Production, Purification, Characterization and Kinetic studies of Phytase from Enterococcus and Streptococcus spp using submerged fermentation

Phytases (EC 3.1.3.8) refer to group of enzymes that hydrolyze biochemical degradation of myo-inositol hexakis phosphate (phytic acid) liberating myo-inositol, inorganic orthophosphates or free phosphorous. Phytase, being the pre-dominant enzyme in animal feed increases the bioavailability of phosphorous. Following research was concerned with the optimized production, partial purification and characterization of bacterial phytases. Bacterial strains (Enterococcus PhyI, Enterococcus PhyII, Enterococcus PhyIII, and Streptococcus PhyIV), isolated form soil and fecal samples were exploited for phytase production under submerged fermentation. Optimized production of phytase was achieved at temperature of 30 degrees C, pH 7.0 and incubation period of 72-96 hours using M9 medium. Phytase from potential bacterial strains showed optimum activity within a pH range 6.0-7.0 and temperature 50 degrees C. Mn+2 and Mg+2 ions stimulated phytase while Zn+2 and Cu+2 ions posed inhibitory effect. Tween 80 modulated phytase activity. Temperature and pH stability profile of bacterial phytase was examined. Phytase remained fairly stable upto 70 degrees C and tolerated a wide pH range upto pH 8.0 after which a decline trend in enzyme stability was observed.