The purpose of this study was to observe symbiotic prokaryotes under the optical and scanning electron microscope for their morphology and multiple roles including arsenic immobilization in the natural environment. Microbial mats proliferating near to the arsenic contaminated (141 to 997 μg L–1) tube-wells were collected for this study. The results of microscopic observation showed that the symbiotic prokaryotes in microbial mats were mainly consisting of Coccus, Bacillus, and Filamentous microbes associated with photosynthetic Cyanobacteria; enabling to accumulate high concentrations of As (550 mg kg–1). ED-XRF analysis also confirmed the presence of As in microbial mats associated with Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, Fe, Zn and Sr. Henceforth, it can be concluded that the symbiotic prokaryotes can play a significant role in enabling to uptake arsenic from tube-well water, and release O2 in the ambient air simultaneously. Our findings are very encouraging for further research to promote a sustainable mitigation effort for provision of As safe drinking water and a CO2 reduced safer environment.