Idea.png Spongeman.PNG


The use of microbial species for environmental remediation of heavy metals has been extensively studied. They can be used to sequester, precipitate or modify heavy metals to detoxify them. Two major inorganic cations of arsenic are both toxic to varying degrees. (See Toxicity).

Storage and binding

Surveying evolved strategies for arsenic detoxification in bacteria shows that the most common mechanisms involve the efflux of arsenic ions. Our goal is to sequester arsenic, therefore to use a microbial chassis we must inhibit its efflux mechanism. However, storage of free arsenic ions in a cell will be toxic. A successful biosequestration strategy needs to also incorporate a binding mechanism that allows the cell to accumulate significant amounts of arsenic.

Arsenic Sponge

This engineered strain of E. coli will absorb arsenic and sequester it, safely removing it from the surrounding environment. This will be accomplished by making it both deficient for the arsenic efflux pump gene and also incorporating an arsenic binding mechanism using metallothioneins. This class of cysteine rich peptides can bind arsenic, as well as other heavy metals, preventing it from interfering with cellular function.