Genetic engineering of Caulobacter for removal of heavy metals
Pollution caused by heavy metals poses risk to humans and the environment, which has led to stringent regulations over the allowable limits of heavy metals in drinking water. Biological remedial treatments have received increased attention in recent years because of their potential for providing a cost-effective approach for heavy metal removal. Through genetic manipulations, we inserted a heavy metal-binding peptide to a permissive site of the surface layer (S-layer) protein of the bacterium Caulobacter crescentus (PMID:19214794). Such engineered recombinant strains not only selectively sequester dissolved heavy metals but also form a monolayer biofilm through their distinctive holdfasts, achieving a single step removal of the contaminants from water (PMID:20069463). This work may be adapted to construct bioreactors and provide a cost-effective solution toward cleaning up heavy metals from aqueous systems (PMID: 21326927).
Fig. 1. Sequestration of heavy metals with engineered Caulobacter cells by combining two powerful technologies: surface display and self-immobilization.
