(VI) and Cr(VI) of D. desulfuricans G20 is related to the action of the thioredoxin
reductase and NADPH (Li and Lee 2009). This suggests that the strain 6SR could
have a resistance mechanism involving enzymatic reduction of Cr(VI), like a
response to the oxidative stress generated by metallic ion.
Fig. 13.12 Phylogenetic tree for the sequence obtained of chrA gene. The analysis was carried out
with 550 aligned amino acids with related sequence to species that exhibit resistance to cadmium.
The tree was built using a maximum likelihood algorithm. The scale bar represents 50 nucleotide
substitutions per 100 amino acid. Bootstrap values, expressed as a percentage of 1000 repetitions,
are shown at branching points. Only values greater than 50% are displayed
13 Heavy Metal Removal Processes by Sulfate-Reducing Bacteria
389
reductase and NADPH (Li and Lee 2009). This suggests that the strain 6SR could
have a resistance mechanism involving enzymatic reduction of Cr(VI), like a
response to the oxidative stress generated by metallic ion.
Fig. 13.12 Phylogenetic tree for the sequence obtained of chrA gene. The analysis was carried out
with 550 aligned amino acids with related sequence to species that exhibit resistance to cadmium.
The tree was built using a maximum likelihood algorithm. The scale bar represents 50 nucleotide
substitutions per 100 amino acid. Bootstrap values, expressed as a percentage of 1000 repetitions,
are shown at branching points. Only values greater than 50% are displayed
13 Heavy Metal Removal Processes by Sulfate-Reducing Bacteria
389