Development of Bacterium-Based Heavy Metal Biosorbents: Enhanced Uptake of Cadmium and Mercury by Escherichia coli Expressing a Metal Binding Motif

Abstract

A gene coding for a de novo peptide sequence containing a metal binding motif was chemically synthesized and expressed inEscherichia coli as a fusion with the maltose binding protein. Bacterial cells expressing the metal binding peptide fusion demonstrated enhanced binding of Cd2+ and Hg2+compared to bacterial cells lacking the metal binding peptide. The potential use of genetically engineered bacteria as biosorbents for the removal of heavy metals from wastewaters is discussed.

Characterization of lactic acid bacteria-based probiotics as potential heavy metal sorbents

“…To select the best strains with excellent metal (Cd or Pb)removal efficiency from water, all identified LAB were employed for metal removing study following the method described by Pazirandeh et al (1998) with some modifications. Freshly cultured LAB were harvested in 2-ml Eppendorf tubes, centrifuged at high speed to pallet the cells and washed twice using sterilized MQ water.…”

Selectivity in the heavy metal removal by exopolysaccharide-producing cyanobacteria

“…However, only a few studies (Gadd 1990;Radway et al 2001) have investigated the possibility of using specific strains for adsorbing specific metals, in spite of the potential usefulness of this feature, being a biosorbent usually utilized in effluents containing other contaminating metals, which may interfere with the removal of the metal of interest. Therefore, recent researches in the area of heavy metal removal from wastewaters and sediments have focused on the development of materials with high affinity and selectivity for target metals (Pazirandeh et al 1998;Stanish and Monbouquette 2000). Recently, it was demonstrated the good sorbent capacity of two exopolysaccharide (EPS)-producing cyanobacteria towards positively charged metal ions (De Philippis et al 2003, 2007Paperi et al 2006), but the metal selectivity of these microbial sorbents has not been investigated in details.…”

Construction and expression of functional multi-domain polypeptides in Escherichia coli: expression of the Neurospora crassa metallothionein gene

“…A redesign strategy was recently described to produce functional polypeptides of about 40 amino acids (Imperiali and Ottesen 1998). Other investigators have also described design strategies for novel functional polypeptides with binding (Regan 1995;Pazirandeh et al 1998) or catalytic activities (Baltzer and Broo 1998;Tuchscherer et al 1998). The potential for the design and production of a polypeptide which is capable of several functions and stable to adverse conditions, such as extreme temperature, pH and salinity (Jaenicke 1991), is currently being investigated.…”

“…The use of genetic engineering to increase the affinity and biosorptive capacity of bacterial cells for heavy metals is a promising area of research for the development of bacterial-based biosorbents. The expression and cellular targeting of high affinity metal-binding proteins such as metallothioneins or de novo metal-binding peptides to increase bacterial heavy metal binding has been reported by several groups (Berka et al 1988;Pazirandeh et al 1995Pazirandeh et al , 1998Sousa et al 1996Sousa et al , 1998Chen and Wilson 1997). Bacterial cells properly expressing and localizing these proteins outside the cytosol have demonstrated enhanced bioaccumulation of target metals.…”