10.22376/ijpbs.2019.10.1.p1-12 Volume 5 Issue 3 2014 (July- September) For the optimization of culture conditions, incubation time study of cellulase production by lessThan i greaterThan Bacillus subtilis lessThan /i greaterThan KG10 was showed remarkable enzyme activity (0.24±0.01 U/ml) and protein content (43±2.83 µg/ml), after 32 h of incubation. The effects of various carbon and nitrogen sources tested; maximum cellulase production was recorded in CMC (0.24±0.01 U/ml) and yeast extract (0.35±0.02 U/ml), respectively. The effect of various pH and temperature examined, the maximum enzyme production was obtained in the pH 7.0 (0.35±0.02 U/ml) and 37°C (0.38±0.02 U/ml). The role of metal ions and NaCl concentration on cellulase production tested, among the metal ions, calcium chloride (0.40±0.01 U/ml) and 0.5% of NaCl concentration supported maximum enzyme production (0.43±0.01 U/ml). Whereas, the inoculums load 2% supported maximum (0.48±0.02 U/ml). The cellulase enzyme was purified through a two step chromatography which includes DEAE sepharose and sephadex G75 column chromatography. SDS-PAGE analysis of the purified cellulase enzyme revealed a single band with the molecular mass of 56 kDa. The pH stability studies revealed that purified cellulase was 100% stable over a broad pH range of 6–11 for 12 h. The optimum temperature was 50°C. However, the temperatures of 55, 60 and 65°C, the purified cellulase exhibited 92, 87 and 75% residual activity. The zymogram and biostoning of the cellulase enzyme activity effectively degraded and removed cellulose and stain, respectively. RAMALINGAM KOWSALYA AND RAMASAMY GURUSAMY Cellulase; Bacillus subtilis; Kovai Kutralam; Biostoning; cellulase purification. 432-448