Dehalogenation of chlorinated aromatic compounds using a hybrid bioinorganic catalyst on cells of Desulfovibrio desulfuricans

Abstract

A novel bioinorganic catalyst was obtained via reduction of Pd(II) to Pd0 on to the surface of cells of Desulfovibrio desulfuricans at the expense of H2. Palladised biomass, supplied with formate or H2 as an electron donor, catalysed the dehalogenation of 2-chlorophenol and polychlorinated biphenyls. In the example of 2,3,4,5-tetrachlorobiphenyl, the bioinorganic catalyst promoted a rate of chloride release of 9.33 +/- 0.17 nmol min(-1) mg (-1) and only approximately 5% of this value was obtained using chemically reduced or commercially available Pd0. In the case of 2,2',4,4',6,6'-hexachlorobiphenyl the rate was more than four orders of magnitude faster than the degradation reported using a sulfidogenic culture. Negligible chloride release occurred from any of the chloroaromatic compounds using biomass alone, or from palladised biomass challenged with hexane carrier solvent only. Analysis of the spent solution showed that in addition to catalysis of reductive dehalogenation the new material was able to remove very effectively the organic residua, with neither any PCB nor any breakdown products identifiable by GC/MS.

Size control and catalytic activity of bio-supported palladium nanoparticles

“…The cells initially adsorb Pd(II), which is then reduced to Pd(0) when an external electron donor, like hydrogen or formate, is added. The following Gram negative and positive bacteria have been used to recover Pd(0) from a Pd(II) solution or directly from industrial waste: Gram negative: Cupriavidus necator [35,37,38], Pseudomonas putida [37,38], Paracoccus denitrificans [38], Desulfovibrio desulfuricans [36,[39][40][41][42][43][44][45], Desulfovibrio fructosivorans [46], Shewanella oneidensis [47][48][49] Cupriavidus metallidurans [35], Esherichia coli [36] and Gram positive: Bacillus licheniformis [50], Bacillus sphearicus [51], and Clostridium pasteurianum [52]. The biosupported Pd(0) was catalytically active towards hydrogenation reactions [53,54], carbon-carbon bond forming reactions [35,37], as well as the reduction of Cr(VI) [41][42][43], dehalogenation reactions [39,[44][45][46]53], reduction of perchlorate [48] and the reduction of hypophosphite [38,40].…”

Characterization of a Recombinant Thermostable Dehalogenase Isolated from the Hot Spring Thermophile Sulfolobus tokodaii

“…Dehalogenases, enzymes that catalyze the cleavage of carbon-halogen bonds, are of particular practical interests because of their potential biotechnological applications in the bioremediation of halogenated environmental pollutants [3][4][5][6][7][8][9][10][11][12][13][14] and the production of enantiomerically pure precursor materials for compound synthesis in the pharmaceutical, fine chemical, and medical industries. In the current study, we cloned, over-expressed, and characterized a dehalogenase from the thermophile Sulfolobus tokodaii.…”

Biocatalytic dechlorination of trichloroethylene with bio‐palladium in a pilot‐scale membrane reactor

“…They showed the superior characteristics of this catalyst towards the dehalogenation of respectively PCB's and lindane. Baxter-Plant et al (2004) used the bacterium Desulfovibrio desulfuricans to produce bio-Pd and used this as a catalyst for the dehalogenation of PCB's and chlorophenols. The production process of bio-Pd is a simple, cost effective, and environmentally friendly technology.…”