Oxidative stress in ε-poly-L-lysine fermentation by Streptomyces

Abstract:

[Objective] to study the relationship between the tolerance of pH and ε-PL, oxidative stress and ε-poly-L-lysine (ε-PL) synthesis in ε-PL producing strain. [Methods] The fermentation activities, pH and ε-PL tolerance, and antioxidative abilities among Streptomyces sp. AF3-44, Streptomyces sp. AS32 and Streptomyces albulus F15 were compared, and the cause for reactive oxygen species generation was analyzed. [Results] AF3-44 had the best pH and ε-PL tolerance and antioxidative ability among three tested strains, and kept good cell activity with the highest ε-PL concentration. ε-PL caused the oxidative stress at the earlier but pH at the later stage of fermentation. [Conclusion] improvement of the antioxidative ability in ε-PL fermentation by Streptomyces could increase the cell activity and ε-PL level in fermentation.