Isolation, investigation
and identification of arsenic-tolerant bacteria derived from the natural environment
Mandal Sapna, Mandal Keya, Bose Supriya Kumar, Chaudhuri Aparna and Ghosh Sabyasachi
Res. J. Chem. Environ.; Vol. 29(8); 111-119;
doi: https://doi.org/10.25303/298rjce1110119; (2025)
Abstract
Arsenic contamination poses significant environmental and health risks. The current
investigation aims to isolate, characterize and identify arsenic-resistant bacteria
from naturally contaminated soil due to its dual role in enhancing soil fertility
and bioremediation of soil pollution. Soil samples were systematically collected
from arsenic-affected regions and processed using selective enrichment techniques
to isolate resistant strains, which were further screened for tolerance to varying
arsenic concentrations. The minimum inhibitory concentration (MIC) study determined
the highest arsenic levels tolerated by each strain. Biochemical and morphological
characterization assessed the physiological traits of the isolates, while 16S rRNA
gene sequencing facilitated their molecular identification. Biochemical analyses
highlighted metabolic variations in response to arsenic exposure. Fourier Transform
Infrared (FTIR) spectroscopy was utilized for metabolic profiling, revealing functional
groups associated with arsenic resistance.
Among the isolates, a rod-shaped and Gram-positive Bacillus sp. (in: firmicutes)
was identified (NCBI accession number PQ061509), exhibiting the highest MIC value
of 38 mM for As(III) and 440 mM for As(V). The identified strains demonstrated high
arsenic tolerance and diverse metabolic capabilities, underscoring their potential
for bioremediation applications. These findings enhance our understanding of microbial
adaptations in arsenic-polluted environments and emphasize the role of arsenic-tolerant
bacteria in environmental remediation and sustainable soil management.
