RESUMO
From air bacteria capable of decomposing creatinine, three single independent strains K9510、K9511 and K9512 have been isolated. The highest creatinine amidohydrolase (EC 3.5.2.10; creatininase) producing strain K9510 was screened out. The strain K9510 was identified as Pseudomonas sp. The results of culture condition for creatininase formation by strain K9510 were obtained as follows: creatinine and creatine were found to be the effective inducers for enzyme formation; the solution of mixed metallic salts could stimulate cell growth and enzyme formation. The suitable medium for creatininase formation was consisted of 0.9% creatinine、 0. 15% yeast extract、 0. 09% malt extract、0.05% NH4C1 and some amount of the solution of mixed metallic salts at pH5. 5. When the bacterium was grown in 250mL conic flask containing 50mL of the medium mentioned above on the rotary shaker(250r/min) at 35℃ for 33 h, about 50 u creatininase was obtained.