show Abstracthide AbstractThe objective of the study was to explore thermophilic bacteria from Tattapani hotspring of Himachal Pradesh, which can be used for decomposition of cellulosic biomass under different polluted environments. We isolated a novel thermophilic bacteria, Geobacillus toebii strain PW12, which showed optimum growth at 75°C (hyperthermophile) and in presence 4.2% NaCl and5.4% KCl (halotolerant). The thermophile bacterial strain produce thermophilic cellulase enzyme, which was predominantly extracellular. The cellulose activity was optimum at 80- 90°C and pH 6 - 8.0. Interestingly, no cellulase activity was observed at temperature less than 40°C, indicating its thermophilic nature. Metal ions such as Mn2+, Co2+ and Fe2+ significantly enhanced the cellulase activity by 2-5 folds. Even Hg2+ (1mM) and Cd2+ (5 mM) slightly enhanced the cellulose activity. The cellulase activity increased by 6 – 39 % in the presence of 0.1 % SDS and Triton X100. Cellulase enzyme activity was increased by 1.6 folds in the presence of 1 mM EDTA. The cellulose enzyme activity was tolerant to toluene, cyclohexane, H2O2, n-butanol, and ethanol. The novel G. toebii PW12 strain could be used in bioremediation of cellulosic biomass and develop new enzymes with thermal, salt, solvent and metal tolerant potential.