induced by cadmium and zinc, and chrA gene is induced by hexavalent chromium
(Naghma et al. 2005; Ding et al. 2005). The molecular analysis with respect to
cadmium and chromium resistance mechanisms demonstrated the presence of cadA
and chrA genes, when the partial sequences were analysed phylogenetically; see
Figs. 13.11 and 13.12. Both genes are induced by Cd, Zn, Pb and Cr; the codified
Fig. 13.9 Transmission electron micrographs of Desulfovibrio alaskensis strain 6SR. (a) Cells of
D. alaskensis strain 6SR stained with lead acetate. (b) D. alaskensis strain 6SR grown in the
presence of 18 mg/L Cr(VI) (72 h incubation)
Fig. 13.10 Schematic diagram of the chromium removal from wastewater by biological sulfide.
(Reported by Peña-Caballero et al. 2016)
13 Heavy Metal Removal Processes by Sulfate-Reducing Bacteria
387
(Naghma et al. 2005; Ding et al. 2005). The molecular analysis with respect to
cadmium and chromium resistance mechanisms demonstrated the presence of cadA
and chrA genes, when the partial sequences were analysed phylogenetically; see
Figs. 13.11 and 13.12. Both genes are induced by Cd, Zn, Pb and Cr; the codified
Fig. 13.9 Transmission electron micrographs of Desulfovibrio alaskensis strain 6SR. (a) Cells of
D. alaskensis strain 6SR stained with lead acetate. (b) D. alaskensis strain 6SR grown in the
presence of 18 mg/L Cr(VI) (72 h incubation)
Fig. 13.10 Schematic diagram of the chromium removal from wastewater by biological sulfide.
(Reported by Peña-Caballero et al. 2016)
13 Heavy Metal Removal Processes by Sulfate-Reducing Bacteria
387