Isolation and characterization of halophilic bacteria from coastal habitats in India for remediation of inorganic pollutants

Halophilic are considered as the industrially important microbes because of their huge potential in biotechnology industries including the treatment of wastewater or industrial effluent containing heavy metal pollutants. Therefore, the present study focuses on the screening and characterization of halophilic bacteria from different habitats of Odisha, a coastal state in India. The presence of Mg, HCO_3-, Cl^-, Fe, Mn and Cu was found in higher concentration in the collected sediment samples. The isolated bacteria were found to be moderately halophilic nature due to their significant growth in 15%-18% (w/v) NaCl. The result showed the utmost number of viable cells (0.022 to 1.75 cfu mL^-1) in 15%-18% (w/v) NaCl concentration. The multi-metal resistance study showed two strains AS’S-I and BB’S-III having resistance upto multi-metal concentration of 1200 mg L^-1. There was visible binding of metals ions unto the cell surface as observed through SEM-EDX. Molecular chracterization identified AS’S-I and BB’S-III strains as Halomonas sp. Bob01 and Halomonas sp. Chl02 respectively. The presence of sodium concentration of 0.07–0.18 mg L^-1 and amino acids such as Arg, Thr, Gln, Glycine, Cys, Met, His were confirmed in the isolated halophiles as osmo-regulators. The biochemical assay showed the presence of catalase, amylase, and urease as antioxidant and essential for the activity of halophilic enzymes attributing to the thriving of the isolated bacteria under high stress condition. Thus, the findings suggest the existence of halophilic bacteria in the coastal areas of Odisha which can be used for remediation of inorganic pollutants.