脱氮菌株的诱变育种及其脱氮条件的优化

Mutation Breeding of Denitrogenation Strain and Optimization of the Denitrify Condition

以一株具有脱氮功能的玫瑰色微球菌（Micrococcus roseus）为出发菌株，经紫外线（UV）、硫酸二乙酯（DES）、氯化锂（LiCl）诱变剂反复诱变处理，并通过纳氏试剂法初筛和氨氮滴定法复筛，得到一株脱氮能力较强的菌株Mc32m脱氮率比出发菌株提高了36．8％。采用正交设计实验优化Mc32菌株的脱氮条件，优化后的菌株脱氮率达到74％，多次传代实验表明该菌株遗传稳定性较好。

Ultraviolet （UV） radiation, Diethy sulfate （DES） and LiC1 mutagenesis were performed on original strain-Micrococcus roseus with denitrify function. A strain Mc32 with upper denitrify capability was obtained through preliminary screening of Nessler method and rescreening of Azotometry. The denitrogenation rate of strain Mc32 was raised 36.8 % compared with original strain. Denitrify condition of strain Mc32 was optimized through orthogonal design experiment, and denitrogenation rate of post-optimized strain was 74 %. Several passages experiment indicated that genetic stability of the strain was better.