外源添加维生素C对链霉菌ε-聚赖氨酸发酵的影响  

Effects of exogenous addition of vitamin C on ε-poly-L-lysine fermentation by Streptomyces

作　　者：孙浩本 颜鹏[1] 陆鹏麒 毛忠贵[2] 唐蕾[1,2] SUN Hao-ben;YAN Peng;LU Peng-qi;MAO Zhong-gui;TANG Lei(Key Laboratory of Industrial Biotechnology,Ministry of Education,Jiangnan University,Wuxi 214122,China;School of Biotechnology,Jiangnan University,Wuxi 214122,China)

机构地区：[1]江南大学,工业生物技术教育部重点实验室,江苏无锡214122 [2]江南大学生物工程学院,江苏无锡214122

出　　处：《食品与发酵工业》2018年第9期29-35,共7页Food and Fermentation Industries

基　　金：国家自然科学基金(21376106)；111引智计划(111-2-06)；江苏省现代工业发酵协同创新中心资助。

摘　　要：采用荧光染色分析ε-聚赖氨酸(ε-poly-L-lysine,ε-PL)产生菌Streptomyces sp. AF3-44在摇瓶发酵过程中胞内活性氧类(reactive oxygen species,ROS)水平与菌体活力,比较添加Vc对ε-PL产量、抗氧化酶类活性、总抗氧化能力、细胞膜脂成分及细胞氧化损伤的影响,并在5 L发酵罐上对比了添加Vc后分批发酵过程参数的变化。在摇瓶发酵过程中,随着p H值降低和ε-PL浓度的上升,Streptomyces sp. AF3-44胞内ROS累积,菌体活力下降;而Vc的添加提高了细胞的总抗氧化能力及膜脂中不饱和脂肪酸所占比例,减少了氧化损伤;在5 L发酵罐中添加Vc,分批发酵44 h,ε-PL产量为7. 73 g/L,为不添加Vc发酵的1. 5倍。通过外源添加抗氧化剂,增强菌体抗氧化能力,减少氧化损伤,为提升链霉菌ε-PL的发酵水平提供了一种新的策略。ε-Poly-L-lysine(ε-PL)is a short peptide formed by condensation ofα-COOH andε-NH2 of L-lysine.ε-PL has wide application but its fermentation yield by Streptomyces is low.To investigate the effects of exogenous addition of vitamin C on the anti-oxidative damage andε-poly-L-lysine(ε-PL)by Streptomyces.AF3-44.The reactive oxygen species(ROS)level and the cell viability ofε-PL producing Streptomyces sp.AF3-44 during shake-flask fermentation were analyzed by fluorescent dye detection.Theε-PL level,the antioxidant enzymes activities,the total antioxidant capacity,the changes of membrane lipid composition and the oxidative damage with and without Vc addition were compared.The parameters during the batch fermentation on a 5 L fermenter scale with and without Vc addition were measured.The intracellular ROS level increased whereas the cell viability decreased with the decrease of pH and increase ofε-PL during shake-flask fermentation.The addition of Vc increase the total antioxidant capacity and the ratio of unsaturated fatty acids,and reduced the oxidative damage.In batch fermentation on a 5 L fermenter scale,the titer ofε-PL was 7.73 g/L at 44 h with Vc addition,which was 1.5 fold of the control.The exogenous addition of antioxidant could increase cell's anti-oxidative ability and reduce oxidative damage,which provided a novel strategy forε-PL improvement by Streptomyces.

关 键 词：维生素C(VC) 链霉菌 Ε-聚赖氨酸 氧化损伤 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]