Abstract:

For possessing independent intellectual property rights and meeting the needs of high-yield production strains of nuclease P1, 2%RNA was used as the unique carbon and nitrogen sources of the screening culture medium, 65 strains which could produce nuclease P1 were screened from citrus orchard soil. Strain YC34 was used as the mutation breeding starting strain with the highest enzyme activity to 127.3 U/mL, after treated by complex mutagenesis of UV, microwave and LiCl mutation, the high-yield strainYC34-1 was obtained. The crude nuclease P1 activity of broth was increased to 360.7 U/mL, 183.3% higher than the original strain YC34, which had good potential in application. The preliminary morphological results showed that the strain YC34 was identified to be Penicillium citrinum.