Seventeen bacterial isolates were screened for their cellulase activity by carboxymethyl cellulose (CMC) plate assay. The bacterial strain K1 showed the largest depolymerized region in CMC plate assay and was further studied for quantitative cellulase activity. On the basis of 16S rDNA sequence analysis, the strain K1 was found to be Bacillus sp. This strain produced the maximum CMCase at pH 6 and 50 A degrees C in the presence of peptone (1 %) as a source of nitrogen. The CMCase activity was stimulated by Ca2+ (2 mM) by 20 % over the control. The CMCase activity of this Bacillus sp. K1 was highly induced when lactose was used as a source of carbon during fermentation.