Design

Source of platinum

Platinum leaching makes a accumulation of this metal on the road side. By default, it has been prooved that plants are potentiel bioaccumulator of platinum, which is found concentrated on the roots, leaves.. Otherwise, the metal is also carried on the sewage sludge and is actually an issue regarding the recycling potencial of these sludge

Mobilisation by a siderophore

Improving recoveries of platinum and palladium from oxidized Platinum-group element ores of the Great Dyke, Zimbabwe, using the biogenic siderophore Desferrioxamine B, Dennis Kraemer & al.

In the previous article, authors made bioleaching with synthetised siderophores. By this way, they extracted approximately 80% of the total platinum found in the ore. But we were looking for a synthetic biological approach.

Pathway of the desferrioxamine B biosynthesis

"image voie de biosynthese de siderophore"

Our strategy for the siderophore mobilisation results in two main steps :

Transformation of E.Coli with an inductible plasmide holding the des cluster
Induction and production of the desferrioxamine B

Then the produced siderophore would be transfered in the recuperation solution containing the platinum. Therefore, the platinum and other metal must be recruit by our purified siderophore. Though those siderophores would be import using a sowing of Streptomyces coelicolor . Then simple centrifugation and combustion will concentrate the solution in metal a first time.

Biosorption and reduction

This step aims to :

reduct platinum ions (Platine Pt14) into nanoparticules
bacterial flagellar protein adsorbs ions
the ambient reducer power reduces ions into nanoparticules

Deplanche & al.,2008 or Capeness & al.,2015 have shown that flagellar are high adsorber of platinum. Also, Urartu Ozgur & al., 2011 investigated that peptides can bind precious metal like gold, silver, platinum specifically. The aim of our work is to create a Biobrick containing the flagellar sequence with a transcritpion control under strong promotor. Then on the part of the flagellin faced to the extarnal medium when the polymere is formed, an insertion restriction site will be inserted. Then specific precious metal peptides would be added using this insertion site to increase the level of adsorbsion specificity and yield.