Biorecovery of gold by Escherichia coli and Desulfovibrio desulfuricans

Abstract

Microbial precipitation of gold was achieved using Escherichia coli and Desulfovibrio desulfuricans provided with H2 as the electron donor. No precipitation was observed using H2 alone or with heat-killed cells. Reduction of aqueous AuIII ions by both strains was demonstrated at pH 7 using 2 mM HAuCl4 solution and the concept was successfully applied to recover 100% of the gold from acidic leachate (115 ppm of AuIII) obtained from jewelry waste. Bioreductive recovery of gold from aqueous solution was achieved within 2 h, giving crystalline Au0 particles (20-50 nm), in the periplasmic space and on the cell surface, and small intracellular nanoparticles. The nanoparticle size was smaller (red suspension) at acidic pH (2.0) as compared to that obtained at pH 6.0 and 7.0 (purple) and 9.0 (dark blue). Comparable nanoparticles were obtained from AuIII test solutions and jewelry leachate.

Biorefining of precious metals from wastes: an answer to manufacturing of cheap nanocatalysts for fuel cells and power generation via an integrated biorefinery?

“…In addition to D. desulfuricans and E. coli (Mikheenko et al 2008;Deplanche and Macaskie 2008;Deplanche et al 2010), other organisms with high hydrogenase activity, like Shewanella (De Windt et al, 2005) and Ralstonia (Ludwig et al 2009), can also reduce Pd(II) (Deplanche 2008). Cupriavidus (formerly Ralstonia) metallidurans can biomineralise gold by various mechanisms including its reduction to Au(0) (Reith et al 2009).…”

Simultaneously Discrete Biomineralization of Magnetite and Tellurium Nanocrystals in Magnetotactic Bacteria

“…The crystallization of target molecules within the microorganisms has the potential to provide some advantages over other bioremediation technology, such as increased accumulation efficiency over cell surface adsorption or nonprecipitous uptake within the cell, decreasing the toxicity of the pollutant by reductive (or oxidative) precipitation/crystallization, and additional potential to utilize the pollutant product for further material applications. The uptake and crystallization of Pb(II), Ag(I), Au(III), U(VI), Se(IV), and other metals by many species has been well documented previously (11,14,16,19,24). Some bacteria in particular have been the subject of increased study due to the reduction and crystallization of tellurite within or onto the cell (2,16,25,45).…”

Size-Controlled Production of Gold Bionanoparticles Using the Extremely Acidophilic Fe(III)-Reducing Bacterium, Acidocella aromatica

“…In some studies, the use of H 2 (but not organic acids such as lactate) was essential to support Au(III) reduction [25,26], and the involvement of hydrogenase(s) was suggested in S. algae [25], E. coli and D. desulfuricans [24]. In this study, formate played a role as an effective e-donor.…”

“…Only a few studies used external e-donors, such as H 2 [24][25][26] and lactate [28]. In any case, the size-control of bio-AuNPs by means of external e-donor had not yet been evaluated in detail.…”

“…(a few nano-to micro-size, extra-and intracellular [15][16][17][18][19][20]); Lactobacillus spp. (5-30 nm, intracellular [21]; 20-50 nm and >100 nm, extra-and intracellular [22]); Pseudomonas aeruginosa (15-30 nm, extracellular [23]); Escherichia coli and Desulfovibrio desulfuricans (20-50 nm, intracellular; [24]); a range of dissimilatory Fe(III)-reducing bacteria/archaea including Pyrobaculum islandicum, Pyrococcus furiosus, Thermotoga maritima, Shewanella algae, Geobacter sulfurreducens and Geovibrio ferrireducens (nano-size, intracellular [25,26]); Rhodopseudomonas capsulate (10-20 nm, extracellular [27]); Rhodobacter capsulatus (<50 nm, extra-and intracellular [28]), Stenotrophomonas maltophilia (40 nm, intracellular [29]), Ralstonia metallidurans (extra-and intracellular [30]), sulfate-reducing bacteria (mostly <10 nm, extra-and intracellular [31]), and the radiation-resistant Deinococcus radiodurans (44 nm, extra-and intracellular [32]). …”