Isolation of phytase-producing Pseudomonas sp and optimization of its phytase production

Phytase (myo-inositol hexakisphosphate phosphohydrolase, EC 3.1.3.8) catalyzes the hydrolysis of phytate (myo-inositol hexakisphosphate) to release inorganic phosphate. A bacterial strain producing phytase was isolated from soil around a cattle shed. To identify the strain, cellular fatty acids profiles, the GC contents, a quinine-type analysis, and physiological test using an API 20NE kit were carried out. The strain was identified to be a genus of Pseudomonas sp. and named as Pseudomonas sp. YH40. The optimum culture condition for the maximum productivity of phytase by Pseudomonas sp. YH40 were attained in a culture medium composed of 1.0% (w/v) glycerol, 2.0% (w/v) peptone, and 0.2% (w/v) FeSO4.7H(2)O. Within the optimal medium condition, the production of phytase became highest after 10h of incubation, and the maximal phytase production by Pseudomonas sp. YH40 was observed at 37degreesC and pH 6.0.