食品与发酵工业2024，Vol.50Issue(1)：29-36,8.DOI:10.13995/j.cnki.11-1802/ts.035117
小白链霉菌全细胞转化L-赖氨酸合成ε-聚赖氨酸的体系构建与优化
Construction and optimization of whole-cell transformation method for ε-poly-L-lysine production from L-lysine by Streptomyces albulus
摘要
Abstract
Streptomyces albulus is the main producer of ε-poly-L-lysine(ε-PL).ε-PL is a natural antimicrobial peptide used primari-ly as a biological preservative in food industry,but its widespread application is limited by its high costs.To improve the production effi-ciency of S.albulus,this study used a whole-cell transformation method to produce ε-PL.Firstly,the synthesis efficiency of ε-PL in dif-ferent fermentation systems was compared,and the whole-cell transformation system was found to produce the highest ε-PL yield,reaching 10.74 g/L.Then,the transformation medium and conditions were systematically optimized,and the optimal transformation conditions was obtained:glucose 80 g/L,cell culture time 12 h,reaction temperature 30 ℃,L-lysine 15 g/L,citric acid 15 g/L,initial pH 4.0,(NH4)2SO4 6 g/L,and wet biomass 1 900 g/L.In the optimal system,the ε-PL yield and substrate conversion rate reached 13.80 g/L and 38.9％,respectively,which were 4.1 and 3.2 folds higher than those in shake flask fermentation system.Finally,the L-lysine spe-cific permease gene(lysp)from Escherichia coli BL21 was heterologous expressed to enhance the strain's ability to uptake exogenous L-ly-sine.Compared with the starting strain,the recombinant strain S.albulus OE-lysp showed a 26％increase in L-lysine utilization rate and a 33％increase in substrate conversion rate.The ε-PL yield also increased by 17.21 g/L,about 6.4 times higher than that in shake flask fermentation system,which is to our knowledge the highest reported ε-PL production in shake flask fermentation system.The results dem-onstrate the feasibility of producing ε-PL using a whole-cell transformation method and provide a solid technical foundation for the produc-tion of high-value ε-PL using L-lysine.Therefore,this study has important theoretical significance and high economic value.关键词
小白链霉菌/ε-聚赖氨酸/全细胞转化/异源表达/L-赖氨酸通透蛋白Key words
Streptomyces albulus/ε-poly-L-lysine/whole-cell transformation/heterologous expression/L-lysine permeable protein引用本文复制引用
朱道君,刁文娇,张佳微,王靓,张宏建,张建华,陈旭升..小白链霉菌全细胞转化L-赖氨酸合成ε-聚赖氨酸的体系构建与优化[J].食品与发酵工业,2024,50(1):29-36,8.基金项目
国家自然科学基金面上项目(31671846) （31671846）
江苏省重点研发计划项目(BE2022703) （BE2022703）
