A potent phytase-producing bacterium Bacillus lehensis MLB2 was isolated from bean-grown soil. The optimum conditions recorded after optimization were 24 h incubation time, pH 5.5, 37°C, 2% inoculum level, 0.5% rice bran and 0.5% potassium nitrate. An overall 3.144-fold enhancement in phytase production was achieved after optimization. The use of an inexpensive substrate rice bran and short incubation period make the phytase production cost effective. The purified phytase (152.9 U/mg) had a molecular mass of approximately 98.686 kDa as determined by sodium dodecyl sulphatepolyacryalamide gel electrophoresis and confirmed by liquid chromatography-mass spectrometry, optimum pH of 4.5, and temperature of 37°C. It maintained maximum stability in the acidic region from pH 2.0 to 6.0 and retained 100% at 60◦C or below. It showed an enhanced activity in the presence of 5 mM K