链霉菌ε-聚赖氨酸发酵过程中的氧化胁迫效应

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

摘要:

【目的】探究ε-聚赖氨酸(ε-PL)产生菌对pH和ε-PL的耐受性、氧化胁迫与ε-PL合成之间的关系。【方法】选取3株ε-PL产生菌Streptomyces sp. AF3-44、Streptomyces sp. AS32和Streptomyces albulus F15，比较其在发酵性能、pH和ε-PL耐受性以及抗氧化胁迫能力上的差异，并对菌株发酵过程的活性氧成因进行分析。【结果】在3株菌中AF3-44具有最强的pH和ε-PL耐受性及抗氧化胁迫能力，因而在发酵后期能够保持良好的细胞活性和最高的ε-PL浓度；ε-PL引起的氧化胁迫主要发生在发酵前期，而发酵中后期氧化胁迫的产生主要由酸性pH导致。【结论】提高链霉菌ε-PL发酵过程中的抗氧化胁迫能力，可提升菌体活力和发酵水平。

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.