[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.%[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.[Conclusionl Improvement of the antioxidative ability in ε-PL fermentation by Streptomyces could increase the cell activity and ε-PL level in fermentation.
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