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.