Determination of biosorption potential under in vitro
conditions
To observe morphological changes due to arsenic stress, micrograph of
normal cell (Figure 4a) and arsenic loaded (Figure 4c) was compared
using SEM. B. mycoides. NR5 expressed distinct morphology and
appeared as tangled mass because of its cellular morphology. The cells
with no arsenic appeared normal while in arsenic stress condition,
visible changes on cell surface morphology were seen as swollen and
large in size which possibly indicated the accumulation of heavy metal.
Along with SEM micrograph estimation of arsenic through EDS also showed
the presence of arsenic metal over microbial cell surface (Figure 4d)
whereas, no arsenic was recorded in control bacterial cell surface
(Figure 4b). On the other hand, Transmission Electron Micrograph ofBacillus mycoides NR-5 having large irregular cells also shows
surface deposition as well as intracellular accumulation of arsenic
(Figure 5 a & b). Result of TEM analysis also supports observation of
SEM that such morphological changes might have happened due to
interaction of cells to arsenic.