The presence ofHM-associated genes in the AGB-1 isolate was
examined via PCR amplification of selected HM marker genes, and
each expected PCR band was sequenced to confirm detection of the
target gene. AGB-1 carried the ArsB, ACR3(1), aoxB, and bmtA
genes, whereas PCR failed to amplify ArsC and cadR genes. Arsenate
reductase (ArsC gene) reduces arsenate As(V) to arsenite As(III),
which is extruded from cells by the membrane efflux pump ArsB/
ACR3(1) (Mukhopadhyay et al., 2002).