore be easier.
In this research, Chlamydomonas reinhardtii has been modified to produce Gaussia luciferase [1][2][3], a recombinant protein that has the particularity to emit light in presence of its substrate (coelenterazine).
One of the challenges of the project is the choice of the porous material because it must meet several criteria: biocompatibility, good mechanical resistance and allowing diffusion of nutrients and the excreted metabolite. Alginate and alginate/titanium beads are currently being investigated.
Also, several way for the recovery of Gaussia luciferase are considered. Concentration by molecular weight selective membranes is a promising technique, applicable at lab-scale with centrifugal concentrators and with tangential filtration on larger scale.
* VALOALGUE is part of the global project “Algae Factory”, funded by ERDD