Abstract: To screen high ε-polylysine-producing mutants of Streptomyces albulus, the methods of protoplast preparation, regeneration and mutagenesis were established. Thereafter, the protoplasts of the original strain were treated by pulsed-ligh and He-Ne laser. The double layer culture medium test proved that the H/C value of mutation is 0.28～0.45 cm, bigger than that of the original strain. The fermentation result showed its ε-polylysine productivity is higher 40% than that of the original strain.

Key words: &epsilon, -polylysine； Streptomyces albulus； protoplast； mutation