为提高缬氨酸产量，以一株产L-valine的黄色短杆菌(Brevibacterium flavum) BFS为出发菌株，通过He-Ne激光诱变育种，分别设置不同的诱变强度和时间，确定最佳诱变条件为照射功率15 mW、照射时间20 min。对发生正突变的菌株进行L-valine 耐受性筛选，得到的突变菌株产酸量提高了25.50%，并且该菌株可稳定遗传至少10 代。激光诱变是一种安全有效的微生物育种技术，低剂量激光辐射更有利于菌株诱变效果的改善。

To improve the production of L-valine, the He-Ne laser is used for Brevibacterium flavum to induce mutagenesis. The He-Ne laser with different power and duration is tested, and the best laser treatment condition that the intensity and time of irradiation is 15 mW and 20 min, respectively is decided. The positive mutants are selected directionally and stepwise on the agar plates containing extra L-valine of different concentrations, and L-valine overproducing mutant is derived with production increased by 25.50%. The results show that the mutant strain can keep steady properties for at least 10 generations. He-Ne laser is an effective technique for microbial mutagenesis, and the He-Ne laser with low power is suitable for Brevibacterium flavum mutagenesis.